Package org.alfresco.repo.thumbnail.conditions

Class NodeEligibleForRethumbnailingEvaluator

java.lang.Object
org.alfresco.repo.action.CommonResourceAbstractBase
org.alfresco.repo.action.ParameterizedItemAbstractBase
org.alfresco.repo.action.evaluator.ActionConditionEvaluatorAbstractBase
org.alfresco.repo.thumbnail.conditions.NodeEligibleForRethumbnailingEvaluator
All Implemented Interfaces:
ActionConditionEvaluator, org.springframework.beans.factory.Aware, org.springframework.beans.factory.BeanNameAware
@Deprecated public class NodeEligibleForRethumbnailingEvaluator extends ActionConditionEvaluatorAbstractBase
Deprecated.
The thumbnails code is being moved out of the codebase and replaced by the new async RenditionService2 or other external libraries.
This action evaluator is specifically created for the Thumbnail Service. It is used to evaluate whether a ThumbnailDefinition should be executed - based on previous failed thumbnail attempts for that definition on that source node, as well as some configuration data.

The behaviour is as follows:

  • All content nodes are eligible for thumbnailing initially. Of course thumbnails can only ever be attempted for those content mime types that have at least one registered and active ContentTransformer.
  • If the first attempt to produce a thumbnail for a node fails, then it may be retried up to a maximum of system.thumbnail.retryCount times.
  • These initial retries to produce a thumbnail will occur not more often than every system.thumbnail.retryPeriod seconds and will use which ever content transformers the ContentService#getTransformer(String, String content service gives.
  • If a thumbnail is not successfully produced for a node after these attempts then it is considered to be a 'difficult' piece of content with respect to thumbnailing and the assumption is that a thumbnail may never be available for it. However, in order to allow for the possibility of software upgrades or similiar, which may make the content thumbnailable at a later date, further attempts will be made, but at a much reduced frequency.
  • Difficult pieces of content will not be attempted more often than every system.thumbnail.quietPeriod seconds.
  • The attempts to thumbnail difficult pieces of content can be disabled by setting system.thumbnail.quietPeriodRetriesEnabled to false.
At all times, thumbnails will be attempted when a user navigates to a page which needs to show the relevant thumbnail (lazy production).
Since:
3.5.0
Author:
Neil Mc Erlean.