Module:Params/doc

The <syntaxhighlight lang="wikitext" inline></syntaxhighlight> module is designed to be adopted by those templates that want to have a deep control of their parameters. It is particularly useful to variadic templates, to which it offers the possibility to count, list, map and propagate the parameters received without knowing their number in advance.

The module offers elegant shortcuts to non variadic templates as well. Outside templates it has very few applications; hence, if you plan to make experiments, make sure to do them from within a template, or you will not be able to see much (you can use {{Template sandbox}} for that). Under ./testcases you can find helper templates that can be specifically used for testing the module's capabilities in flexible ways. Finally, under ./doc/examples you can find some of the examples shown in this documentation page.

Note: In case your template uses <syntaxhighlight lang="wikitext" inline></syntaxhighlight>, please add <syntaxhighlight lang="wikitext" inline></syntaxhighlight> to its documentation page, so that if breaking changes will be introduced in the future the template will be easily traceable without performing an "in source" search.

Please, do not edit this module without having done extensive testing in the module's sandbox first.

General usage

Among the possibilities that the module offers there is that of performing a series of actions after additional arguments have been concatenated to templates' incoming parameters. As this makes it necessary to keep the argument slots clean from interference, instead of named arguments in order to specify options this module uses piping functions (i.e. functions that expect to be piped instead of returning to the caller), or modifiers. This creates a syntax similar to the following example:

<syntaxhighlight lang="wikitext"></syntaxhighlight>

For instance, as the name suggests, the list function lists the parameters wherewith a template was called. By default it does not add delimiters, but returns an indistinct blob of text in which keys and values are sticked to each other. However, by using the setting modifier, we are able to declare a key-value delimiter (p) and an iteration delimiter (i). And so, if we imagined a template named <syntaxhighlight lang="wikitext" inline> </syntaxhighlight> containing the following wikitext,

<syntaxhighlight lang="wikitext"></syntaxhighlight>

and such template were called with the following parameters,

<syntaxhighlight lang="wikitext"> </syntaxhighlight>

the following result would be produced:

Beast of Bodmin: A large feline inhabiting Bodmin Moor
Morgawr: A sea serpent
Owlman: A giant owl-like creature

We can also do more sophisticated things; for instance, by exploiting the possibility to set a header (h) and a footer (f), we can transform the previous code into a generator of definition lists,

<syntaxhighlight lang="wikitext"></syntaxhighlight>

thus yielding:

Beast of Bodmin

A large feline inhabiting Bodmin Moor

Morgawr

A sea serpent

Owlman

A giant owl-like creature

By placing the with_name_matching modifier before the list function we will be able to filter some parameters out – such as, for instance, all parameter names that do not end with an "n":

<syntaxhighlight lang="wikitext"></syntaxhighlight>

Thus, the previous code will produce:

Beast of Bodmin

A large feline inhabiting Bodmin Moor

Owlman

A giant owl-like creature

This mechanism has the intrinsic advantage that it allows the concatenation of infinite modifiers. And so, in order to get the accurate result that we want to obtain we could write:

<syntaxhighlight lang="wikitext"></syntaxhighlight>

Most modifiers immediately affect what follows, while others add their action to the queue of actions that will be done last, thus affecting only the way functions behave (e.g. sequential, non-sequential, all_sorted, reassorted – these are called “flag modifiers”). A rule of thumb in the nomenclature is the following:

• If a directive is an English adjective or a past participle it is a flag modifier (e.g. sequential)
• If a directive is or contains an English gerundive it is a modifier (with the exception of the special, first-position-only new directive – e.g. squeezing)
• If a directive is anything else (usually an English bare infinitive) it is a normal non-piping function (e.g. list_values)

The two flag modifiers sequential and non-sequential refer to a technical jargon used in wikitext: given a parameter list, the subgroup of sequential parameters is constituted by the largest group of consecutive numeric parameters starting from |1= – this is known as the parameters' "sequence". A parameter list that does not have a first parameter specified does not possess a sequence.

Considerations on code style

Normally on Wikipedia, when templates are written across multiple lines in block style, by convention the pipe sign (|) is written on the left side of each new line, as in the following example:

<syntaxhighlight lang="wikitext">Bloggs, Joe(1974)Book of Bloggs</syntaxhighlight>

Doing the same with <syntaxhighlight lang="wikitext" inline></syntaxhighlight> however is often impossible, because the module tends to preserve trailing spaces and new lines in all its arguments except in modifier and function names (and, accordingly, a newline character would be parsed as belonging to the last parameter of each line). Because of this, the only safe and meaningful way to invoke this module in block style is by appending the pipe sign at the end of the line, right before a modifier name or a function name, as in the following example:

<syntaxhighlight lang="wikitext"></syntaxhighlight>

Prototyping new templates

In designing new templates or exploring the module's capabilities, there are two possible approaches that allow to simulate the incoming parameters direcly in a preview window—without having to save the changes first and then test them from a different page. The first approach consists in temporarily exploiting the <syntaxhighlight lang="wikitext" inline></syntaxhighlight> and <syntaxhighlight lang="wikitext" inline>...</syntaxhighlight> tags properly to include the template's transclusion as well, the second approach consists in temporarily relying on the imposing modifier.

For instance, given a template named <syntaxhighlight lang="wikitext" inline>Template:My template</syntaxhighlight>, whose wikitext is <syntaxhighlight lang="wikitext" inline></syntaxhighlight>, to simulate the transclusion <syntaxhighlight lang="wikitext" inline>Template:My template</syntaxhighlight>, it is possible to write, temporarily,

<syntaxhighlight lang="wikitext">Template:My template</syntaxhighlight>

or, equivalently,

<syntaxhighlight lang="wikitext"></syntaxhighlight>

and then click on “Show preview”. In both cases, the final template must be eventually saved as:

<syntaxhighlight lang="wikitext">

   📄 Template documentation

   Module:Params/doc/doc

</syntaxhighlight>

Functions

Here follows the list of functions. You might want to see also § Flag modifiers and § Modifiers.

self

Brief

Return the name of the current template

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This argumentless function guarantees that the name of the template invoking this module is shown, regardless if this is transcluded or not.

As a possible example, if a Wikipedia page named Page X contained only a transclusion of a template named <syntaxhighlight lang="wikitext" inline>Template:Foobar</syntaxhighlight>, and the latter contained the following wikitext,

<syntaxhighlight lang="wikitext">

Module:Params/doc</syntaxhighlight>

if we visited Template:Foobar we would see,

Template:Foobar

Template:Foobar

whereas if we visited Page X we would see:

Template:Foobar

Page X

Therefore by writing

<syntaxhighlight lang="wikitext">Page is being transcluded</syntaxhighlight>

it is possible to understand whether a page is being transcluded or not. For most cases the <includeonly>...</includeonly> and <noinclude>...</noinclude> will offer a simpler solution, however there can be cases in which this becomes the way to go.

If Page X transcluded <syntaxhighlight lang="wikitext" inline>Template:Foobar 2</syntaxhighlight> and the latter were a redirect to <syntaxhighlight lang="wikitext" inline>Template:Foobar</syntaxhighlight>, we would still see

Template:Foobar

Page X

A typical use case of this function is that of providing stable links for editing transcluded templates. E.g.:

<syntaxhighlight lang="wikitext"><span class="noprint plainlinks" title="Edit ">[{{fullurl:|action=edit}} edit this template]</syntaxhighlight>

Another possible use case is that of transcluding a subtemplate. E.g.:

<syntaxhighlight lang="wikitext">{{/my subtemplate|foo|bar}}</syntaxhighlight>

count

Brief

Count the number of parameters wherewith a template was called

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This function does not take arguments.

The number that this function yields depends on the modifiers that precede it. For instance, in a template that is called with both named and unnamed parameters,

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

and

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

will return different results.

concat_and_call

Brief

Prepend positive numeric arguments to the current parameters, or impose non-numeric or negative numeric arguments, then propagate everything to a custom template

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This function comes in handy in case of wrapper templates. For example, if our <syntaxhighlight lang="wikitext" inline></syntaxhighlight> had the following code,

<syntaxhighlight lang="wikitext"></syntaxhighlight>

and were called with,

<syntaxhighlight lang="wikitext"></syntaxhighlight>

the following call to the <syntaxhighlight lang="wikitext" inline>Template:Foobar</syntaxhighlight> template would be performed:

<syntaxhighlight lang="wikitext">Template:Foobar</syntaxhighlight>

By using the cutting modifier it is possible to impose numeric positive parameters instead of prepending them. For instance, the following code echoes all incoming parameters to <syntaxhighlight lang="wikitext" inline>Template:My template</syntaxhighlight>, with the exception of |3=, which is replaced with hello world:

<syntaxhighlight lang="wikitext"></syntaxhighlight>

If the numeric parameters to replace are a limited number, as in the example above, a better alternative to cutting might be imposing.

If no other argument besides the template name is provided this function simply echoes the current parameters to another template.

Note: All arguments passed to this function except the template name will not be trimmed of their leading and trailing spaces. The concat_and_call function name itself, however, will be trimmed of its surrounding spaces.

concat_and_invoke

Brief

Prepend positive numeric arguments to the current parameters, or impose non-numeric or negative numeric arguments, then propagate everything to a custom module

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

Exactly like concat_and_call, but invokes a module instead of calling a template.

Note: All arguments passed to this function except the module name and the function name will not be trimmed of their leading and trailing spaces. The concat_and_invoke function name itself, however, will be trimmed of its surrounding spaces.

concat_and_magic

Brief

Prepend positive numeric arguments to the current parameters, or impose non-numeric or negative numeric arguments, then propagate everything to a custom parser function

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

Exactly like concat_and_call, but calls a parser function instead of a template.

Note: All arguments passed to this function except the magic word will not be trimmed of their leading and trailing spaces. The concat_and_magic function name itself, however, will be trimmed of its surrounding spaces.

value_of

Brief

Get the value of a single parameter

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

Without modifiers this function is similar to writing <syntaxhighlight lang="wikitext" inline></syntaxhighlight>. With modifiers, however, it allows reaching parameters that would be unreachable without knowing their number in advance. For instance, writing

<syntaxhighlight lang="wikitext"></syntaxhighlight>

will expand to the value of the second-last sequential parameter, independently of how many parameters the template was called with. If no matching parameter is found this function expands to nothing. A header (h), a footer (f), and a fallback text (n) can be declared via the setting modifier – the strings assigned to the key-value pair delimiter (p), the iteration delimiter (i), the last iteration delimiter (l) and the "serial-comma-like" last iteration delimiter (s) will be ignored.

