Package org.dspace.content.crosswalk

Class XSLTCrosswalk

java.lang.Object
org.dspace.core.SelfNamedPlugin
org.dspace.content.crosswalk.XSLTCrosswalk
All Implemented Interfaces:
NameAwarePlugin
Direct Known Subclasses:
XSLTDisseminationCrosswalk, XSLTIngestionCrosswalk
public abstract class XSLTCrosswalk extends SelfNamedPlugin
Configurable XSLT-driven Crosswalk

This is the superclass of the XSLT dissemination and submission crosswalks. These classes let you can create many different crosswalks between DSpace internal data and any XML without changing any code, just XSL transformation (XSLT) stylesheets. Each configured stylesheet appears as a new plugin name, although they all share the same plugin implementation class.

The XML transformation must produce (for submission) or expect (for dissemination) a document in DIM - DSpace Intermediate Metadata format. See http://wiki.dspace.org/DspaceIntermediateMetadata for details.

Configuration

Prepare your DSpace configuration as follows:

A submission crosswalk is described by a configuration key like 

  crosswalk.submission.PluginName.stylesheet = path
The alias names the Plugin name, and the path value is the pathname (relative to dspace.dir/config) of the crosswalk stylesheet, e.g. "mycrosswalk.xslt"

For example, this configures a crosswalk named "LOM" using a stylesheet in config/crosswalks/d-lom.xsl under the DSpace "home" directory: 

  crosswalk.submission.stylesheet.LOM = crosswalks/d-lom.xsl

A dissemination crosswalk is described by a configuration key like 

  crosswalk.dissemination.PluginName.stylesheet = path
The alias names the Plugin name, and the path value is the pathname (relative to dspace.dir/config) of the crosswalk stylesheet, e.g. "mycrosswalk.xslt"

You can have two names point to the same crosswalk, just add two configuration entries with the same path, e.g. 

    crosswalk.submission.MyFormat.stylesheet = crosswalks/myformat.xslt
    crosswalk.submission.almost_DC.stylesheet = crosswalks/myformat.xslt

NOTE: This plugin will automatically reload any XSL stylesheet that was modified since it was last loaded. This lets you edit and test stylesheets without restarting DSpace.

You must use the PluginService to instantiate an XSLT crosswalk plugin, e.g. 

 IngestionCrosswalk xwalk = CoreServiceFactory.getInstance().getPluginService().getPlugin(IngestionCrosswalk
 .class, "LOM");

Since there is significant overhead in reading the properties file to configure the crosswalk, and a crosswalk instance may be used any number of times, we recommend caching one instance of the crosswalk for each alias and simply reusing those instances. The PluginService does this automatically.

Author:
Larry Stone

  • Field Details

    • DIM_NS

      public static final org.jdom2.Namespace DIM_NS
      DSpace XML Namespace in JDOM form.

    • CONFIG_PREFIX

      protected static final String CONFIG_PREFIX
      Prefix for all lines in the configuration file for XSLT plugins.
      See Also:

  • Constructor Details

    • XSLTCrosswalk

      public XSLTCrosswalk()

  • Method Details

    • makeAliases

      protected static String[] makeAliases(String direction)
      Derive list of plugin name from DSpace configuration entries for crosswalks.
      Parameters:
      direction - "dissemination" or "submission", so it looks for keys like crosswalk.submission.{NAME}.stylesheet
      Returns:
      names to be given to the plugins of that direction.

    • getTransformer

      protected Transformer getTransformer(String direction)
      Initialize the Transformation stylesheet from configured stylesheet file.
      Parameters:
      direction - the direction of xwalk, either "submission" or "dissemination"
      Returns:
      transformer or null if there was error initializing.