CachingFilter

The CachingFilter is similar to the ELMappingFilter but instead of storing the data attributes or control values in the repository of the entity it creates a new ObjectMap and stores it under a given name in the specified repository. Thus, it is similar to the CollectingFilter with the difference of storing complete ObjectMaps instead of single values.

Configuration

Name	Type, usage constraints, defaults	Description
repository	required: paraVal default: none type: string	The repository name used to store the cache objects.
cacheName	required: paraVal default: none type: string	The name under which the ObjectMap is stored in the repository.

Example

The following example shows how the CachingFilter can be used to store user data in a cache:

<dataFilter type="CachingFilter">
<!-- the filter configuration -->
    <dp:paraVal name="repository" value="storage" />
    <dp:paraVal name="cacheName" value="#{in.user.id}" />
<!-- attribute created on the control object -->
    <dp:ctlVal name="id" value="#{in.user.id}"/>
    <dp:ctlVal name="name" value="#{in.user.name}"/>
</dataFilter>

A filter of a subsequent entity “user” uses the cached users for filtering:

<dataFilter type="ELMappingFilter">
    <dp:paraVal name="skipwhen" value="#{ctx:hasKey(ctl.storage, in.user.uid)}" />
</dataFilter>

A filter of a subsequent entity “data” uses the cached users for data enrichment:

<dataFilter type="ELMappingFilter">
    <dp:attrVal name="name" value="#{in.storage[in.data.userId],name"/>
</dataFilter>

An entity uses the cached data as DataSource:

<dataSource type="BeanDataSource">
    <dp:paraVal name="bean" value="#{ctl.storage}"/>
</dataSource>