Difference between revisions of "Transformer (extension point)"

Revision as of 17:55, 13 May 2013

Identifier

ru.biosoft.access.transformer

Plugin

ru.biosoft.access

Registry

TransformerRegistry

Description

Transformer classes should be registered if you want transformed items to be compatible with GenericDataCollection.

Configuration Markup

<!ELEMENT transformer>
<!ATTLIST transformer
     inputClass        CDATA #REQUIRED
     outputClass       CDATA #REQUIRED
     transformerClass  CDATA #REQUIRED
>

inputClass

Fully-qualified name of input class accepted by transformer. Currently only FileDataElement and Entry are supported.

outputClass

Fully-qualified name of output class accepted by transformer. Must implement DataElement interface.

transformerClass

Fully-qualified name of the transformer class. Must implement Transformer interface. Transformer.getInputType() must return inputClass and Transformer.getOutputType() must return outputClass. In many cases it's easier to inherit AbstractTransformer class.

Example

<extension id="image file transformer" point="ru.biosoft.access.transformer"> 
   <transformer 
      inputClass="ru.biosoft.access.FileDataElement" 
      outputClass="ru.biosoft.access.ImageDataElement" 
      transformerClass="ru.biosoft.access.support.FileImageTransformer"/> 
</extension>

This extension allows ImageDataElement objects to be converted to FileDataElement and vice-versa via FileImageTransformer. Thanks to this extension you can put ImageDataElement objects to GenericDataCollection collections.