Help:Property constraints portal/Format/tr

format constraint (Q21502404) specifies that values for a property should conform to a certain pattern.

For example, the value for GNIS Feature ID (P590) should always be a number with up to eight digits, without leading zeroes: [1-9][0-9]{0,7}.

The pattern is a regular expression, but the flavor varies: KrBot, which creates the database reports, uses PCRE; the WikibaseQualityConstraints extension, which powers the live constraint checks and Special:ConstraintReport, uses PCRE since August 2021 (having previously used java.util.regex); OpenRefine uses java.util.regex; other implementations may use something else to check regular expressions. The flavors are mostly, but not entirely compatible; for maximum compatibility with different constraint engines, it’s recommended to stick to the common subset of the flavors.

If no constraint scope (P4680) is specified, this constraint is checked everywhere.

Possible actions

There are several possible ways to address a violation of this constraint:

• The most likely case is that the value is malformed in some way. Often the fix is straightforward: add a missing prefix or remove one that should be implicit, add punctuation (e. g. add hyphens to an ISBN), fix capitalization, etc.
• It’s possible that the value is correct, but does not belong to this property, and that it should be moved to a statement for a different property (e. g. ISBN-13 (P212) to ISBN-10 (P957)).
• It’s possible that the identifier has expanded its range and the regex needs to be adapted (e.g. an identifier now uses up to 15 digits and not 10 as when it was first defined).
• It’s possible that the item is a rare, but legitimate exception to the constraint, and nothing should be done.

Parametreler

This constraint has one mandatory and one optional parameter:

format as a regular expression (P1793)

Contains the format / pattern. Must contain exactly one value (no value Help or unknown value Help is not permitted), which must be a valid regular expression. Note that, at least for WikibaseQualityConstraints, the pattern should not be escaped (e.g. / should not be escaped as \/). The pattern is matched against the full value, so it’s generally not necessary to include ^ or $ in the pattern: \d+ and ^\d+$ both allow and disallow the same values, and the shorter form is preferred.

syntax clarification (P2916)

Contains a human-readable description of the pattern. Can be specified several times in different languages.

Örnekler

Örnek 1

Values for image (P18) should end with certain file extension like .jpg or .png.

property constraint	format constraint edit format as a regular expression (?i).+\.(jpg|jpeg|png|svg|tif|tiff|gif|xcf) 0 references add reference
		add value

Example 2

Using syntax clarification (P2916) parameter for explaining the regular expression in human-readable text. For example, value of IPA transcription (P898) doesn't contain : (colon) or ' (apostrophe). Correct character is ː (length) or ˈ (stress). This regular expression is difficult to understand without explanation.

property constraint	format constraint edit format as a regular expression [^:]+ syntax clarification colon is not a valid IPA character, the correct character for a length mark is ː (English) 0 references add reference format constraint edit format as a regular expression [^']+ syntax clarification apostrophe is not a valid IPA character, the correct character for primary stress is ˈ (English) 0 references add reference
		add value

Şablonlar

When the constraint is set to the property, the following template is automatically displayed in the property talk page. The template is created by Module:Constraints using Template:Constraint, invoked from Template:Property documentation. Translations are defined at Module:i18n/constraints.

Format “(?i).+\.(jpg|jpeg|jpe|png|svg|tif|tiff|gif|xcf|pdf|djvu|webp)|”: value must be formatted using this pattern (PCRE syntax). (Help)

Exceptions are possible as rare values may exist. Exceptions can be specified using exception to constraint (P2303).
List of violations of this constraint: Database reports/Constraint violations/P18#Format, SPARQL

Listeler

Lists of properties which are set format constraint.

• Category:Properties with format constraints
• SPARQL query - click the execute button at the linked page to see the query result.