For instance, the {{If then show}} template could be rewritten as

<syntaxhighlight lang="wikitext"></syntaxhighlight>

Simplifying, the following wikitext expands to the first parameter that is not empty:

<syntaxhighlight lang="wikitext"></syntaxhighlight>

Whereas the following wikitext expands to the first parameter that is not blank (i.e. neither empty nor containing only whitespaces)

<syntaxhighlight lang="wikitext"></syntaxhighlight>

list

Brief

List the template parameters (both their names and their values)

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This function does not take arguments.

If the setting modifier was not placed earlier, this function will not add delimiters, but will return an indistinct blob of text in which keys and values are sticked to each other. A header (h), a key-value pair delimiter (p), an iteration delimiter (i), a last iteration delimiter (l), a "serial-comma-like" last iteration delimiter (s), a footer (f), and a fallback text (n) can be declared via setting.

For example, the following code

<syntaxhighlight lang="wikitext"></syntaxhighlight>

will generate an output similar to the following.

Parameters passed: Owlman (A giant owl-like creature); Beast of Bodmin (A large feline inhabiting Bodmin Moor); Morgawr (A sea serpent)

list_values

Brief

List the values of the incoming parameters

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This function does not take arguments.

The sequential modifier often accompanies this function. If the setting modifier was not placed earlier, this function will not add delimiters, but will return an indistinct blob of text in which values are sticked to each other. A header (h), an iteration delimiter (i), a last iteration delimiter (l), a "serial-comma-like" last iteration delimiter (s), a footer (f), and a fallback text (n) can be declared via setting – the string assigned to the key-value pair delimiter (p) will be ignored.

For example, the following code

<syntaxhighlight lang="wikitext"></syntaxhighlight>

will generate an output similar to the following.

Values of parameters passed: A giant owl-like creature; A large feline inhabiting Bodmin Moor; A sea serpent.

This function covers and extends all the cases covered by {{}}. For instance, the following two examples with “ + ” as delimiter and “ ... ” as conjunction produce a similar result:

1. <syntaxhighlight lang="wikitext" inline></syntaxhighlight>
2. <syntaxhighlight lang="wikitext" inline></syntaxhighlight>

list_maybe_with_names

Brief

List the values of sequential parameters and the names and the values of non-sequential parameters

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This function does not take arguments. It is a combination of list and list_values: if a parameter belongs to the parameter sequence only its value will be shown, otherwise both its name and its value will be shown. If the setting modifier was not placed earlier, this function will not add delimiters, but will return an indistinct blob of text in which keys and values are sticked to each other. A header (h), a key-value pair delimiter (p), an iteration delimiter (i), a last iteration delimiter (l), a "serial-comma-like" last iteration delimiter (s), a footer (f), and a fallback text (n) can be declared via setting.

For example, the following code in <syntaxhighlight lang="wikitext" inline>Template:My template</syntaxhighlight>,

<syntaxhighlight lang="wikitext"></syntaxhighlight>

when transcluded as <syntaxhighlight lang="wikitext" inline>Template:My template</syntaxhighlight>, will generate an output similar to the following.

Parameters passed: one; two; three; four; hello→world; foo→bar.

This function is particularly useful to mimic the natural transclusion of templates.

coins

Brief

Associate custom strings to possible parameter values and list the custom string when the associated value is present

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This function is identical to the unique_coins function, except that it allows the repetition of identical flags. See there for more information.

unique_coins

Brief

Associate custom strings to possible parameter values and list the custom string when the associated value is present, but not more than once

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This function is used to detect the existence of flag parameters. For this reason, it is often accompanied by the sequential modifier (or, equivalently, by ...|excluding_non-numeric_names|clearing|...). For a similar function that allows the repetition of identical flags, see the coins function.

A typical use case of this function is that of constructing URLs. For example, the following template named <syntaxhighlight lang="wikitext" inline> </syntaxhighlight> checks for the html, xml, comments and removenowiki flags in order to append respectively the following strings to the final URL: &wpGenerateRawHtml=1, &wpGenerateXml=1, &wpRemoveComments=0, &wpRemoveNowiki=1.

<syntaxhighlight lang="wikitext"></syntaxhighlight>

And so, when transcluded as,

<syntaxhighlight lang="wikitext"> </syntaxhighlight>

it will generate the following output:

Module:Params/doc/examples/link to expanded template

A copy of the example above is available at {{./doc/examples/link to expanded template}}.

If the setting modifier was not placed earlier, this function will not add delimiters, but will return an indistinct blob of text in which values are sticked to each other. A header (h), an iteration delimiter (i), a last iteration delimiter (l), a "serial-comma-like" last iteration delimiter (s), a footer (f), and a fallback text (n) can be declared via setting – the string assigned to the key-value pair delimiter (p) will be ignored.

call_for_each

Brief

For each parameter passed to the current template, call a custom template with at least two parameters (key and value)

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

Some functions are like shortcuts. The X_for_each|F functions are similar to mapping_by_X(ing)|F|(names_and_values|)list_values. The latter syntax (i.e. the modifier version) allows a values_and_names flag to invert the order from key-value to value-key.

All unnamed arguments following the template name will be placed after the key-value pair. Named arguments will be passed verbatim. A header (h), an iteration delimiter (i), a last iteration delimiter (l), a "serial-comma-like" last iteration delimiter (s), a footer (f), and a fallback text (n) can be declared via the setting modifier – the string assigned to the key-value pair delimiter (p) will be ignored.

Calling a template for each key-value pair with

<syntaxhighlight lang="wikitext"></syntaxhighlight>

will be different from writing

<syntaxhighlight lang="wikitext"></syntaxhighlight>

In the first example each key-value pair will be passed to the <syntaxhighlight lang="wikitext" inline>Template:Foobar</syntaxhighlight> template, while in the second example the $# and $@ tokens will be expanded after the <syntaxhighlight lang="wikitext" inline>Template:Foobar</syntaxhighlight> template has been called. In most cases this will make no difference, however there are several situations where it will lead to nonsensical results.

Note: All arguments passed to this function except the template name will not be trimmed of their leading and trailing spaces. The call_for_each function name itself, however, will be trimmed of its surrounding spaces.

invoke_for_each

Brief

For each parameter passed to the current template, invoke a custom module function with at least two arguments (key and value)

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

Exactly like call_for_each, but invokes a module instead of calling a template.

Invoking a module function for each key-value pair with

<syntaxhighlight lang="wikitext"></syntaxhighlight>

will be different from writing

<syntaxhighlight lang="wikitext"></syntaxhighlight>

In the first example each key-value pair will be passed to the <syntaxhighlight lang="wikitext" inline></syntaxhighlight> module function, while in the second example the $# and $@ tokens will be expanded after the module function has been invoked. There might be cases in which this will make no difference, however there are several situations where it will lead to nonsensical results.

Note: All arguments passed to this function except the module name and the function name will not be trimmed of their leading and trailing spaces. The invoke_for_each function name itself, however, will be trimmed of its surrounding spaces.

magic_for_each

Brief

For each parameter passed to the current template, call a magic word with at least two arguments (key and value)

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

Exactly like call_for_each, but calls a parser function instead of a template.

Note: All arguments passed to this function except the magic word will not be trimmed of their leading and trailing spaces. The magic_for_each function name itself, however, will be trimmed of its surrounding spaces.

call_for_each_value

Brief

For each parameter passed to the current template, call a custom template with at least one parameter (i.e. the parameter's value)

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

The sequential modifier often accompanies this function. All unnamed arguments following the template name will be appended after the value parameter. Named arguments will be passed verbatim. A header (h), an iteration delimiter (i), a last iteration delimiter (l), a "serial-comma-like" last iteration delimiter (s), a footer (f), and a fallback text (n) can be declared via the setting modifier – the string assigned to the key-value pair delimiter (p) will be ignored.

For example, calling {{tl}} with each parameter can be done by writing

<syntaxhighlight lang="wikitext"></syntaxhighlight>

This will be different from writing

<syntaxhighlight lang="wikitext"></syntaxhighlight>

In the first example each value will be passed to the {{tl}} template, while in the second example the $@ token will be expanded after the {{tl}} template has been called. Here this will make no difference, however there are several situations where it will lead to nonsensical results.

Note: All arguments passed to this function except the template name will not be trimmed of their leading and trailing spaces. The call_for_each_value function name itself, however, will be trimmed of its surrounding spaces.

invoke_for_each_value

Brief

For each parameter passed to the current template, invoke a custom module function with at least one argument (i.e. the parameter's value)

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

Exactly like call_for_each_value, but invokes a module instead of calling a template.

Invoking a module function for each value with

<syntaxhighlight lang="wikitext"></syntaxhighlight>

will be different from writing

<syntaxhighlight lang="wikitext"></syntaxhighlight>

In the first example each value will be passed to the <syntaxhighlight lang="wikitext" inline></syntaxhighlight> module function, while in the second example the $@ token will be expanded after the module function has been invoked. There might be cases in which this will make no difference, however there are several situations where it will lead to nonsensical results.

Note: All arguments passed to this function except the module name and the function name will not be trimmed of their leading and trailing spaces. The invoke_for_each_value function name itself, however, will be trimmed of its surrounding spaces.

magic_for_each_value

Brief

For each parameter passed to the current template, call a magic word with at least one argument (i.e. the parameter's value)

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

Exactly like call_for_each_value, but calls a parser function instead of a template.

For example, if a template had the following code,

<syntaxhighlight lang="wikitext"></syntaxhighlight>

and were transcluded as <syntaxhighlight lang="wikitext" inline> </syntaxhighlight>, the {{urlencode:...|QUERY}} parser function would be called for each incoming parameter as first argument and with QUERY as second argument, and finally the returned text would be prefixed with &preloadparams%5b%5d=. This would generate,

&preloadparams%5b%5d=hello+world&preloadparams%5b%5d=%C3%A0%C3%A8%C3%AC%C3%B2%C3%B9&preloadparams%5b%5d=foo+bar

which can be used to allow the creation of pages with preloaded text and parameters.

