roller/src/org/roller/persistence HierarchicalPersistentObject.java,NONE,1.1 PersistentObject.java,1.1,1.2

Update of /cvsroot/roller/roller/src/org/roller/persistence
In directory sc8-pr-cvs1:/tmp/cvs-serv21369/src/org/roller/persistence

Modified Files:
        PersistentObject.java 
Added Files:
        HierarchicalPersistentObject.java 
Log Message:
FolderData now extends HierarchicalPersistentObject

Almost done!

--- NEW FILE: HierarchicalPersistentObject.java ---
/*
 * Created on Jan 13, 2004
 */
package org.roller.persistence;

import org.roller.RollerException;
import org.roller.model.RollerFactory;
import org.roller.pojos.Assoc;

import java.util.Iterator;
import java.util.List;

/**
 * Abstract base class for hierarchical persistent objects. Provides generic
 * implementations of save and remove that know how to handle parents, 
children, 
 * and descendents.
 * 
 * @author David M Johnson
 */
public abstract class HierarchicalPersistentObject extends PersistentObject
{        
    protected HierarchicalPersistentObject mNewParent = null;
    
    /** Create an association between object and ancestor. */
    protected abstract Assoc createAssoc(
        HierarchicalPersistentObject object, 
        HierarchicalPersistentObject ancestor,
        String relation ) throws RollerException;
        
    /** Name of association class which must implement Assoc. */
    public abstract String getAssocClassName();
    
    /** Name of object propery in association class */
    public abstract String getObjectPropertyName();
    
    /** Name of ancestor propery in association class */
    public abstract String getAncestorPropertyName();
    
    /** Save this  object and ancestoral associations. */
    public void save() 
        throws RollerException
    {
        boolean fresh = (getId() == null || "".equals(getId()));
        PersistenceStrategy pstrategy =
            RollerFactory.getRoller().getPersistenceStrategy();
        pstrategy.store(this);
        if (fresh)
        {
            // Every fresh cat needs a parent assoc     
            Assoc parentAssoc = createAssoc(
                this, mNewParent, Assoc.PARENT);
            parentAssoc.save();
        }
        else if (null != mNewParent)
        {
            // New parent must be added to parentAssoc
            Assoc parentAssoc = getParentAssoc();
            parentAssoc.setAncestor(mNewParent);
            parentAssoc.save();
        }
        
        if (null != mNewParent)
        {
            // Clear out existing grandparent associations
            Iterator ancestors = getAncestorAssocs().iterator();
            while (ancestors.hasNext())
            {
                Assoc assoc = (Assoc)ancestors.next();
                if (assoc.getRelation().equals(Assoc.GRANDPARENT))
                {
                    assoc.remove();
                }
            }
            
            // Walk parent assocations, creating new grandparent associations
            int count = 0;
            Assoc currentAssoc = getParentAssoc();               
            while (null != currentAssoc.getAncestor())
            {
                if (count > 0) 
                {
                    Assoc assoc = createAssoc(this, 
                        currentAssoc.getAncestor(), 
                        Assoc.GRANDPARENT);
                    assoc.save();
                }                
                currentAssoc = currentAssoc.getAncestor().getParentAssoc();
                count++;
            }
        }
        
        // Clear new parent now that new parent has been saved
        mNewParent = null;
    }

    /** Remove self, all decendent children and associations. */
    public void remove() 
        throws RollerException
    {
        PersistenceStrategy pstrategy =
            RollerFactory.getRoller().getPersistenceStrategy();

        // loop to remove all of my descendent categories and associations
        Iterator catIter = this.getAllDescendentAssocs().iterator();
        while (catIter.hasNext())
        {
            Assoc assoc = (Assoc)catIter.next();
            HierarchicalPersistentObject cat = assoc.getObject();
            
            // remove my descendent's parent and grandparent associations
            Iterator ancestors = cat.getAncestorAssocs().iterator();
            while (ancestors.hasNext())
            {
                Assoc dassoc = (Assoc)ancestors.next();
                dassoc.remove();
            }
            
            // remove decendent association and descendent category
            assoc.remove();
            //pstrategy.remove(cat);
        }

