View source for Help:Property change propagation

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[[File:property-type-change-missing-assignment.png|thumb|250px|Missing value assignments while type change propagation is underway]]
The '''change of a property's datatype''' will initiate a [[has keyword::change propagation]] process on all dependent entities that have a value assigned for the altered property and will temporary (after the change) appear with an unassigned value while the [[job queue]] is working its way through the backlog. Depending on the size and rate of executable jobs, the update may take a moment before all queries can display the newly assigned value.

The reason for this process is that each [[datatype]] is described by certain display characteristics (e.g {{DataType|Date}} vs. {{DataType|URL}}) and value constraints and with it influences a property's fundamental specification therefore a [[Help:Change propagation|change propagation]] ensures that an altered property notifies all entities with a value assignment in order to be updated in due time.

The approach on how changes are propagated has been revised with {{Release|3.0.0}} [[CiteRef::gh:smw:2494]]. This version also brought the tracking of changes to categories when their hierarchy structure is altered and hereby allows related entities to be reevaluated (see {{SpecialProperty|Subcategory of}}).[[CiteRef::gh:smw:2776]]

== See also ==
* Help page on [[Has parent page::Help:Properties and types|properties and types]] 
* Help page on [[Has parent page::Change propagation|change propagation]]
* Help page on {{Config|$smwgChangePropagationWatchlist}}
* Help page on {{Config|$smwgChangePropagationProtection}}
* Help page on {{SpecialProperty|Change propagation}}
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