Note: All arguments passed to this function except the magic word will not be trimmed of their leading and trailing spaces. The magic_for_each_value function name itself, however, will be trimmed of its surrounding spaces.

call_for_each_group

Brief

Call a custom template for each group of parameters that have the same numeric suffix

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

The custom template will be repeatedly called with the numeric id of the group (i.e. the numeric suffix) as parameter zero (i.e. {{{0}}}). This will be an empty string for the group of incoming parameters that do not have a numeric suffix. A hyphen before the numeric suffix will be interpreted as a minus sign (and therefore the group id will be treated as a negative number). Numeric incoming parameters will be treated as if their prefix is an empty string (these can be captured using {{{}}} or {{{|fallback text}}} in the callback template). Spaces between the prefix and the numeric suffix will be ignored (therefore writing |foobar123= will be identical to writing |foobar 123= – in case of collisions one of the two values will be discarded). In the unlikely scenario that the prefix is itself a number (e.g. |1 1=, |2 1=, etc.), if this is 0 or a negative number it will be decreased by one unit in order to leave the parameter zero undisturbed (so 0 will become -1, -1 will become -2, and so on – if needed, you can use ...|purging|0|1|... in the callback template to renormalize these numbers).

All unnamed arguments that follow the template name in the invocation of this module will appear as sequential parameters in each call. Named arguments will be passed verbatim. Both named and unnamed arguments passed to this function will be given precedence in case of collisions. Numeric argument names below 1 will be decreased by one unit (i.e. ...|call_for_each_group|example template|0=Hello world|... will become |-1=Hello world in the callback template – see above).

A header (h), an iteration delimiter (i), a last iteration delimiter (l), a "serial-comma-like" last iteration delimiter (s), a footer (f), and a fallback text (n) can be declared via the setting modifier – the string assigned to the key-value pair delimiter (p) will be ignored.

If you are a module writer, you might recognize some distant similarities between this function and TableTools.affixNums.

For example, if a template named <syntaxhighlight lang="wikitext" inline>Template:Foobar</syntaxhighlight> contained the following code,

<syntaxhighlight lang="wikitext"></syntaxhighlight>

writing

<syntaxhighlight lang="wikitext">Template:Foobar</syntaxhighlight>

will be equivalent to writing

<syntaxhighlight lang="wikitext"> </syntaxhighlight>

The modifiers sequential, non-sequential, all_sorted and reassorted will affect what groups of parameters will be iterated, not what parameters will be grouped. Before calling this function you will likely want to reduce the list of parameters via one of the with_*_matching group of modifiers (for instance ...|with_name_matching|.%-%d+$|or|[^%-]%d+$|call_for_each_group|... leaves only the parameters in which both the prefix and the numeric suffix are not empty strings). The reassorted modifier often accompanies this function.

Warning In writing templates, there is often the habit of signaling multilevel substitutions using the <syntaxhighlight lang="wikitext" inline>safesubst:</syntaxhighlight> notation. This is a dangerous practice, because <syntaxhighlight lang="wikitext" inline>safesubst:</syntaxhighlight> means "write the parameter with an empty name, otherwise write safesubst:". Due to the fact that call_for_each_group can pass parameters with an empty name, a callback template should never use <syntaxhighlight lang="wikitext" inline>safesubst:</syntaxhighlight> to notate multilevel substitutions, but should use instead <syntaxhighlight lang="wikitext" inline>safesubst:</syntaxhighlight>. Not following this advice can lead to bugs that are hard to debug.

At {{./doc/examples/list of authors}} you can find an example of how to use this function to list authors the same way {{Cite book}} does. For instance, writing

<syntaxhighlight lang="wikitext">Module:Params/doc/examples/list of authors</syntaxhighlight>

will generate

Module:Params/doc/examples/list of authors

See also {{./doc/examples/tablebox}} for an example of how to exploit this function to create infoboxes, and {{./doc/examples/four cells per row table}} for an example of how to exploit this function to create n-column tables.

Note: All arguments passed to this function except the template name will not be trimmed of their leading and trailing spaces. The call_for_each_group function name itself, however, will be trimmed of its surrounding spaces.

for_each

Brief

For each parameter passed to the current template, expand all occurrences of $# and $@ within a given text as key and value respectively

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

Example:

<syntaxhighlight lang="wikitext"></syntaxhighlight>

The text returned by this function is not expanded further (currently this module does not offer an expand_for_each function). If you need wikitext expansion, use either concat_and_call to propagate the incoming parameters altogether to the {{for nowiki}} template, or mapping_by_calling to propagate the incoming parameters one by one to {{expand wikitext}}.

Example #1 (wikitext expanded via the {{for nowiki}} template – suggested):

<syntaxhighlight lang="wikitext"></syntaxhighlight>

Example #2 (wikitext expanded via the {{expand wikitext}} template – less efficient but more flexible):

<syntaxhighlight lang="wikitext"></syntaxhighlight>

Note: The argument passed to this function will not be trimmed of its leading and trailing spaces. The for_each function name itself, however, will be trimmed of its surrounding spaces.

Flag modifiers (piping functions)

The following are flag modifiers, i.e. functions that add their action to the queue of actions that will be done last, and which expect to be piped instead of returning to the caller. Each of them can be followed by either another flag modifier or a modifier or a non-piping function. The order in which flag modifiers appear has no consequences. The actions that flags do affects only functions, but do not affect modifiers.

sequential

Brief

(In functions only, does not affect modifiers) Reduce the parameter list to the subgroup of consecutive parameters that follow |1=

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

Example:

<syntaxhighlight lang="wikitext"></syntaxhighlight>

This modifier does not take arguments besides the name of the function that will follow.

Using sequential together with non-sequential will generate an error.

Note: Like non-sequential, the sequential modifier permanently marks a query. For instance, writing <syntaxhighlight lang="wikitext" inline></syntaxhighlight> will first mark the query as "sequential", then will discard the first element from the sequence (leaving all the others intact). And so, no matter how many other parameters will be present, nothing will be shown.

non-sequential

Brief

(In functions only, does not affect modifiers) Reduce the parameter list by discarding the subgroup of consecutive parameters that follow |1=

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

Example:

<syntaxhighlight lang="wikitext"></syntaxhighlight>

This modifier does not take arguments besides the name of the function that will follow.

Using non-sequential together with sequential will generate an error.

Note: Like sequential, the non-sequential modifier permanently marks a query, and no matter what transformations will follow (see squeezing) the parameters' "sequence" will not be shown.

all_sorted

Brief

(IN FUNCTIONS ONLY, DOES NOT AFFECT MODIFIERS) When the time will come, all parameters will be dispatched sorted: first the numeric ones in ascending order, then the rest in natural order

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

Note: This modifier sorts the way functions iterate across all parameters based on their names. If you want to sort sequential parameters based on their values, see sorting_sequential_values.

Example:

<syntaxhighlight lang="wikitext"></syntaxhighlight>

This modifier does not take arguments besides the name of the function that will follow.

Normally only sequential parameters are dispatched sorted, whereas non-sequential ones are dispatched randomly. The all_sorted modifier ensures that nothing is left out of (natural) order. Attention must be paid to the fact that parameters whose name is a negative number will appear first. To avoid this the squeezing modifier can be used.

The all_sorted modifier only affects the way parameters are shown, but has no effects on functions that do not iterate or cannot impose an order, such as:

• count
• value_of
• concat_and_call
• concat_and_invoke
• concat_and_magic

Note: The all_sorted modifier cannot be used with functions that propagate several parameters together in a single call, like concat_and_call, concat_and_invoke, and concat_and_magic, because during a call the order of arguments is always lost. For the same reason, it is not possible to guess the order of named parameters a template was transcluded with.

reassorted

Brief

(IN FUNCTIONS ONLY, DOES NOT AFFECT MODIFIERS) When the time will come, all parameters will be dispatched sorted: first non numeric ones in natural order, then the numeric ones in ascending order

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This modifier is similar to all_sorted, but numbers are iterated last (as in "bar, foo, hello, zebra, 1, 2, 3, …").

Note: The reassorted modifier cannot be used with functions that propagate several parameters together in a single call, like concat_and_call, concat_and_invoke, and concat_and_magic, because during a call the order of arguments is always lost. For the same reason, it is not possible to guess the order of named parameters a template was transcluded with.

Modifiers (piping functions)

The following are modifiers, i.e. functions that expect to be piped instead of returning to the caller. Each of them can be followed by either another modifier or a flag modifier or a non-piping function. The actions that modifiers do are done sequentially, in the same order chosen during the invocation of this module.

setting

Brief

Define glue strings

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This modifier allows some internal variables to be set and later be used (currently only by functions). It takes a variable number of arguments, relying on the first argument to understand how many other arguments to read. A few examples will introduce it better than words:

• <syntaxhighlight lang="wikitext" inline></syntaxhighlight>

  ↳ Set the value of iteration delimiter to |, then list all values

• <syntaxhighlight lang="wikitext" inline></syntaxhighlight>

  ↳ Set the value of both header text and iteration delimiter to |, then list all values

• <syntaxhighlight lang="wikitext" inline></syntaxhighlight>

  ↳ Set the value of both header text and iteration delimiter to |, set key-value pair delimiter to =, then list all parameters

• <syntaxhighlight lang="wikitext" inline></syntaxhighlight>

  ↳ Set the value of both header text and iteration delimiter to |, set key-value pair delimiter to =, set fallback text to No parameters were passed, then list all parameters

The first argument is a slash-separated list of lists of slots to assign; one slot is referred by exactly one character and each list of slots maps exactly one argument. A slot indicates which internal variable to set. If more than one slot is aggregated within the same slash-separated list the same text will be assigned to more than one variable.

The slots available are the following:

Slots	Variable	Description
p	Key-value pair delimiter	The string of text that will be placed between each parameter name and its value; it is never inserted by functions that only iterate between values, or by functions that pass the key-value pairs to external calls.
i	Iteration delimiter	The string of text that will be placed between each iteration; it is never inserted unless there are two or more parameters to show when l is not given, or three or more parameters when l is given.
l	Last iteration delimiter	The string of text that will be placed between the second last and the last iteration; it is never inserted unless there are two or more parameters to show; if omitted it defaults to i.
s	"Serial-comma-like" last iteration delimiter	The string of text that will be placed between the second last and the last iteration when there are three or more parameters to show; if omitted it defaults to l.
h	Header text	The string of text that will be placed before the iteration begins; it is never inserted if there are no parameters to show.
f	Footer text	The string of text that will be placed after the iteration is over; it is never inserted if there are no parameters to show.
n	Fallback text	The string of text that will be placed if there are no parameters to show.

