Enabled metadata extraction in WCM.

A set of extracters for different mimetypes can be activated across AVM land.
The XML extraction sample has been modified to be AVM-specific, and therefore
includes the necessary config to activate the metadata extraction in AVM.


git-svn-id: https://svn.alfresco.com/repos/alfresco-enterprise/alfresco/HEAD/root@6238 c4b6b30b-aa2e-2d43-bbcb-ca4b014f7261

config/alfresco/extension/wcm-xml-metadata-extracter-context.xml.sample

@@ -2,17 +2,66 @@
 <!DOCTYPE beans PUBLIC '-//SPRING//DTD BEAN//EN' 'http://www.springframework.org/dtd/spring-beans.dtd'>
  
 <!--
-   Sample configuration of a XmlMetadataExtracters.
+   Sample configuration of a XmlMetadataExtracter in use within the WCM environment.
    
    This show how XML metadata extraction can be set up to extract metadata from different
-   formats of XML.
+   formats of XML.  It also shows how metadata can be extracted in WCM projects.
    
    Since: 2.1
    Author: Derek Hulley
 -->
 <beans>
    
-   <!-- An extractor that operates on Alfresco Model XML -->
+   <!--
+      In order to limit the number of extractors active for Web Content Management, a separate registry
+      must be created for the extractors.
+   -->
+   <bean id="avmMetadataExtracterRegistry" class="org.alfresco.repo.content.metadata.MetadataExtracterRegistry" />
+   
+   <!--
+      Configure the AVM services to broadcast the content update notifications.
+   -->
+   <bean id="avmNodeService" class="org.alfresco.repo.avm.AVMNodeService" init-method="init">
+		<property name="dictionaryService">
+			<ref bean="dictionaryService"/>
+		</property>
+		<property name="avmService">
+			<ref bean="avmLockingAwareService"/>
+		</property>
+		<property name="policyComponent">
+			<ref bean="policyComponent"/>
+		</property>
+		<property name="invokePolicies">
+			<value>true</value>
+		</property>
+	</bean>
+   <bean id="avmMetadataExtracter" class="org.alfresco.repo.avm.AvmMetadataExtracter" init-method="init">
+      <property name="policyComponent">
+         <ref bean="policyComponent"/>
+      </property>
+      <property name="extracterAction">
+         <bean class="org.alfresco.repo.action.executer.ContentMetadataExtracter" >
+            <property name="dictionaryService">
+               <ref bean="dictionaryService"/>
+            </property>
+            <property name="nodeService">
+               <ref bean="avmNodeService" />
+            </property>
+            <property name="contentService">
+               <ref bean="contentService" />
+            </property>
+            <property name="metadataExtracterRegistry">
+               <ref bean="avmMetadataExtracterRegistry" />
+            </property>
+         </bean>
+      </property>
+   </bean>
+   
+   <!--
+      Configure an extractor that targets Alfresco Model XML files.
+      Although this inherits from the base extracter bean, the use of the 'init' method
+      means that it isn't automatically registered.
+   -->
    <bean id="extracter.xml.sample.AlfrescoModelMetadataExtracter"
          class="org.alfresco.repo.content.metadata.xml.XPathMetadataExtracter"
          parent="baseMetadataExtracter"
@@ -54,7 +103,7 @@
    
    <!--
       This selector examines the XML documents, executing the given XPath statements until a
-      result is found.
+      match is made.
    -->
    <bean
          id="extracter.xml.sample.selector.XPathSelector"
@@ -74,14 +123,19 @@
    
    <!--
       This is the face of the XML metadata extraction.  If passes the XML document to each of
-      the selectors, until one of them gives back a MetadataExtracter, which is then used as
+      the selectors, until one of them gives back a MetadataExtracter (via the selectors),
-      normal to extract the values.  The overwrite policy of the embedded extracters has no
+      which is then used as normal to extract the values.
-      effect.  It is only this extracter's policy that is used.
+      Note the use of the AVM-specific registry.
+      The overwrite policy of the embedded extracters has no effect.  It is only this extractor's
+      policy that is used.
    -->
    <bean
          id="extracter.xml.sample.XMLMetadataExtracter"
          class="org.alfresco.repo.content.metadata.xml.XmlMetadataExtracter"
          parent="baseMetadataExtracter">
+      <property name="registry">
+         <ref bean="avmMetadataExtracterRegistry" />
+      </property>
       <property name="overwritePolicy">
          <value>EAGER</value>
       </property>

source/java/org/alfresco/repo/avm/AvmMetadataExtracter.java

@@ -0,0 +1,98 @@
+/*
+ * Copyright (C) 2005-2007 Alfresco Software Limited.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+
+ * As a special exception to the terms and conditions of version 2.0 of 
+ * the GPL, you may redistribute this Program in connection with Free/Libre 
+ * and Open Source Software ("FLOSS") applications as described in Alfresco's 
+ * FLOSS exception.  You should have recieved a copy of the text describing 
+ * the FLOSS exception, and it is also available here: 
+ * http://www.alfresco.com/legal/licensing"
+ */
+package org.alfresco.repo.avm;
+
+import org.alfresco.repo.action.executer.ContentMetadataExtracter;
+import org.alfresco.repo.content.ContentServicePolicies;
+import org.alfresco.repo.policy.JavaBehaviour;
+import org.alfresco.repo.policy.PolicyComponent;
+import org.alfresco.service.cmr.repository.NodeRef;
+import org.alfresco.service.cmr.repository.StoreRef;
+import org.alfresco.service.namespace.NamespaceService;
+import org.alfresco.service.namespace.QName;
+
+/**
+ * A component that listens for changes to the content 
+ * 
+ * @since 2.1
+ * @author Derek Hulley
+ */
+public class AvmMetadataExtracter
+        implements ContentServicePolicies.OnContentUpdatePolicy
+{
+    /** the component to register the behaviour with */
+    private PolicyComponent policyComponent;
+    /** the action that will do the work */
+    private ContentMetadataExtracter extracterAction;
+    
+    /**
+     * @param policyComponent used for registrations
+     */
+    public void setPolicyComponent(PolicyComponent policyComponent)
+    {
+        this.policyComponent = policyComponent;
+    }
+
+    /**
+     * @param extracterAction       the action that will perform the actual extraction
+     */
+    public void setExtracterAction(ContentMetadataExtracter extracterAction)
+    {
+        this.extracterAction = extracterAction;
+    }
+
+    /**
+     * Registers the policy behaviour methods
+     */
+    public void init()
+    {
+        policyComponent.bindClassBehaviour(
+                QName.createQName(NamespaceService.ALFRESCO_URI, "onContentUpdate"),
+                this,
+                new JavaBehaviour(this, "onContentUpdate"));   
+    }
+
+    /**
+     * When the content changes, the metadata is extracted.
+     */
+    public void onContentUpdate(NodeRef nodeRef, boolean newContent)
+    {
+        /*
+         * The use of the action here is a supreme hack.  The code within the action is
+         * what we are after and it would be a shame to duplicate it.  Also, it is the
+         * intention that rules will eventually work against AVM, making this class
+         * obsolete.
+         */
+        
+        // Ignore everything non-AVM
+        if (!nodeRef.getStoreRef().getProtocol().equals(StoreRef.PROTOCOL_AVM))
+        {
+            return;
+        }
+        
+        // We extract the content whether it is new or not
+        extracterAction.executeImpl(null, nodeRef);
+    }
+}