「ヘルプ:Categories/ja」を編集中

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Categories, a software feature of MediaWiki, provide automatic indexes that are useful as tables of contents.

MediaWikiではページやファイルを'''カテゴリ'''に分類することができます。これは '''{{ns:category}}''' タグをページに追加することで行います。このタグをページに書き込むと、ページの最下部にカテゴリへのリンクができます。リンク先のページでは、そのカテゴリに属するすべてのページの一覧が表示されますので、関連する項目を探すのに便利です。

== Summary ==
Each of the pages in the '''Category''' [[Help:Namespace|namespace]] represents a so-called '''category''', a grouping of related pages, and contains an index for the pages of its category. For example, this page belongs to "[[:Category:Help]]". If you open the "[[:Category:Help]]" page, you will see a link to this page there.

When a page belongs to one or more categories, these categories appear at the bottom of the page (or in the upper-right corner, depending on the [[Help:Preferences|skin]] being used).

The category pages themselves contain 2 parts :
* at their beginning, an optional part may contain text that can be edited, like any other page,
* at their end, an ever present, automatically generated, alphabetical list of all pages in that category, in the form of links. (In fact, in ASCII order. See [[Help:Special page]]).

To assign a category to a page, simply add the link "<nowiki>[[</nowiki>Category:''Category name'']]" to the page's wikitext. The usual place to add it is at the bottom of the page.

To link a category page within a page as a normal wiki link (without adding the page to the category), prefix the link name with a colon.  For example: <nowiki>[[</nowiki>:Category:Not in this category]]

New categories can be [[Help:Starting a new page|created]] before assigning any page to it, in the same way as any other regular page.

Individual wikis may have their own top-level categories, such as [[wikipedia:Category:Contents|Category:Contents]] in Wikipedia.

For a complete list of all categories which have at least one page, see [[Special:Categories]].

For a complete list of all created/edited categories, including the ones that don't have any page, see [[Special:Allpages/Category:]] (note the colon at the end).

== ページをカテゴリに追加する ==
ページをカテゴリに追加するためには、ページの編集テキストを開いて、以下のように書くだけです。(where '''''Name''''' is the name of the category you want to add it to)

 <nowiki>[[</nowiki>{{ns:category}}:''カテゴリ名'']]

''カテゴリ名''には追加したいカテゴリの名前が入ります。{{ns:category}} タグはいくつでもページに追加でき、各カテゴリでそれぞれにそのページが一覧に含まれるようになります。{{ns:category}} タグは編集テキストのどこに追加しても有効ですが、編集しやすいようにページの一番最後に追加するのが一般的です。

On a categorised page, categories are displayed in the Categories: box strictly in the order they appear in the wikitext. 

If $wgUseCategoryBrowser is set to true, under the first list each category is listed again, [[wikipedia:breadcrumb (navigation)|breadcrumb]]-style, with all its parent categories, sorted alphabetically. (At least in MediaWiki 1.18.2) if a category is a subcategory of more than one parent, both hierarchies will be listed, but the tagged category will be stripped off all but one of these. This creates the potential for what appear to be duplicate entries if a category with multiple parents ''and'' one of its parents are both tagged on a page. For example suppose Maryanne is a subcategory of both Mary and Anne. If a page tags categories Maryanne and Anne then the Category breadcrumbs will show
 Anne 
 Anne
 Mary -> Maryanne

"Anne" appears to be duplicated, but what is meant is
 Anne 
 Anne -> Maryanne
 Mary -> Maryanne

This is probably a bug, and has been reported in [https://bugzilla.wikimedia.org/show_bug.cgi?id=33614 Bug 33614].

=== ソートキー ===
By default, a page is sorted within a category under the first letter of its name — ''without the namespace''. Also, MediaWiki groups accented characters separately from their unaccented version, so pages starting by À, Á, Ä, will be listed under separate headings, instead of under heading A. (If you have shell access, these defaults can be changed using [[Manual:$wgCategoryCollation|$wgCategoryCollation]].)

A ''sort key'' specifies under which letter heading, and where in the category list, the page will appear. You can add a sort key by placing it inside the tag after a pipe character. For example, the tag below will add the page under heading "S".