        // loop to remove my own parent and grandparent associations
        Iterator ancestors = getAncestorAssocs().iterator();
        while (ancestors.hasNext())
        {
            Assoc assoc = (Assoc)ancestors.next();
            assoc.remove();
        }
        
        // remove myself
        pstrategy.remove(this);        
    }

    /** Query database to get parent association. */
    protected Assoc getParentAssoc() 
        throws RollerException
    {
        String className = getAssocClassName();
        String objectColName = getObjectPropertyName();

        QueryFactory factory =
          RollerFactory.getRoller().getPersistenceStrategy().getQueryFactory();
        Query query = factory.createQuery(className);
        
        Condition catCond = 
            factory.createCondition(objectColName, Query.EQ, this);
        Condition parentCond =
            factory.createCondition("relation",Query.EQ,Assoc.PARENT);
        query.setWhere(factory.createCondition(catCond, Query.AND, parentCond));
        List parents = query.execute();
        
        if (parents.size() > 1)
        {
            throw new RollerException("ERROR: more than one parent");
        }
        else if (parents.size() == 1)
        {
            return (Assoc) parents.get(0);
        }
        else
        {
            return null;
        }
    }

    /** Get child associations, those whose parent is this category. */
    protected List getChildAssocs() 
        throws RollerException
    {
        String className = getAssocClassName();
        String assocColName = getAncestorPropertyName();       

        QueryFactory factory =
            RollerFactory
                .getRoller()
                .getPersistenceStrategy()
                .getQueryFactory();
        Query query = factory.createQuery(className);
        Condition catCond = factory.createCondition(assocColName, Query.EQ, 
this);
        Condition parentCond =
            factory.createCondition(
                "relation",
                Query.EQ,
                Assoc.PARENT);
        query.setWhere(factory.createCondition(catCond, Query.AND, parentCond));
        return query.execute();
    }

    /** 
     * Get all descendent associations, those that have this category as an 
     * ancestor, public for testing purposes only.
     */
    public List getAllDescendentAssocs() 
        throws RollerException
    {
        String className = getAssocClassName();
        String assocColName = getAncestorPropertyName();       
        QueryFactory factory =
           RollerFactory.getRoller().getPersistenceStrategy().getQueryFactory();
        Query query = factory.createQuery(className);
        query.setWhere(factory.createCondition(assocColName, Query.EQ, this));
        return query.execute();
    }
    
    /** 
     * Get all ancestor associations, public for testing purposes only. 
     */
    public List getAncestorAssocs() 
        throws RollerException
    {
        String className = getAssocClassName();
        String objectColName = getObjectPropertyName();
        QueryFactory factory =
           RollerFactory.getRoller().getPersistenceStrategy().getQueryFactory();
        Query query = factory.createQuery(className);
        query.setWhere(factory.createCondition(objectColName, Query.EQ, this));
        return query.execute();
    }  
}

Index: PersistentObject.java
===================================================================
RCS file: 
/cvsroot/roller/roller/src/org/roller/persistence/PersistentObject.java,v
retrieving revision 1.1
retrieving revision 1.2
diff -C2 -d -r1.1 -r1.2
*** PersistentObject.java       1 Dec 2003 01:18:50 -0000       1.1
--- PersistentObject.java       17 Jan 2004 22:46:57 -0000      1.2
***************
*** 3,6 ****
--- 3,8 ----
  
  import org.exolab.castor.jdo.TimeStampable;
+ import org.roller.RollerException;
+ import org.roller.model.RollerFactory;
  
  import java.io.Serializable;
***************
*** 39,42 ****
--- 41,58 ----
                mTimeStamp = timeStamp;
        }
+     
+     public void save() throws RollerException 
+     {
+         PersistenceStrategy pstrategy =
+             RollerFactory.getRoller().getPersistenceStrategy();
+         pstrategy.store(this);
+     }
+     
+     public void remove() throws RollerException 
+     {
+         PersistenceStrategy pstrategy =
+             RollerFactory.getRoller().getPersistenceStrategy();
+         pstrategy.remove(this);
+     }
  }
  




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