View source for Template:CatAutoTOC/doc

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<!-- Please place categories where indicated at the bottom of this page and interwikis at Wikidata (see [[Wikipedia:Wikidata]]) -->
Adds a Table of Contents (TOC) to a category page if the category's size warrants it.

The size thresholds are:

# <= 100 pages → no TOC
# 101–1200 pages → {{tl|Category TOC}}
# > 1200 pages → {{tl|Large category TOC}}

==Usage==
<code><nowiki>{{CatAutoTOC}}</nowiki></code>

On category pages, <code><nowiki>{{CatAutoTOC}}</nowiki></code> can be placed wherever you want the TOC to be displayed.

On a category header template, it is best placed outside any <code><nowiki><includeonly></includeonly></nowiki></code> tags, so that the template is categorised as using CatAutoTOC.

=== Parameters ===
No parameters are needed.

However, the parameters available {{tl|Category TOC}} may be supplied, and if CatAutoTOC calls {{tl|Category TOC}}, those parameters will be passed on to {{tl|Category TOC}}.

So e.g. <code><nowiki>{{CatAutoTOC|align=center}}</nowiki></code> will:
# Have no effect if no TOC is generated
# Align to the center if {{tl|Category TOC}} is used
# Have no effect if {{tl|Large category TOC}} is used, because {{tl|Large category TOC}} accepts no parameters

== Tracking ==
<div style="display:block; float:right">{{CatAutoTOC stats}}</div>
Each page using this template is categorised in one of three tracking categories:
* [[:Category:CatAutoTOC generates no TOC]]
* [[:Category:CatAutoTOC generates standard Category TOC]]
* [[:Category:CatAutoTOC generates Large category TOC]]

Templates which transclude {{tl|CatAutoTOC}} are categorised in
* [[:Category:Templates using CatAutoTOC]]  (population: {{PAGESINCATEGORY:Templates using CatAutoTOC}})

... but only if the transclusion is outside any <code><nowiki><noinclude></noinclude></nowiki></code> tags

<small>{{Purge|''Purge this page to update the totals''}}</small>

== Bugs ==
This template uses the [[Help:Magic words|magic word]] <code><nowiki>{{PAGESINCATEGORY}}</nowiki></code> to count the number of pages in the category.  Unfortunately, this function can return wildly erroneous results on some categories which have had many pages added and removed.

This bug is well-known, and has been documented in several places since 2010, including:
* [[phab:T18036]]
* [[phab:T221795]]
* [[phab:T69196]]

In the overwhelming majority of categories, the count is recorded accurately enough to support use of this template.  However, there seemed to be some issue with <code><nowiki>{{PAGESINCATEGORY}}</nowiki></code> falsely returning zero in some cases.  This is tracked in:
* [[:Category:CatAutoTOC on pages where PAGESINCATEGORY returns zero]] (population: {{PAGESINCATEGORY:CatAutoTOC on pages where PAGESINCATEGORY returns zero}})

As of 19 April 2020, that problem seems to have been fixed by a small but cunning tweak[https://en.wikipedia.org/w/index.php?title=Template%3ACatAutoTOC&type=revision&diff=951919806&oldid=950933704] to how <code><nowiki>{{PAGESINCATEGORY}}</nowiki></code> is called.

The category ''should'' contain only pages labelled as "empty".
<small>{{Purge page|''Purge page to update totals''}}</small>

== See also ==
{{Category TOC see also}}

<includeonly>{{sandbox other||
<!-- Categories below this line, please; interwikis at Wikidata -->
[[Category:Category header templates]]
[[Category:Wikipedia category table of contents templates]]
}}</includeonly>