 <nowiki>[[</nowiki>{{ns:category}}:'''''Name'''''|'''''Sort''''']]

ソートキーは大文字小文字を区別し、また空白文字もソートキーとして認識されます。カテゴリ内の各セクションの順番はUnicodeの順番に従います。The sort key does not change the page title displayed in the category.

See [[Help:Sorting]] for further information on category sorting.

== カテゴリページの作成 ==
Categories exist even if their page has not been created, but these categories are isolated from others and serve little purpose for organization or navigation.

カテゴリは他のページと同じ方法で '''''Category:''''' 名前空間に作成できます（[[Help:Starting a new page/ja]]参照）。ただ、カテゴリ名の前に <code>{{ns:category}}:</code> を追加するだけです。

無駄な手間を生じさせないためにも、カテゴリを新規作成する前にウィキ内にあるカテゴリをよく調査した方がよいでしょう。[[Help:Navigation#Sidebar|サイドバー]]の「{{lcfirst:{{int:toolbox}}}}」にある「{{lcfirst:{{int:specialpages}}}}」のリンクからウィキ内の全カテゴリの一覧にアクセスできます。

他のページと異なり、カテゴリの改名（移動）はできません。改名が必要な場合、新しくカテゴリを作り直し、カテゴリに入れるページのカテゴリタグをすべて貼り替えなければなりません。この方法はカテゴリの履歴を失うことになり、カテゴリページに説明用テキストが多く含まれる場合にはあまりよくありません。

==カテゴリの階層の保守==   
Categories may belong to other categories in a hierarchy. Since category pages are much like any other page, a {{ns:category}} tag may be added to the bottom of a category page. 

It is a good idea to organize all categories into a hierarchy with a single top level category. The category structure can take the form of a tree with separate branches, but more often will have a graph structure. Generally, there should be a contiguous chain of parent-child links between each category and the top level category. 

==隠しカテゴリ==
The categories that a page is in are normally listed at the bottom of the page. 
In Mediawiki 1.13+,
a category can be hidden from this list by adding the [[Help:Magic words/ja|マジックワード]] "<code><nowiki>__HIDDENCAT__</nowiki></code>" to the category page. Hidden categories are not hidden from category pages ({{bugzilla|15550}}).

Users can choose to see hidden categories in a separate "{{int:hidden-categories}}" list, by checking "{{int:tog-showhiddencats}}" in the "{{int:prefs-rendering}}" section of [[Special:Preferences]].

Hidden categories are automatically added to [[:Category:{{mediawiki:hidden-category-category}}]]. This category is specified in the system message [[MediaWiki:Hidden-category-category]].

''関連項目:'' [[m:Help:Category#Hidden_categories|hidden categories]]

== カテゴリページにリンクする ==
カテゴリページにリンクをするには、冒頭にコロン（<code>:</code>）を挿入します (このコロンがないと、そのページがカテゴリに追加されます):

:<code><nowiki>[[</nowiki>:{{ns:category}}:Help]]</code> &rarr; '''[[:{{ns:category}}:Help]]''' 

リンクラベルに別のテキストを表示したい場合は、パイプのあとにリンクラベルを書きます:

:<code><nowiki>[[</nowiki>:{{ns:category}}:Help|Help category]]</code> &rarr; '''[[:{{ns:category}}:Help|Help category]]'''
 
カテゴリへの[[Help:Redirects/ja|リダイレクト]]にも冒頭のコロンをつけないと、そのリダイレクトページがカテゴリに含まれてしまいます。

==カテゴリのリダイレクト==
Like normal wiki pages, category pages can be redirected to other normal or category pages. ''However'', this is not recommended, as pages categorised in redirected categories do ''not'' get categorised in the target category ([[:bugzilla:3311]]). Some Wikimedia sites use a "category redirect" template to mark redirected categories, allowing manual or automated cleanup of pages categorised there.

==カテゴリの追跡==
Certain syntax issues, such as a broken image link, or too many expensive parser functions, can cause a page to be added to a tracking category. See [[Help:Tracking categories]] for details.

==関連項目==
* [[:Category:Category extensions/ja]]

{{Languages}}
[[Category:Help/ja|Categories]]
[[Category:Category/ja]]