Editing Module:Labelled list hatnote/doc (section)

== Usage ==

===labelledList===
Invoking the <code>labelledList()</code> function is enough to implement most such templates:

<code><nowiki>{{#invoke:Labelled list hatnote|labelledList|Universal label}}</nowiki></code>

or

<code><nowiki>{{#invoke:Labelled list hatnote|labelledList|Singular label|Plural label}}</nowiki></code>

For example, providing "See also" instead of "Universal label" duplicates the functionality of {{tl|see also}}, while providing "Main article" and "Main articles" instead of "Singular label" and "Plural label" duplicates the (article namespace) functionality of {{tl|main}}.

If third and fourth labels are provided, they'll be used in the case where any of the target pages are outside the article namespace, so e.g. {{tl|main}} can be implemented thus:

<code><nowiki>{{#invoke:Labelled list hatnote|labelledList|Main article|Main articles|Main page|Main pages}}</nowiki></code>

===preprocessDisplays===
The <code>preprocessDisplays()</code> function takes a raw list of arguments and combines in any display arguments. For example, {{tlx|see also|1|<nowiki>l1=One</nowiki>}} initially has the arguments table <code><nowiki>{'1', ['l1'] = 'One'}</nowiki></code>; this table would combine those into the table <code><nowiki>{'1|One'}</nowiki></code>. It overrides manual piping (e.g. {{tlx|see also|<nowiki>1{{!}}2</nowiki>|<nowiki>l1=One</nowiki>}} → <code><nowiki>{'1|One'}</nowiki></code>) and compresses sparse arrays if a parameter is skipped or left empty.

Example: <syntaxhighlight lang="lua">
local mLabelledList = require('Module:Labelled list hatnote')
local pages = mLabelledList.preprocessDisplays(args)
</syntaxhighlight>

===_labelledList===
For modules that need to modify the functionality slightly while still using it, <code>_labelledList()</code> provides some flexibility. It takes three parameters:
# A pages list, preferably preprocessed and compressed by <code>preprocessDisplays</code>
# A labels table, where the first item is the singular or universal label, and the second either a plural label or a copy of the first.
# An options table, preferably containing:
#* a <code>template</code> string with the full title of the template. Defaults to the title of this module.
#* a <code>category</code> string (or nil) as taken by <code>makeWikitextError</code> from [[Module:Hatnote]], to optionally disable error categories
#* a <code>selfref</code> string (or nil) as taken by <code>_hatnote</code> to enable the selfref option

Example: <syntaxhighlight lang="lua">
local mLabelledList = require('Module:Labelled list hatnote')
return mLabelledList._labelledList(pages, labels, options)
</syntaxhighlight>