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Date: 28 Mar 2004 06:12:29 -0000
Message-ID: <20040328061229.12178.qmail@minotaur.apache.org>
From: skitching@apache.org
To: jakarta-commons-cvs@apache.org
Subject: cvs commit:
 jakarta-commons/digester/src/java/org/apache/commons/digester/plugins
 PluginManager.java

skitching    2004/03/27 22:12:29

  Modified:    digester/src/java/org/apache/commons/digester/plugins Tag:
                        DIGESTER_PLUGIN_REFACTORING_BRANCH
                        PluginManager.java
  Log:
  * Now holds a reference to a PerDigesterResources object
  * added findLoader method which scans the list of RuleFinders in the
    PerDigesterResources object to find a suitable RuleLoader for a
    plugin declaration.
  
  Revision  Changes    Path
  No                   revision
  No                   revision
  1.9.2.1   +60 -5     jakarta-commons/digester/src/java/org/apache/commons/digester/plugins/PluginManager.java
  
  Index: PluginManager.java
  ===================================================================
  RCS file: /home/cvs/jakarta-commons/digester/src/java/org/apache/commons/digester/plugins/PluginManager.java,v
  retrieving revision 1.9
  retrieving revision 1.9.2.1
  diff -u -r1.9 -r1.9.2.1
  --- PluginManager.java	29 Feb 2004 02:22:15 -0000	1.9
  +++ PluginManager.java	28 Mar 2004 06:12:29 -0000	1.9.2.1
  @@ -17,6 +17,9 @@
   package org.apache.commons.digester.plugins;
   
   import java.util.HashMap;
  +import java.util.List;
  +import java.util.Properties;
  +import java.util.Iterator;
   
   import org.apache.commons.digester.Digester;
   
  @@ -26,8 +29,7 @@
    * Coordinates between PluginDeclarationRule and PluginCreateRule objects,
    * providing a place to share data between instances of these rules.
    * <p>
  - * One instance of this class exists per PluginRules instance,
  - * ie one per Digester instance.
  + * One instance of this class exists per PluginRules instance.
    */
   
   public class PluginManager {
  @@ -40,16 +42,25 @@
   
       /** the parent manager to which this one may delegate lookups. */
       private PluginManager parent;
  -
  +    
  +    /** 
  +     * The object containing data that should only exist once for each
  +     * Digester instance.
  +     */
  +    private PerDigesterResources perDigesterResources;
  +    
       //------------------- constructors ---------------------------------------
       
       /** Constructor. */
  -    public PluginManager() {
  +    public PluginManager(PerDigesterResources r) {
  +        perDigesterResources = r;
       }
   
       /** Constructor. */
  -    public PluginManager(PluginManager parent) {
  +    public PluginManager(PerDigesterResources r, PluginManager parent) {
           this.parent = parent;
  +        this.perDigesterResources = r;
  +        // assert r == parent.perDigesterResources
       }
       
       //------------------- methods --------------------------------------------
  @@ -112,5 +123,49 @@
           }
   
           return decl;
  +    }
  +
  +    /**
  +     * Given a plugin class and some associated properties, scan the
  +     * list of known RuleFinder instances until one detects a source of
  +     * custom rules for this plugin (aka a RuleLoader).
  +     * <p>
  +     * If no source of custom rules can be found, null is returned.
  +     */
  +    public RuleLoader findLoader(Digester digester, String id, 
  +                        Class pluginClass, Properties props) 
  +                        throws PluginException {    
  +
  +        // iterate over the list of RuleFinders, trying each one 
  +        // until one of them locates a source of dynamic rules given
  +        // this specific plugin class and the associated declaration 
  +        // properties.
  +        Log log = LogUtils.getLogger(digester);
  +        boolean debug = log.isDebugEnabled();
  +        log.debug("scanning ruleFinders to locate loader..");
  +        
  +        List ruleFinders = perDigesterResources.getRuleFinders();
  +        RuleLoader ruleLoader = null;
  +        try {
  +            for(Iterator i = ruleFinders.iterator(); 
  +                i.hasNext() && ruleLoader == null; ) {
  +                    
  +                RuleFinder finder = (RuleFinder) i.next();
  +                if (debug) {
  +                    log.debug("checking finder of type " + finder.getClass().getName());
  +                }
  +                ruleLoader = finder.findLoader(digester, pluginClass, props);
  +            }
  +        }
  +        catch(PluginException e) {
  +            throw new PluginException(
  +                "Unable to locate plugin rules for plugin"
  +                + " with id [" + id + "]"
  +                + ", and class [" + pluginClass.getName() + "]"
  +                + ":" + e.getMessage(), e.getCause());
  +        }
  +        log.debug("scanned ruleFinders.");
  +        
  +        return ruleLoader;
       }
   }
  
  
  

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