Property:Allows value

{{LangSwitch
| en = '''Allows value''' is a [[special property]] in [[Semantic MediaWiki]] with a built-in meaning: it lists one permissible value for a property.

You can use this special property with a property of any datatype to limit its possible values.
For example, the page for a ''Problem severity'' property might contain:
| ja = '''Allows value''' は [[Semantic MediaWiki (ja)|Semantic MediaWiki]] の [[special property (ja)|特別プロパティ]] として、次の意味があらかじめ設定されています: このプロパティは、プロパティの取り得る値を 1 つ列挙します。

この特別プロパティは、任意のデータ型のプロパティにおいてその取り得る値を制限するために使用できます。 例えば、''Problem severity'' （深刻度） プロパティページでは、以下のように記述されるでしょう:
}}

  <nowiki>[[allows value::Enhancement]],[[allows value::Trivial]],[[allows value::Minor]],
 [[allows value::Normal]],[[allows value::Major]],[[allows value::Critical]]</nowiki>

=== Ordered properties ===

Enumerating several ''Allows value'' does not put the possible values of a property in that order;  properties of [[Type:String]] will still sort in alphabetical order.  You can ensure alphabetical sort order is appropriate using a prefix, for example:
  <nowiki>[[allows value::a-Enhancement]],[[allows value::b-Trivial]], [[allows value::c-Minor]]...</nowiki>
and then you can [[Help:Semantic_search#Comparators|query]] for greater-than-or-equal or less-than-or-equal values, for example <nowiki>[[</nowiki>''property name''::<c-Minor]]

You can create a property of [[Type:Number]] and give it allowed values that are "pseudo-numbers", for example:
  <nowiki>[[Allows value::1 - Low]] [[Allows value::2 - Medium]] [[Allows value::2 - Middling]] ...</nowiki>
SMW's number datatype ignores the "''- description''" after the number.  This gives the set of properties a numerical order and lets you make two values equivalent.

[[Category:Special property|Allows value]]
[[Category:Semantic MediaWiki documentation]]