Help:Property change propagation

Property type change propagation
Activities and requirements while the change propagation is underway
Keywords
value annotation · type change · change propagation

Missing value assignments while type change propagation is underway

The change of a property's datatype will initiate a 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"Holds particular points in time vs. datatype "URL"Holds URIs, URNs and URLs) and value constraints and with it influences a property's fundamental specification therefore a 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 Semantic MediaWiki 3.0.0Released on 11 October 2018 and compatible with MW 1.27.0 - 1.31.x. 1. 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 special property "Subcategory of"Lets you explicitly indicate that one category is a subcategory of another).2

See also

• Help page on properties and types
• Help page on change propagation
• Help page on configuration parameter $smwgChangePropagationWatchlistSets the properties that are relevant for property change propagation
• Help page on configuration parameter $smwgChangePropagationProtectionSets whether property pages are protected from editing while a property change propagation is being processed
• Help page on special property "Change propagation"Holds the new property specification of a property or category page