All space characters in the directives argument are discarded. Therefore writing <syntaxhighlight lang="wikitext" inline></syntaxhighlight> will be equivalent to writing

<syntaxhighlight lang="wikitext"></syntaxhighlight>

In theory, instead of assigning different arguments at once (i.e. <syntaxhighlight lang="wikitext" inline></syntaxhighlight>), it is possible to write separate invocations of setting for each argument, as in <syntaxhighlight lang="wikitext" inline></syntaxhighlight>. This method however will be slightly less efficient.

The s slot has been created with the Oxford comma in mind. For instance, the following imaginary <syntaxhighlight lang="wikitext" inline>Template:Foobar see also</syntaxhighlight> template adds a comma before the "and" conjunction when more than two page names are provided:

<syntaxhighlight lang="wikitext"></syntaxhighlight>

You can find this example at {{./doc/examples/Oxford comma}}. Thus, <syntaxhighlight lang="wikitext" inline>Module:Params/doc/examples/Oxford comma</syntaxhighlight> will generate

Note: The setting modifier name will be trimmed of its surrounding spaces. The directives argument will be stripped of all space characters, including internal spaces. All other arguments passed to this modifier will be parsed verbatim (i.e. leading and trailing spaces will not be removed).

squeezing

Brief

Rearrange all parameters that have numeric names to form a compact sequence starting from 1, keeping the same order

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

Example:

<syntaxhighlight lang="wikitext"></syntaxhighlight>

This modifier does not take arguments besides the name of the function that will follow. If you are a module writer, you might recognize some similarities between this function and TableTools.compressSparseArray.

The following three concatenations will lead to the same result of discarding all parameters with numeric names:

1. <syntaxhighlight lang="wikitext" inline></syntaxhighlight>
2. <syntaxhighlight lang="wikitext" inline></syntaxhighlight>
3. <syntaxhighlight lang="wikitext" inline></syntaxhighlight>
4. <syntaxhighlight lang="wikitext" inline></syntaxhighlight>

The first solution is the most optimized one. Furthermore, in the last two solutions the numeric parameters are discarded just before the final function is invoked (sometimes this might be a wanted result).

filling_the_gaps

Brief

Assign an empty string to all undefined numeric parameters between 1 or a lower numeric parameter name provided and the maximum numeric parameter provided

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

Example:

<syntaxhighlight lang="wikitext"></syntaxhighlight>

This modifier does not take arguments besides the name of the function that will follow.

Note that when all numeric parameters are lower than 1, the gap between 1 and the lowest numeric parameter will not be filled. The following table provides some examples.

Numeric parameters provided

Before calling filling_the_gaps	After calling filling_the_gaps
|1=...	|1=...
|2=...	|1=, |2=...
|6=..., |9=...	|1=, |2=, |3=, |4=, |5=, |6=..., |7=, |8=, |9=...
|-5=..., |-3=...	|-5=..., |-4=, |-3=...
|-5=..., |-3=..., |1=...	|-5=..., |-4=, |-3=..., |-2=, |-1=, |0=, |1=...
|-1=...	|-1=...
|-2=...	|-2=...

Note: There is a safety limit of at most 1024 undefined parameters that can be filled using this modifier.

clearing

Brief

Remove all numeric parameters that are not in the sequence

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This modifier does not take arguments besides the name of the function that will follow.

Unlike sequential – which affects only the way parameters are shown – this modifier actually removes all non-sequential numeric parameters, albeit leaves non-numeric parameters intact.

Example:

<syntaxhighlight lang="wikitext"></syntaxhighlight>

If you want to remove also non-numeric parameters, add the excluding_non-numeric_names modifier:

<syntaxhighlight lang="wikitext"></syntaxhighlight>

If you want instead to remove sequential parameters and leave the rest, use <syntaxhighlight lang="wikitext" inline></syntaxhighlight>:

<syntaxhighlight lang="wikitext"></syntaxhighlight>

cutting

Brief

Remove zero or more parameters from the beginning and the end of the parameters' sequence

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

The first argument indicates how many sequential parameters must be removed from the beginning of the parameter sequence, the second argument indicates how many sequential parameters must be removed from the end of the parameter list. If any of the two arguments contains a negative number its absolute value indicates what must be left on the opposite side – i.e. <syntaxhighlight lang="wikitext" inline></syntaxhighlight> indicates that the last three arguments must not be discarded.

Example:

<syntaxhighlight lang="wikitext"></syntaxhighlight>

If the absolute value of the sum of the two arguments (left and right cut) is greater than the number of sequential parameters available, the behavior will be the same as if the sum had been equal to the number of sequential parameters available, both when this is a positive value and when it is a negative value (with opposite results). After the desired sequential parameters have been discarded, all other positive numeric parameters will be shifted accordingly.

In some cases it might be necessary to concatenate more than one invocation of the cutting modifier. For instance, the following code prints the last unnamed parameter passed, but only if at least two parameters were passed:

<syntaxhighlight lang="wikitext"></syntaxhighlight>

Suggestion: Although <syntaxhighlight lang="wikitext" inline></syntaxhighlight> de facto gets rid of all sequential parameters, in most cases it is clearer and more idiomatic to write <syntaxhighlight lang="wikitext" inline></syntaxhighlight> to obtain the same effect. The last method however cannot be used when it is important that sequential parameters are removed before a particular modifier is called, because non-sequential does not take effect until the final function is invoked. Writing instead <syntaxhighlight lang="wikitext" inline></syntaxhighlight> will leave zero arguments to show.

cropping

Brief

Remove zero or more parameters from the beginning and the end of the list of numeric parameters (not only the sequential ones)

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This modifier is very similar to cutting, but instead of removing arguments from the extremities of the parameters' sequence, arguments will be removed counting from the first and the last numeric arguments given (i.e. |-1000=... and |1000=... in the case of <syntaxhighlight lang="wikitext" inline>Template:Foobar</syntaxhighlight>). If any of the two arguments contains a negative number its absolute value indicates what must be left on the opposite side.

Example:

<syntaxhighlight lang="wikitext"></syntaxhighlight>

For instance, when a template transcluded as <syntaxhighlight lang="wikitext" inline> </syntaxhighlight> uses the cutting modifier with 2 and 1 as arguments, the following parameters are left:

-2: minus two

0: zero

16: nineteen

17: twenty

If instead the template were to use the cropping modifier with 2 and 1 as arguments, as in the example above, the following parameters would be left:

0: zero

1: one

2: two

3: three

19: nineteen

If the absolute value of the sum of the two arguments (left and right crop) is greater than the difference between the largest and the lowest numeric parameters available, the behavior will be the same as if the sum had been equal to the number of numeric parameters available, both when this is a positive value and when it is a negative value (with opposite results). When sequential parameters are present among the discarded parameters, all the remaining numeric parameters greater than zero will be shifted accordingly.

purging

Brief

Remove zero or more parameters from any point of the list of numeric parameters, shifting everything accordingly

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

The first argument indicates at which point in the parameter list the removal must begin, the second argument indicates how many parameters must be discarded among it and what lies on the right side. If the second argument contains zero or a negative number its absolute value indicates what must be left at the end of the right side of the list of numeric parameters – i.e. <syntaxhighlight lang="wikitext" inline></syntaxhighlight> indicates that every numeric argument whose numeric name is greater than 4 must be removed.

Example #1 (purge the first parameter):

<syntaxhighlight lang="wikitext"></syntaxhighlight>

Example #2 (purge the second, third, and four parameters):

<syntaxhighlight lang="wikitext"></syntaxhighlight>

backpurging

Brief

Remove zero or more parameters from any point of the list of numeric parameters, moving backwards and shifting everything accordingly

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

The first argument indicates at which point in the parameter list the removal must begin, the second argument indicates how many parameters must be discarded among it and what lies on the left side. If the second argument contains zero or a negative number its absolute value indicates what must be left at the end of the left side of the list of numeric parameters – i.e. <syntaxhighlight lang="wikitext" inline></syntaxhighlight> indicates that every numeric argument whose numeric name is less than 6 must be removed.

Example:

<syntaxhighlight lang="wikitext"></syntaxhighlight>

The following code removes all parameters with negative and zero numeric names, then lists the rest:

<syntaxhighlight lang="wikitext"></syntaxhighlight>

reversing_numeric_names

Brief

Reverse the order of all numeric parameters (not only sequential ones), making sure that the largest numeric parameter and |1= are swapped

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This modifier does not take arguments besides the name of the function that will follow.

Example:

<syntaxhighlight lang="wikitext"></syntaxhighlight>

An example that uses this function is available at {{./doc/examples/watchlist}}.

Note: If negative parameters are present this function becomes non-invertible. This means that <syntaxhighlight lang="wikitext" inline></syntaxhighlight> will not restore the original parameter names, but will shift all numeric parameters so that what formerly was the smallest parameter name will now become |1=.

sorting_sequential_values

Brief

Sort the order of sequential values

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

Note: This modifier sorts sequential parameters based on their values. If you want to sort the way functions iterate across all parameters based on their names, see all_sorted.

This modifier optionally supports one argument to specify the sorting criterion. Currently the only possible criterions are alphabetically, for ordering sequential values in alphabetical sort order, and naturally, for ordering sequential values in natural sort order. If this argument is omitted it defaults to alphabetically.

Example (alphabetical sort order):

<syntaxhighlight lang="wikitext"></syntaxhighlight>

Example (natural sort order):

<syntaxhighlight lang="wikitext"></syntaxhighlight>

imposing

Brief

Impose a new value to a parameter

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

Example:

<syntaxhighlight lang="wikitext"></syntaxhighlight>

Note: The value assigned will not be trimmed of its leading and trailing spaces. The name of the parameter and the imposing modifier name itself, however, will be trimmed of their surrounding spaces.

providing

Brief

Assign a new value to a parameter, but only when missing

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

Example:

<syntaxhighlight lang="wikitext"></syntaxhighlight>

Note: The value assigned will not be trimmed of its leading and trailing spaces. The name of the parameter and the providing modifier name itself, however, will be trimmed of their surrounding spaces.

discarding

Brief

Discard one or more numeric parameters or one non-numeric parameter

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

If, and only if, the name of the parameter is numeric, it is possible to add a second argument to indicate how many contiguous parameters must be discarded starting from the first argument. If the discarded parameters is part of the parameters' sequence one or more holes will be created. To avoid creating holes, use purging or backpurging.

