XHTMLHeadDisseminationCrosswalk (DSpace Kernel :: API and Implementation 4.4 API)

java.lang.Object
- org.dspace.core.SelfNamedPlugin
- - org.dspace.content.crosswalk.XHTMLHeadDisseminationCrosswalk

All Implemented Interfaces:

DisseminationCrosswalk
```
public class XHTMLHeadDisseminationCrosswalk
extends SelfNamedPlugin
implements DisseminationCrosswalk
```
Crosswalk for creating appropriate <meta> elements to appear in the item display page for a particular item, for improving automated processing of the page (e.g. by search engines). The metadata included should be as rich yet standards-compliant as possible.
The configuration file ${dspace.dir}/config/xhtml-head-item.properties contains the relevant mappings. Note: where there is a custom qualifier for which no corresponding mapping exists, the crosswalk will remove the qualifier and try again with just the element.
e.g. if a field exists in the database "dc.contributor.editor", and there is no dc.contributor.editor property below, the mapping for "dc.contributor" will be used. If an element in the item metadata record does not appear in the configuration, it is simply ignored; the emphasis here is on exposing standards-compliant metadata.
TODO: This may usefully be extended later to work with communities and collections.

Version:

$Revision$

Author:

Robert Tansley

Field Summary
- Fields inherited from interface org.dspace.content.crosswalk.DisseminationCrosswalk
  XSI_NS

Constructor Summary

Constructors
Constructor and Description

XHTMLHeadDisseminationCrosswalk()

Constructors
Constructor and Description
`XHTMLHeadDisseminationCrosswalk()`

Method Summary

Methods
Modifier and Type	Method and Description
`boolean`	`canDisseminate(DSpaceObject dso)` Predicate: Can this disseminator crosswalk the given object.
`org.jdom.Element`	`disseminateElement(DSpaceObject dso)` This generates a <head> element around the metadata; in general this will probably not be used
`List<org.jdom.Element>`	`disseminateList(DSpaceObject dso)` Return <meta> elements that can be put in the <head> element of an XHTML document.
`org.jdom.Namespace[]`	`getNamespaces()` Get XML namespaces of the elements this crosswalk may return.
`static String[]`	`getPluginNames()`
`String`	`getSchemaLocation()` Get the XML Schema location(s) of the target metadata format.
`boolean`	`preferList()` Predicate: Does this disseminator prefer to return a list of Elements, rather than a single root Element?

Methods inherited from class org.dspace.core.SelfNamedPlugin
getPluginInstanceName, setPluginInstanceName

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - XHTMLHeadDisseminationCrosswalk
```
public XHTMLHeadDisseminationCrosswalk()
                                throws IOException
```
    Throws:
    
    IOException
- Method Detail
  - canDisseminate
```
public boolean canDisseminate(DSpaceObject dso)
```
    Description copied from interface: DisseminationCrosswalk
    
    Predicate: Can this disseminator crosswalk the given object. Needed by OAI-PMH server implementation.
    
    Specified by:
    
    canDisseminate in interface DisseminationCrosswalk
    
    Parameters:
    dso - dspace object, e.g. an Item.
    
    Returns:
    true when disseminator is capable of producing metadata.
  - disseminateElement
```
public org.jdom.Element disseminateElement(DSpaceObject dso)
                                    throws CrosswalkException,
                                           IOException,
                                           SQLException,
                                           AuthorizeException
```
    This generates a <head> element around the metadata; in general this will probably not be used
    
    Specified by:
    
    disseminateElement in interface DisseminationCrosswalk
    
    Parameters:
    dso - the DSpace Object whose metadata to export.
    
    Returns:
    root Element of the target metadata, never null
    
    Throws:
    
    CrosswalkInternalException - (CrosswalkException) failure of the crosswalk itself.
    
    CrosswalkObjectNotSupported - (CrosswalkException) Cannot crosswalk this kind of DSpace object.
    
    IOException - I/O failure in services this calls
    
    SQLException - Database failure in services this calls
    
    AuthorizeException - current user not authorized for this operation.
    
    CrosswalkException
  - disseminateList
```
public List<org.jdom.Element> disseminateList(DSpaceObject dso)
                                       throws CrosswalkException,
                                              IOException,
                                              SQLException,
                                              AuthorizeException
```
    Return <meta> elements that can be put in the <head> element of an XHTML document.
    
    Specified by:
    
    disseminateList in interface DisseminationCrosswalk
    
    Parameters:
    dso - the DSpace Object whose metadata to export.
    
    Returns:
    results of crosswalk as list of XML elements.
    
    Throws:
    
    CrosswalkInternalException - (CrosswalkException) failure of the crosswalk itself.
    
    CrosswalkObjectNotSupported - (CrosswalkException) Cannot crosswalk this kind of DSpace object.
    
    IOException - I/O failure in services this calls
    
    SQLException - Database failure in services this calls
    
    AuthorizeException - current user not authorized for this operation.
    
    CrosswalkException
  - getNamespaces
```
public org.jdom.Namespace[] getNamespaces()
```
    Description copied from interface: DisseminationCrosswalk
    
    Get XML namespaces of the elements this crosswalk may return. Returns the XML namespaces (as JDOM objects) of the root element.
    
    Specified by:
    
    getNamespaces in interface DisseminationCrosswalk
    
    Returns:
    array of namespaces, which may be empty.
  - getSchemaLocation
```
public String getSchemaLocation()
```
    Description copied from interface: DisseminationCrosswalk
    
    Get the XML Schema location(s) of the target metadata format. Returns the string value of the xsi:schemaLocation attribute that should be applied to the generated XML.
    It may return the empty string if no schema is known, but crosswalk authors are strongly encouraged to implement this call so their output XML can be validated correctly.
    
    Specified by:
    
    getSchemaLocation in interface DisseminationCrosswalk
    
    Returns:
    SchemaLocation string, including URI namespace, followed by whitespace and URI of XML schema document, or empty string if unknown.
  - preferList
```
public boolean preferList()
```
    Description copied from interface: DisseminationCrosswalk
    
    Predicate: Does this disseminator prefer to return a list of Elements, rather than a single root Element?
    Some metadata formats have an XML schema without a root element, for example, the Dublin Core and Qualified Dublin Core formats. This would be true for a crosswalk into QDC, since it would "prefer" to return a list, since any root element it has to produce would have to be part of a nonstandard schema. In most cases your implementation will want to return false
    
    Specified by:
    
    preferList in interface DisseminationCrosswalk
    
    Returns:
    true when disseminator prefers you call disseminateList().
  - getPluginNames
```
public static String[] getPluginNames()
```

Class XHTMLHeadDisseminationCrosswalk

Field Summary

Fields inherited from interface org.dspace.content.crosswalk.DisseminationCrosswalk

Constructor Summary

Method Summary

Methods inherited from class org.dspace.core.SelfNamedPlugin

Methods inherited from class java.lang.Object

Constructor Detail

XHTMLHeadDisseminationCrosswalk

Method Detail

canDisseminate

disseminateElement

disseminateList

getNamespaces

getSchemaLocation

preferList

getPluginNames