Examples of com.itextpdf.xmp.XMPSchemaRegistry

com.itextpdf.xmp.XMPSchemaRegistry

The schema registry keeps track of all namespaces and aliases used in the XMP metadata. At initialisation time, the default namespaces and default aliases are automatically registered. Namespaces must be registered before used in namespace URI parameters or path expressions. Within the XMP Toolkit the registered namespace URIs and prefixes must be unique. Additional namespaces encountered when parsing RDF are automatically registered. The namespace URI should always end in an XML name separator such as '/' or '#'. This is because some forms of RDF shorthand catenate a namespace URI with an element name to form a new URI.

Aliases in XMP serve the same purpose as Windows file shortcuts, Macintosh file aliases, or UNIX file symbolic links. The aliases are simply multiple names for the same property. One distinction of XMP aliases is that they are ordered, there is an alias name pointing to an actual name. The primary significance of the actual name is that it is the preferred name for output, generally the most widely recognized name.

The names that can be aliased in XMP are restricted. The alias must be a top level property name, not a field within a structure or an element within an array. The actual may be a top level property name, the first element within a top level array, or the default element in an alt-text array. This does not mean the alias can only be a simple property. It is OK to alias a top level structure or array to an identical top level structure or array, or to the first item of an array of structures. @since 27.01.2006

   * @throws XMPException thown on parsing errors
   */
  private static XMPNode addChildNode(XMPMetaImpl xmp, XMPNode xmpParent, Node xmlNode,
      String value, boolean isTopLevel) throws XMPException
  {
    XMPSchemaRegistry registry = XMPMetaFactory.getSchemaRegistry();
    String namespace = xmlNode.getNamespaceURI();
    String childName;
    if (namespace != null)
    {
      if (NS_DC_DEPRECATED.equals(namespace))
      {
        // Fix a legacy DC namespace
        namespace = NS_DC;
      }
      
      String prefix = registry.getNamespacePrefix(namespace);
      if (prefix == null)
      {
        prefix = xmlNode.getPrefix() != null ? xmlNode.getPrefix() : DEFAULT_PREFIX;
        prefix = registry.registerNamespace(namespace, prefix);
      }
      childName = prefix + xmlNode.getLocalName();
    }
    else
    {
      throw new XMPException(
        "XML namespace required for all elements and attributes", BADRDF);
    }


    
    // create schema node if not already there
    PropertyOptions childOptions = new PropertyOptions();
    boolean isAlias = false;
    if (isTopLevel)
    {
      // Lookup the schema node, adjust the XMP parent pointer.
      // Incoming parent must be the tree root.
      XMPNode schemaNode = XMPNodeUtils.findSchemaNode(xmp.getRoot(), namespace,
        DEFAULT_PREFIX, true);
      schemaNode.setImplicit(false);  // Clear the implicit node bit.
      // need runtime check for proper 32 bit code.
      xmpParent = schemaNode;
      
      // If this is an alias set the alias flag in the node 
      // and the hasAliases flag in the tree.
      if (registry.findAlias(childName) != null)
      {
        isAlias = true;
        xmp.getRoot().setHasAliases(true);
        schemaNode.setHasAliases(true);
      }

Examples of com.itextpdf.xmp.XMPSchemaRegistry

Related Classes of com.itextpdf.xmp.XMPSchemaRegistry