Example #1 (discard the parameter named |hello=):

<syntaxhighlight lang="wikitext"></syntaxhighlight>

Example #2 (discard the parameter named |5=):

<syntaxhighlight lang="wikitext"></syntaxhighlight>

Example #3 (discard the parameters named |1=, |2=, |3= and |4=):

<syntaxhighlight lang="wikitext"></syntaxhighlight>

It is possible to use this modifier to check for unknown parameters:

<syntaxhighlight lang="wikitext"></syntaxhighlight>

You can find this example at {{./doc/examples/check for unknown parameters}}. For instance, <syntaxhighlight lang="wikitext" inline>Module:Params/doc/examples/check for unknown parameters</syntaxhighlight> will generate

Module:Params/doc/examples/check for unknown parameters

For simple cases like this, however, specialized modules are available; you might want to have a look at:

{{}}

{{}}

{{}}

{{}}

{{}}

When used to discard single parameters, this modifier is equivalent to writing ...|with_name_not_matching|parameter name|strict|.... However, due to the fact that with_name_not_matching needs to cross-check for the possible presence of or keywords, using discarding will be slightly more efficient.

Note: All arguments passed to this modifier and the discarding modifier name itself will be trimmed of their surrounding spaces.

excluding_non-numeric_names

Brief

Discard all non-numeric parameters

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This modifier is only syntax sugar for ...|with_name_matching|^%-?%d+$|... (but using a slighly faster optimization). For the inverse modifier, see excluding_numeric_names. If you want to remove also non-sequential parameters, add the clearing modifier to the pipeline (...|excluding_non-numeric_names|clearing|...).

excluding_numeric_names

Brief

Discard all numeric parameters (not only the sequential ones)

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This modifier is only syntax sugar for ...|with_name_not_matching|^%-?%d+$|... (but using a slighly faster optimization). For the inverse modifier, see excluding_non-numeric_names.

with_name_matching

Brief

Discard all parameters whose name does not match any of the given patterns

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

Internally this modifier uses Lua's string.find() function to find whether parameter names match against given patterns; therefore, unless a plain flag is set, please use the same syntax of Lua patterns. The plain flag can be either plain or strict or omitted. When omitted it is assumed that the target string is a Lua pattern. The difference between plain and strict is that the latter also requires that the lengths match (this happens only when the two strings are 100% identical). In order to facilitate wikitext scripting in the plain flag argument, the pattern keyword is available too, equivalent to omitting the argument.

To express a logical OR the or keyword is available. To express a logical AND instead, concatenate more invocations of with_name_matching.

For the sake of argument we will imagine that we are invoking with_name_matching from within the {{Infobox artery}} template, and this is being called with the following parameters:

<syntaxhighlight lang="wikitext"> </syntaxhighlight>

Test cases:

• List only the parameters whose names match against the ^Image pattern:

  ↳ <syntaxhighlight lang="wikitext" inline></syntaxhighlight>

  ↳ |Image={{Heart diagram 250px}}|Image2=Alveoli diagram.png

• List the parameters whose names match against both patterns ^Image and %d+$:

  ↳ <syntaxhighlight lang="wikitext" inline></syntaxhighlight>

  ↳ |Image2=Alveoli diagram.png

• List the parameters whose names match against either the ^Name or the ^Latin$ pattern:

  ↳ <syntaxhighlight lang="wikitext" inline></syntaxhighlight>

  ↳ |Latin=truncus pulmonalis, arteria pulmonalis|Name=Pulmonary artery

• List the parameters whose names match against either the ma plain string or the me$ pattern:

  ↳ <syntaxhighlight lang="wikitext" inline></syntaxhighlight>

  ↳ |Image={{Heart diagram 250px}}|Name=Pulmonary artery|Image2=Alveoli diagram.png

Using with_name_matching it is easy to emulate the behaviour of Module:Enumerate (or similar modules). For instance, the following examples creates a bullet list of all the parameters passed of type |foobar1, |foobar2 … |foobarN:

<syntaxhighlight lang="wikitext"></syntaxhighlight>

It is possible to see this example live at {{./doc/examples/enumerate}}.

Note: The target arguments passed to this modifier will not be trimmed of their leading and trailing spaces. The or, plain, strict and pattern keywords, and the with_name_matching modifier name itself, however, will be trimmed of their surrounding spaces.

with_name_not_matching

Brief

Discard all parameters whose name matches all the given patterns

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

Internally this modifier uses Lua's string.find() function to find whether parameter names match against given patterns; therefore, unless a plain flag is set, please use the same syntax of Lua patterns. The plain flag can be either plain or strict or omitted. When omitted it is assumed that the target string is a Lua pattern. The difference between plain and strict is that the latter also requires that the lengths match (this happens only when the two strings are 100% identical). In order to facilitate wikitext scripting in the plain flag argument, the pattern keyword is available too, equivalent to omitting the argument.

To express a logical OR the or keyword is available. To express a logical AND instead, concatenate more invocations of with_name_not_matching.

For the sake of argument we will imagine that we are invoking with_name_not_matching from within the {{Infobox artery}} template, and this is being transcluded using the same parameters that we had imagined in the previous example at with_name_matching:

• List only the parameters whose names do not match against the a pattern:

  <syntaxhighlight lang="wikitext" inline></syntaxhighlight>

  ↳ |Precursor=truncus arteriosus|Supplies=|Vein=pulmonary vein

• List the parameters whose names do not match against the a plain string and do not match against the l plain string either:

  <syntaxhighlight lang="wikitext" inline></syntaxhighlight>

  ↳ |Precursor=truncus arteriosus|Vein=pulmonary vein

• List the parameters whose names do not match against either the a plain string or the n plain string:

  <syntaxhighlight lang="wikitext" inline></syntaxhighlight>

  ↳ |Precursor=truncus arteriosus|Supplies=|Image={{Heart diagram 250px}}|Name=Pulmonary artery|Image2=Alveoli diagram.png|Vein=pulmonary vein

* For the sake of efficiency, please don't use this modifier with the strict flag unless accompanied by or, use discarding instead!

Note: The target arguments passed to this modifier will not be trimmed of their leading and trailing spaces. The or, plain, strict and pattern keywords, and the with_name_not_matching modifier name itself, however, will be trimmed of their surrounding spaces.

with_value_matching

Brief

Discard all parameters whose value does not match any of the given patterns

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

Exactly like with_name_matching, but applied to parameter values instead of names.

Internally this modifier uses Lua's string.find() function to find whether parameter names match against given patterns; therefore, unless a plain flag is set, please use the same syntax of Lua patterns. The plain flag can be either plain or strict or omitted. When omitted it is assumed that the target string is a Lua pattern. The difference between plain and strict is that the latter also requires that the lengths match (this happens only when the two strings are 100% identical). In order to facilitate wikitext scripting in the plain flag argument, the pattern keyword is available too, equivalent to omitting the argument.

Example:

<syntaxhighlight lang="wikitext"></syntaxhighlight>

Note: The target arguments passed to this modifier will not be trimmed of their leading and trailing spaces. The or, plain, strict and pattern keywords, and the with_value_matching modifier name itself, however, will be trimmed of their surrounding spaces.

with_value_not_matching

Brief

Discard all parameters whose value matches all the given patterns

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

Exactly like with_name_not_matching, but applied to parameter values instead of names.

Internally this modifier uses Lua's string.find() function to find whether parameter names match against given patterns; therefore, unless a plain flag is set, please use the same syntax of Lua patterns. The plain flag can be either plain or strict or omitted. When omitted it is assumed that the target string is a Lua pattern. The difference between plain and strict is that the latter also requires that the lengths match (this happens only when the two strings are 100% identical). In order to facilitate wikitext scripting in the plain flag argument, the pattern keyword is available too, equivalent to omitting the argument.

For instance, before calling list, the following code will get rid of all blank parameters (i.e. parameters whose values contain only zero or more spaces):

<syntaxhighlight lang="wikitext"></syntaxhighlight>

A typical use case of this modifier is that of purging all empty incoming parameters before calling another template, especially when this distinguishes between empty and undefined parameters.

<syntaxhighlight lang="wikitext"></syntaxhighlight>

Note: The target arguments passed to this modifier will not be trimmed of their leading and trailing spaces. The or, plain, strict and pattern keywords, and the with_value_not_matching modifier name itself, however, will be trimmed of their surrounding spaces.

trimming_values

Brief

Remove leading and trailing spaces from values

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This modifier does not take arguments besides the name of the function that will follow.

Most modifiers are order-dependent, therefore placing trimming_values in different positions can generate different results. For instance, imagining our <syntaxhighlight lang="wikitext" inline> </syntaxhighlight> being called with the following spaced arguments: <syntaxhighlight lang="wikitext" inline> </syntaxhighlight>. If <syntaxhighlight lang="wikitext" inline> </syntaxhighlight> contained the following code,

<syntaxhighlight lang="wikitext"></syntaxhighlight>

the following text would be printed: 1=wanna|2=be|3=my|4=friend|5=?. But if instead it contained the following code,

<syntaxhighlight lang="wikitext"></syntaxhighlight>

no arguments would be shown.

Order affects also performance, and how many values will be trimmed of their leading and trailing spaces will depend on where trimming_values is placed. For instance, if a template were invoked with 50 parameters and its code contained <syntaxhighlight lang="wikitext" inline></syntaxhighlight>, first all its values would be trimmed of leading and trailing blank spaces and then its first 49 parameters would be discarded. On the other hand, writing <syntaxhighlight lang="wikitext" inline></syntaxhighlight> would first discard 49 parameters and then trim the only value left, resulting in a more efficient code. As a general rule, placing trimming_values as the last modifier is usually the best choice.

In most cases placing trimming_values together with non-sequential will result in an empty call with no effects, because non-sequential parameters are normally stripped of their leading and trailing spaces by default – this however depends on the caller, and if the current template is being called by a module it is in theory possible in specific conditions for named parameters to retain their leading and trailing spaces (namely in non-sequential numeric parameters).

Using trimming_values makes this module behave like other Wikipedia modules behave. For example, if we wanted to emulate

{{}}, writing

<syntaxhighlight lang="wikitext"></syntaxhighlight>

will be equivalent to writing,

<syntaxhighlight lang="wikitext"></syntaxhighlight>

whereas writing

<syntaxhighlight lang="wikitext"></syntaxhighlight>

will be equivalent to writing

<syntaxhighlight lang="wikitext"></syntaxhighlight>

The {{./doc/examples/trim and call}} example template shows how to call any arbitrary template trimming all parameters beforehand.

mapping_to_lowercase

Brief

Convert all parameter values to lower case

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This modifier does not take arguments besides the name of the function that will follow.

This modifier converts all parameter values to lower case. It is identical to writing ...|mapping_by_magic|lc|..., but without the burden of calling a parser function.

mapping_to_uppercase

Brief

Convert all parameter values to upper case

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This modifier does not take arguments besides the name of the function that will follow.

This modifier converts all parameter values to upper case. It is identical to writing ...|mapping_by_magic|uc|..., but without the burden of calling a parser function.

mapping_by_calling

Brief

Map all parameter values, replacing their content with the expansion of a given template repeatedly called with one parameter (the parameter's value)

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This modifier (temporarily) changes the content of the parameters the current template is being called with, replacing each of them with the text returned by another template. The latter will be repeatedly called with at least one parameter as first sequential parameter: the parameter's value.

It is possible to pass the parameter's value as a different parameter, or pass the parameter's name as well, by specifying a call style flag immediately after the template name (see below).

If the call style flag or (if omitted) the template name is followed by one or more groups of three arguments led by the let keyword (i.e. let|name|value), these will be passed to the mapping template.

If the last group of three arguments or (if omitted) the call style flag or (if omitted) the template name is followed by a number, this will be parsed as the amount of positional parameters to add. These will always follow the current parameter's name and/or value if any of the latter are passed using a numeric name greater than zero.

In case of collisions, the parameters assigned via the let keyword will be given precedence over everything else.

For instance, before listing all parameters,

<syntaxhighlight lang="wikitext"></syntaxhighlight>

will replace each value with the expansion of <syntaxhighlight lang="wikitext" inline>Template:Foobar</syntaxhighlight> (where VALUE indicates each different value).

On the other hand,

<syntaxhighlight lang="wikitext"></syntaxhighlight>

will do the same, but using the expansion of <syntaxhighlight lang="wikitext" inline>Template:Foobar</syntaxhighlight> (where NAME and VALUE indicate each different name and value).

Possible call style flags are:

Call style flag	Example	Corresponding call
names_and_values	<syntaxhighlight lang="wikitext" inline></syntaxhighlight>	<syntaxhighlight lang="wikitext" inline> </syntaxhighlight>
values_and_names	<syntaxhighlight lang="wikitext" inline></syntaxhighlight>	<syntaxhighlight lang="wikitext" inline> </syntaxhighlight>
names_only	<syntaxhighlight lang="wikitext" inline></syntaxhighlight>	<syntaxhighlight lang="wikitext" inline> </syntaxhighlight>
values_only	<syntaxhighlight lang="wikitext" inline></syntaxhighlight>	<syntaxhighlight lang="wikitext" inline> </syntaxhighlight>
names_and_values_as|...|...	<syntaxhighlight lang="wikitext" inline></syntaxhighlight>	<syntaxhighlight lang="wikitext" inline> </syntaxhighlight>
names_only_as|...	<syntaxhighlight lang="wikitext" inline></syntaxhighlight>	<syntaxhighlight lang="wikitext" inline> </syntaxhighlight>
values_only_as|...	<syntaxhighlight lang="wikitext" inline></syntaxhighlight>	<syntaxhighlight lang="wikitext" inline> </syntaxhighlight>
blindly	<syntaxhighlight lang="wikitext" inline></syntaxhighlight>	<syntaxhighlight lang="wikitext" inline> </syntaxhighlight>

If the call style flags argument is omitted it defaults to values_only.

Note: All arguments passed to this modifier except the mapping_by_calling modifier name itself, the template name, the call style flag, the let keyword, the passed parameter names, and the number of additional parameters will not be trimmed of their leading and trailing spaces.

mapping_by_invoking

Brief

Map all parameter values, replacing their content with the text returned by a given module function repeatedly invoked with at least one argument (the parameter's value)

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This modifier (temporarily) changes the content of the parameters the current template is being called with, replacing each of them with the text returned by a custom module function. The latter will be repeatedly called with at least one argument as first sequential argument: the parameter's value.

It is possible to pass the parameter's value as a different argument, or pass the parameter's name as well, by specifying a call style flag immediately after the function name (see mapping_by_calling for the list of possible flags). If omitted, the call style flags argument defaults to values_only.

If the call style flag or (if omitted) the function name is followed by one or more groups of three arguments led by the let keyword (i.e. let|name|value), these will be passed to the mapping module function.

If the last group of three arguments or (if omitted) the call style flag or (if omitted) the function name is followed by a number, this will be parsed as the amount of positional parameters to add. These will always follow the current parameter's name and/or value if any of the latter are passed using a numeric name greater than zero.

In case of collisions, the arguments assigned via the let keyword will be given precedence over everything else.

For instance, before listing all parameters,

<syntaxhighlight lang="wikitext"></syntaxhighlight>

will replace each value with the expansion of <syntaxhighlight lang="wikitext" inline></syntaxhighlight> (where VALUE indicates each different value).

On the other hand,

<syntaxhighlight lang="wikitext"></syntaxhighlight>

will do the same, but using the expansion of <syntaxhighlight lang="wikitext" inline></syntaxhighlight> (where NAME and VALUE indicate each different name and value).

Note: All arguments passed to this modifier except the mapping_by_invoking modifier name itself, the module name, the function name, the call style flag, the let keyword, the passed parameter names, and the number of additional arguments will not be trimmed of their leading and trailing spaces.

mapping_by_magic

Brief

Map all parameter values, replacing their content with the expansion of a given parser function repeatedly called with at least one argument (the parameter's value)

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This modifier (temporarily) changes the content of the parameters the current template is being called with, replacing each of them with the text returned by a parser function. The latter will be repeatedly called with at least one argument as first sequential argument: the parameter's value.

It is possible to pass the parameter's value as a different argument, or pass the parameter's name as well, by specifying a call style flag immediately after the parser function name (see mapping_by_calling for the list of possible flags). If omitted, the call style flags argument defaults to values_only.

If the call style flag or (if omitted) the template name is followed by one or more groups of three arguments led by the let keyword (i.e. let|name|value), these will be passed to the parser function.

If the last group of three arguments or (if omitted) the call style flag or (if omitted) the template name is followed by a number, this will be parsed as the amount of positional arguments to add. These will always follow the current parameter's name and/or value if any of the latter are passed using a numeric name greater than zero.

In case of collisions, the arguments assigned via the let keyword will be given precedence over everything else.

For instance, before listing all parameters,

<syntaxhighlight lang="wikitext"></syntaxhighlight>

will replace each value with the expansion of <syntaxhighlight lang="wikitext" inline>VALUE</syntaxhighlight> (where VALUE indicates each different value).

On the other hand,

<syntaxhighlight lang="wikitext"></syntaxhighlight>

will do the same, but using the expansion of <syntaxhighlight lang="wikitext" inline>They are many</syntaxhighlight> (where NAME and VALUE indicate each different name and value).

Note: All arguments passed to this modifier except the mapping_by_magic modifier name itself, the parser function's name, the call style flag, the let keyword, the passed parameter names, and the number of additional arguments will not be trimmed of their leading and trailing spaces.

mapping_by_replacing

Brief

Map all parameter values performing string substitutions

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This modifier (temporarily) changes the content of the parameters the current template is being called with, replacing each of them with the result of a string substitution. Its syntax is very simlar to {{}}.

Internally the modifier uses Lua's string.gsub() function to perform substitutions; therefore, unless a plain flag is set, please use the same syntax of Lua patterns. The plain flag can be either plain or strict or omitted. When omitted it is assumed that the target string is a Lua pattern. The difference between plain and strict is that the latter also requires that the lengths match (this happens only when the two strings are 100% identical). In strict mode the replace argument will not accept directives (e.g. %0, %1, etc.). In order to facilitate wikitext scripting in the plain flag argument, the pattern keyword is available too, equivalent to omitting the argument.

The count argument prescribes how many substitutions will be performed at most. If blank or omitted, all matches found will be substituted.

This modifier uses string.gsub() for performance reasons; if you need to use mw.ustring.gsub() instead, you will need to invoke the replace function from Module:String via ...|mapping_by_invoking|string|replace|....

The following table shows examples of equivalent instructions. Please be aware that invoking mw.ustring.gsub() can be much slower.

string.gsub()	mw.ustring.gsub() (via Module:String)
...|mapping_by_replacing|target|replace|...	...|mapping_by_invoking|string|replace|4|target|replace||false|...
...|mapping_by_replacing|target|replace|count|...	...|mapping_by_invoking|string|replace|4|target|replace|count|false|...
...|mapping_by_replacing|target|replace|plain|...	...|mapping_by_invoking|string|replace|2|target|replace|... or, equivalently, ...|mapping_by_invoking|string|replace|4|target|replace||true|...
...|mapping_by_replacing|target|replace|count|plain|...	...|mapping_by_invoking|string|replace|3|target|replace|count|... or, equivalently, ...|mapping_by_invoking|string|replace|4|target|replace|count|true|...

There is not a corresponding translation for the strict flag in Module:String. However, as it goes with the plain flag, in that case you won't need mw.ustring.gsub() in the first place.

For example,

<syntaxhighlight lang="wikitext">...|mapping_by_renaming|foo|bar|1|...</syntaxhighlight>

will be equivalent to writing

<syntaxhighlight lang="wikitext">...|mapping_by_invoking|string|replace|4|foo|bar|1|false|...</syntaxhighlight>

The first syntax, however, will be less computationally expensive.

At {{./doc/examples/informal tablebox}} you can find an example on how to exploit this function to create "informal" infoboxes.

Note: The target and replace arguments passed to this modifier will not be trimmed of their leading and trailing spaces. The or, plain, strict and pattern keywords, the count argument, and the mapping_by_replacing modifier name itself, however, will be trimmed of their surrounding spaces.

mapping_by_mixing

Brief

Map all parameter values replacing their current values with the expansion of a custom string containing the $# and $@ placeholders

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This modifier (temporarily) changes the content of the parameters the current template is being called with, replacing each of them with the expansion of a custom string that expects the same syntax as the for_each function.

For instance, the following code will wrap all parameter values in quotes

<syntaxhighlight lang="wikitext">...|mapping_by_mixing|"$@"|...</syntaxhighlight>

whereas the following code will replace all values with the string [NAME::VALUE], where NAME and VALUE are each parameter's name and value:

<syntaxhighlight lang="wikitext">...|mapping_by_mixing|[$#::$@]|...</syntaxhighlight>

Note: Both the mixing string argument and the mapping_by_mixing modifier name itself will be trimmed of their surrounding spaces.

renaming_to_lowercase

Brief

Convert all parameter names to lower case

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This modifier does not take arguments besides the name of the function that will follow.

This modifier converts all parameter names to lower case. It is identical to writing ...|renaming_by_magic|lc|..., but without the burden of calling a parser function.

Note: In case of collisions between identical names, only one parameter, randomly chosen, will be left for a given name.

renaming_to_uppercase

Brief

Convert all parameter names to upper case

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This modifier does not take arguments besides the name of the function that will follow.

This modifier converts all parameter names to upper case. It is identical to writing ...|renaming_by_magic|uc|..., but without the burden of calling a parser function.

Note: In case of collisions between identical names, only one parameter, randomly chosen, will be left for a given name.

renaming_to_sequence

Brief

Rename all parameter names using sequential integers and possibly following a sort order

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This modifier renames all parameter names using increasing sequential integers, possibly following a given sort order.

The sort order optional flag specifies what sort order must be followed. Possible values are alphabetically, naturally (for natural sort order) and without_sorting. When omitted it defaults to without_sorting.

Wikitext:

<syntaxhighlight lang="wikitext"></syntaxhighlight>

Effect:

Wikitext:

<syntaxhighlight lang="wikitext"></syntaxhighlight>

Effect:

Note: The renaming_to_sequence modifier name and the sort order argument will be trimmed of their surrounding spaces.

renaming_by_calling

Brief

Rename all parameters, replacing their former names with the expansion of a given template repeatedly called with at least one parameter (the parameter's former name)

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This modifier works similarly to mapping_by_calling, but instead of replacing parameters' values it renames the parameters themselves. Care must be used knowing that if a new name collides with another new name one of the two parameters will be removed without knowing which one. New names and old names do not create collisions. If a name is returned identical it will be considered as "unchanged" and in case of conflicts the renamed one will prevail. Possible leading and trailing spaces in the new names are always stripped. Here, if omitted, the call style flags argument defaults to names_only.

For instance, the following example uses {{2x}} to rename all incoming parameters by doubling their names:

<syntaxhighlight lang="wikitext"></syntaxhighlight>

Same, but adding a hyphen in between:

<syntaxhighlight lang="wikitext"></syntaxhighlight>

The following example calls the {{P1}} template to rename all parameters using their value as their new name:

<syntaxhighlight lang="wikitext"></syntaxhighlight>

This modifier can be particularly useful for sanitizing parameter names (e.g. collapsing several spaces into single spaces, changing the letter case, and so on).

Note: All arguments passed to this modifier except the renaming_by_calling modifier name itself, the template name, the call style flag, the let keyword, the passed parameter names, and the number of additional arguments will not be trimmed of their leading and trailing spaces.

renaming_by_invoking

Brief

Rename all parameters, replacing their former names with the text returned by a given module function repeatedly called with at least one argument (the parameter's former name)

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This modifier works similarly to mapping_by_invoking, but instead of replacing parameters' values it renames the parameters themselves. Care must be used knowing that if a new name collides with another new name one of the two parameters will be removed without knowing which one. New names and old names do not create collisions. If a name is returned identical it will be considered as "unchanged" and in case of conflicts the renamed one will prevail. Possible leading and trailing spaces in the new names are always stripped. Here, if omitted, the call style flags argument defaults to names_only.

For instance, the following example uses {{}} to rename all parameters of type |a=, |b=, … |z= into |aaa=, |bbb= … |zzz=:

<syntaxhighlight lang="wikitext"></syntaxhighlight>

Note: All arguments passed to this modifier except the renaming_by_invoking modifier name itself, the module name, the function name, the call style flag, the let keyword, the passed parameter names, and the number of additional arguments will not be trimmed of their leading and trailing spaces.

renaming_by_magic

Brief

Rename all parameters, replacing their former names with the text returned by a given parser function repeatedly called with at least one argument (the parameter's former name)

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This modifier works similarly to mapping_by_magic, but instead of replacing parameters' values it renames the parameters themselves. Care must be used knowing that if a new name collides with another new name one of the two parameters will be removed without knowing which one. New names and old names do not create collisions. If a name is returned identical it will be considered as "unchanged" and in case of conflicts the renamed one will prevail. Possible leading and trailing spaces in the new names are always stripped. Here, if omitted, the call style flags argument defaults to names_only.

For instance, the following example uses {{#expr}} to transform all numeric parameters into even numbers (you can replace the expression %0 * 2 with any other expression):

<syntaxhighlight lang="wikitext"></syntaxhighlight>

An example that uses this function with the {{REVISIONTIMESTAMP}} magic word is available at {{./doc/examples/watchlist}}.

Note: All arguments passed to this modifier except the renaming_by_magic modifier name itself, the parser function name, the call style flag, the let keyword, the passed parameter names, and the number of additional arguments will not be trimmed of their leading and trailing spaces.

renaming_by_replacing

Brief

Rename all parameters, replacing their former names with the text returned by a string substitutions

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This modifier works similarly to mapping_by_replacing, but instead of replacing parameters' values it renames the parameters themselves. Care must be used knowing that if a new name collides with another new name one of the two parameters will be removed without knowing which one. New names and old names do not create collisions. If a name is returned identical it will be considered as "unchanged" and in case of conflicts the renamed one will prevail. Possible leading and trailing spaces in the new names are always stripped (however they are not stripped while searching for the name to replace).

Since there can be only one parameter name that matches exactly a literal string, when used with the strict flag this modifier directly accesses the requested key without looping through the entire list of parameters (so it will be much faster).

For instance, the following example renames all parameters of type |arg1=, |arg2=, … |argN= into |1=, |2= … |N=, thus creating a novel sequence:

<syntaxhighlight lang="wikitext"></syntaxhighlight>

This modifier can be particularly useful for sanitizing parameter names (e.g. collapsing several spaces into single spaces, changing the letter case, and so on).

For performance reasons this modifier uses string.gsub(); if you need to use mw.ustring.gsub() instead, you will need to invoke the replace function from Module:String via ...|renaming_by_invoking|string|replace|....

The following table shows examples of equivalent instructions. Please be aware that invoking mw.ustring.gsub() can be much slower.

string.gsub()	mw.ustring.gsub() (via Module:String)
...|renaming_by_replacing|target|replace|...	...|renaming_by_invoking|string|replace|4|target|replace||false|...
...|renaming_by_replacing|target|replace|count|...	...|renaming_by_invoking|string|replace|4|target|replace|count|false|...
...|renaming_by_replacing|target|replace|plain|...	...|renaming_by_invoking|string|replace|2|target|replace|... or, equivalently, ...|renaming_by_invoking|string|replace|4|target|replace||true|...
...|renaming_by_replacing|target|replace|count|plain|...	...|renaming_by_invoking|string|replace|3|target|replace|count|... or, equivalently, ...|renaming_by_invoking|string|replace|4|target|replace|count|true|...

There is not a corresponding translation for the strict flag in Module:String. However, as it goes with the plain flag, in that case you won't need mw.ustring.gsub() in the first place.

Note: The target and replace arguments passed to this modifier will not be trimmed of their leading and trailing spaces. The or, plain, strict and pattern keywords, the count argument, and the mapping_by_replacing modifier name itself, however, will be trimmed of their surrounding spaces.

renaming_by_mixing

Brief

Rename all parameters, replacing their former names with the expansion of a custom string containing the $# and $@ placeholders

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This modifier (temporarily) changes the content of the parameters the current template is being called with, replacing each of them with the expansion of a custom string that expects the same syntax as the for_each function.

For instance, the following code will wrap all parameter names in quotes

<syntaxhighlight lang="wikitext">...|renaming_by_mixing|"$#"|...</syntaxhighlight>

whereas the following code will replace all parameter names with the string [NAME::VALUE], where NAME and VALUE are each parameter's name and value:

<syntaxhighlight lang="wikitext">...|renaming_by_mixing|[$#::$@]|...</syntaxhighlight>

Note: The mixing string argument passed to this modifier will not be trimmed of its leading and trailing spaces. The renaming_by_mixing modifier name itself, however, will be trimmed of their surrounding spaces.

grouping_by_calling

Brief

Group the parameters that have the same numeric suffix into novel parameters, whose names will be numbers and whose values will be decided by a custom template

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This is the piping version of call_for_each_group. This means that after calling this modifier the old parameters will be (temporarily) gone and the only parameters left will be novel parameters whose names will be numbers (or an empty string if parameters without a numeric suffix were present) and whose content will be decided by a custom template.

Like other modifiers in the mapping_* and renaming_* family, it is possible to impose own parameters on the callback template by using the syntax ...|[let]|[...]|[number of additional arguments]|[argument 1]|[argument 2]|[...]|[argument N]|.... Unlike the other mapping_* and renaming_* modifiers, however (but like call_for_each_group), sequential parameters here will not be prepended, but will replace possible parsed parameters.

And so, writing

<syntaxhighlight lang="wikitext"></syntaxhighlight>

is identical to writing

<syntaxhighlight lang="wikitext"></syntaxhighlight>

In the example above the main difference will be that the first solution will allow to pass the newly grouped parameters at once to another template or module (via concat_and_call or concat_and_invoke) or, if needed, perform further fine-tuning operations concerning the new parameters.

Please refer to the documentation of call_for_each_group for further information on the parameters passed to the callback template.

Note: All arguments passed to this modifier except the grouping_by_calling modifier name itself, the template name, the let keyword, the passed parameter names, and the number of additional parameters will not be trimmed of their leading and trailing spaces.

parsing

Brief

Create new parameters by parsing a parameter string

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This modifier allows to add an infinity of new parameters by using a parameter string. By default this expects | as separator between parameters and = as separator between keys and values, but it is possible to specify other strings or patterns. The parsed parameters will overwrite existing parameters of the same name. For this reason, the new directive often accompanies this modifier.

Examples:

• <syntaxhighlight lang="wikitext" inline></syntaxhighlight>

  ↳

• <syntaxhighlight lang="wikitext" inline></syntaxhighlight>

  ↳

• <syntaxhighlight lang="wikitext" inline></syntaxhighlight>

  ↳

The trim flag argument can be placed in any position after the string to parse (not necessarily in second position) and can have one of the following values: trim_none, trim_named, trim_positional, trim_all. If omitted, it defaults to trim_named.

The iteration delimiter setter can be placed in any position after the string to parse (not necessarily in third position), must be immediately followed by a user-given string, and can be either splitter_string or splitter_pattern. If omitted, the two arguments default to splitter_string|{{!}}. If the custom string is empty (but not if it is blank but not empty) the string to parse will be assumed not to have any iteration delimiters (this will result in one single parameter being parsed).

The key-value delimiter setter can be placed in any position after the string to parse (not necessarily in fifth position), must be immediately followed by a user-given string, and can be either setter_string or setter_pattern. If omitted, the two arguments default to setter_string|{{=}}. If the custom string is empty (but not if it is blank but not empty) the string to parse will be assumed not to have any key-value delimiters (this will result in a sequence-only list of parameters being parsed).

Possible options

Setting a trim flag	Setting an iteration delimiter	Setting a key-value delimiter
trim_none trim_named trim_positional trim_all	splitter_string|... splitter_pattern|...	setter_string|... setter_pattern|...

Note: All arguments passed to this modifier except the parsing modifier name itself, the trim flag, iteration delimiter setter and key-value delimiter setter arguments will not be trimmed of their leading and trailing spaces.

reinterpreting

Brief

Use the content of a parameter as a parameter string to parse, after removing the parameter itself

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This modifier works exactly like parsing, but takes the content of a disposable parameter as input. See there for further information. The parameter passed to this modifier will be immediately deleted. The parsed parameters will overwrite existing parameters of the same name.

Example:

<syntaxhighlight lang="wikitext"></syntaxhighlight>

An example that shows how to use this function to transclude a custom template with custom parameters is available at {{./doc/examples/constructed transclusion}}.

Note: All arguments passed to this modifier except the reinterpreting modifier name itself, the parameter name, the trim flag, iteration delimiter setter and key-value delimiter setter arguments will not be trimmed of their leading and trailing spaces.

mixing_names_and_values

Brief

Rewrite all parameters, replacing names and values with the expansion of two custom strings containing the $# and $@ placeholders

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This modifier (temporarily) changes names and values of the parameters the current template is being called with, replacing each of them with the expansion of two custom strings that expect the same syntax as the for_each function.

For instance, the following code will wrap all parameter names and values in quotes

<syntaxhighlight lang="wikitext">...|mixing_names_and_values|"$#"|"$@"|...</syntaxhighlight>

whereas the following code will replace all names with the string VALUE/NAME and all values with the string [NAME::VALUE], where NAME and VALUE are each parameter's name and value:

<syntaxhighlight lang="wikitext">...|mixing_names_and_values|$@/$#|[$#::$@]|...</syntaxhighlight>

Note: The value mixing string argument passed to this modifier will not be trimmed of its leading and trailing spaces. The name mixing string argument and mixing_names_and_values modifier name itself, however, will be trimmed of their surrounding spaces.

combining

Brief

Combine all parameter names and values into a single parameter, possibly using a sort order and glue strings

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This modifier combines all parameter names and values into a single new parameter (whose name can be identical to that of a pre-existing parameter). It can be broadly considered as a “modifier version” of the list function.

The new parameter name argument specifies the name of the new parameter that must be created.

The sort order optional flag argument specifies a sort order. Possible values are alphabetically, naturally (for natural sort order) and without_sorting. When omitted it defaults to without_sorting.

The setting directives argument is identical to the first argument of the setting modifier, and accordingly is followed by a variable number of arguments (up to seven—see setting for more information). Differently than in setting, here the setting directives argument can be left empty (but not omitted).

For a similar modifier that combines only values and omits parameter names, see the combining_values modifier.

Wikitext:

<syntaxhighlight lang="wikitext"></syntaxhighlight>

Effect:

Wikitext:

<syntaxhighlight lang="wikitext"></syntaxhighlight>

Effect:

Wikitext:

<syntaxhighlight lang="wikitext"></syntaxhighlight>

Effect:

Note: The combining modifier name, the new parameter name argument and the sort order argument will be trimmed of their surrounding spaces. The setting directives argument will be stripped of all space characters, including internal spaces. All other arguments passed to this modifier will be parsed verbatim (i.e. leading and trailing spaces will not be removed).

combining_values

Brief

Combine all parameter names and values into a single parameter, possibly using a sort order and glue strings

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This modifier combines all parameter values into a single new parameter (whose name can be identical to that of a pre-existing parameter). It can be broadly considered as a “modifier version” of the list_values function. Its syntax is identical to that of combining; see there for more information.

Note: The combining_values modifier name, the new parameter name argument and the sort order argument will be trimmed of their surrounding spaces. The setting directives argument will be stripped of all space characters, including internal spaces. All other arguments passed to this modifier will be parsed verbatim (i.e. leading and trailing spaces will not be removed).

combining_by_calling

Brief

Pass all current parameters to a custom template and save the returned output as a new parameter

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This is the piping version of concat_and_call. This means that after calling this modifier the old parameters will be (temporarily) gone and the only parameter left will be what is specified in the new parameter name argument.

Since after using this modifier all parameters will be grouped into one single parameter, to pass additional parameters to the callback template you can safely use imposing or parsing.

For instance, using ./testcases/tdummy echo sb as callback template, a template named <syntaxhighlight lang="wikitext" inline> </syntaxhighlight> with the following content,

<syntaxhighlight lang="wikitext"></syntaxhighlight>

when transcluded as <syntaxhighlight lang="wikitext" inline> </syntaxhighlight> will produce

snapshotting

Brief

Push a copy of the current parameter list to the queue of parameter lists

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This modifier does not take arguments besides the name of the function that will follow.

This module has a stacking mechanism that allows to isolate groups of parameters, work separately on them, and then merge them back to the original stack. The modifiers dedicated to this mechanism are:

• snapshotting
• remembering
• entering_substack
• pulling
• detaching_substack
• dropping_substack
• leaving_substack
• merging_substack
• flushing

Every time the snapshotting modifier is used, the current list of parameters (together with their values) will be copied and added to a queue. When the entering_substack modifier is used, the list of parameters on top of the queue will temporarily become the current parameters, and all other modifiers will affect only this substack. After completing the job, the merging_substack will merge the current substack to the parent stack.

If no parameter lists have been snapshotted before calling entering_substack, the latter will automatically make a snapshot of the current parameters. Once inside a substack, it is possible to enter a subsubstack using the same machinery.

The detaching_substack modifier erases the current parameters from the parent stack, allowing the current stack to rename its parameters freely and merge them back to the parent stack, renamed.

It is possible to leave a substack without merging it to the parent by using the leaving_substack modifier. In this case, at some point it will be necessary to call flushing in order to merge the stack previously left unmerged. Alternatively, it will be possible to enter it again by calling entering_substack, and finally merge it via merging_substack. It is also possible to drop and discard a substack completely via dropping_substack

An example will probably clarify the mechanism better than anything else:

<syntaxhighlight lang="wikitext"></syntaxhighlight>

The code above will result in:

A more advanced example is available at {{./doc/examples/universal page list}}.

remembering

Brief

Push a copy of the original (unmodified) parameter list to the queue of snapshots

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This modifier does not take arguments besides the name of the function that will follow.

This modifier is somewhat similar to snapshotting, except that it retrieves the parameters that were originally passed to the calling template before being affected by the module's modifiers. The modifier works also after the new directive. See snapshotting for more information on the stacking mechanism.

entering_substack

Brief

Enter the first stack in the queue of parameter lists, or copy the current parameters into a substack if the queue is empty

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This modifier does not take arguments besides the name of the function that will follow.

See snapshotting for more information on the stacking mechanism. Once in a substack, it is possible to go back to the parent stack using three different modifiers: merging_substack, leaving_substack and dropping_substack.

pulling

Brief

Pull a single parameter from the parent stack or from the stack of the original parameters

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

See snapshotting for more information on the stacking mechanism. If this modifer is not used in a substack, the parameter will be pulled from the original (unmodified) parameter list.

detaching_substack

Brief

Remove from the parent stack the parameters that are present in the current stack

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This modifier does not take arguments besides the name of the function that will follow.

This modifer can only be used in a substack. See snapshotting for more information on the stacking mechanism.

dropping_substack

Brief

Go back to the parent stack dropping the current substack

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This modifier does not take arguments besides the name of the function that will follow.

This modifer can only be used in a substack. See snapshotting for more information on the stacking mechanism.

leaving_substack

Brief

Leave the current substack without merging it, and return to the parent stack

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This modifier does not take arguments besides the name of the function that will follow.

This modifer can only be used in a substack. See snapshotting for more information on the stacking mechanism.

See flushing for an example of how to use this modifier.

merging_substack

Brief

Leave the current stack after merging it with the parent stack, then return to the latter

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This modifier does not take arguments besides the name of the function that will follow.

This modifer can only be used in a substack. See snapshotting for more information on the stacking mechanism.

flushing

Brief

Merge the first stack in the queue of snapshotted parameters with the current stack.

Syntax

<syntaxhighlight lang="wikitext" inline></syntaxhighlight>

This modifier does not take arguments besides the name of the function that will follow.

This modifier is used in conjunction with either leaving_substack or snapshotting. See snapshotting for more information on the stacking mechanism.

In the following wrapper of an <syntaxhighlight lang="wikitext" inline> </syntaxhighlight>, the three parameters |1=, |2=, and |3= are used as aliases for |title=, |author=, and |language= respectively. The flushing modifier ensures that in case both are present, the named alias will have the precedence over the positional alias.

<syntaxhighlight lang="wikitext"></syntaxhighlight>

new

Brief

Get rid of all the incoming parameters and create a new (empty) parameter stack

Syntax

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This modifier does not take arguments besides the name of the function that will follow.

This modifier can only appear in first position, or if substacks are present, immediately after the entering_substack directive. When in first position, its main purpose is that of extending the facilities offered by this module (e.g. mapping_by_replacing, with_value_matching, etc.) to custom lists of strings, independently of the incoming parameters. When inside a stack, it signals that the snapshot of the current parameters must be ignored for that stack. The existence of the new modifier also facilitates debugging the module.

The newly created parameter stack can be populated via parsing, imposing or providing. The incoming parameters can always be retrieved back using the remembering and pulling modifiers.

Examples:

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Subpages

• Module:Params/ChangeLog – Record of the most important changes in the module's code
• Module:Params/testcases – Testing the module's capabilities
• Module:Params/doc/examples – Some of the examples mentioned in this documentation

The complete list of subpages is available here.

See also

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