From cea4bf11d18bbe9c82d2fbd02e8faeb100dc1db6 Mon Sep 17 00:00:00 2001
From: Ben Alex <ben.alex@springsource.com>
Date: Wed, 20 Apr 2005 12:06:23 +0000
Subject: [PATCH] Add scrollWithSubclasses() method.

---
 .../org/acegisecurity/domain/dao/Dao.java     | 27 +++++++++++++++++--
 .../domain/hibernate/DaoHibernate.java        | 20 +++++++++++---
 2 files changed, 41 insertions(+), 6 deletions(-)

diff --git a/domain/src/main/java/org/acegisecurity/domain/dao/Dao.java b/domain/src/main/java/org/acegisecurity/domain/dao/Dao.java
index 920d823eea..0eb490b3e7 100644
--- a/domain/src/main/java/org/acegisecurity/domain/dao/Dao.java
+++ b/domain/src/main/java/org/acegisecurity/domain/dao/Dao.java
@@ -94,7 +94,7 @@ public interface Dao {
     public void delete(PersistableEntity value);
 
     /**
-     * Return all persistent instances.
+     * Return all persistent instances, including subclasses.
      *
      * @return all persistence instances (an empty <code>List</code> will be
      *         returned if no matches are found)
@@ -133,7 +133,8 @@ public interface Dao {
      * the query by example evaluation.
      * </p>
      *
-     * @param value parameters to filter on
+     * @param value parameters to filter on (the class of this object will be
+     *        added to the filter)
      * @param firstElement the first result (start at zero to obtain all
      *        results)
      * @param maxElements the maximum number of results desired for this page
@@ -148,6 +149,28 @@ public interface Dao {
     public PaginatedList scroll(PersistableEntity value, int firstElement,
         int maxElements, String orderByAsc);
 
+    /**
+     * Find persistent instances with properties matching those of the passed
+     * <code>PersistableEntity</code>, ignoring the class of the passed
+     * <code>PersistableEntity</code> (useful if you pass a superclass, as you
+     * want to find all subclass instances which match).
+     *
+     * @param value parameters to filter on (the class of this object will NOT
+     *        be added to the filter)
+     * @param firstElement the first result (start at zero to obtain all
+     *        results)
+     * @param maxElements the maximum number of results desired for this page
+     *        of the result set
+     * @param orderByAsc the property name of the
+     *        <code>PersistableEntity</code> that should be used to order the
+     *        results
+     *
+     * @return the requested page of the result list (a properly formed
+     *         <code>PaginatedList</code> is returned if no results match)
+     */
+    public PaginatedList scrollWithSubclasses(PersistableEntity value,
+        int firstElement, int maxElements, String orderByAsc);
+
     /**
      * Indicates whether the DAO instance provides persistence services for the
      * specified class.
diff --git a/domain/src/main/java/org/acegisecurity/domain/hibernate/DaoHibernate.java b/domain/src/main/java/org/acegisecurity/domain/hibernate/DaoHibernate.java
index 80d59cbd83..d3429ad3b3 100644
--- a/domain/src/main/java/org/acegisecurity/domain/hibernate/DaoHibernate.java
+++ b/domain/src/main/java/org/acegisecurity/domain/hibernate/DaoHibernate.java
@@ -109,12 +109,24 @@ public class DaoHibernate extends HibernateDaoSupport implements Dao,
         Assert.notNull(value);
         Assert.hasText(orderByAsc,
             "An orderByAsc is required (why not use your identity property?)");
+		Assert.isInstanceOf(this.supportsClass, value, "Can only scroll with values this DAO supports");
 
         return (PaginatedList) getHibernateTemplate().execute(getFindByValueCallback(
-                value, firstElement, maxElements, Order.asc(orderByAsc)));
+				value.getClass(), value, firstElement, maxElements, Order.asc(orderByAsc)));
     }
 
-    public boolean supports(Class clazz) {
+    public PaginatedList scrollWithSubclasses(PersistableEntity value, int firstElement,
+	        int maxElements, String orderByAsc) {
+	        Assert.notNull(value);
+	        Assert.hasText(orderByAsc,
+	            "An orderByAsc is required (why not use your identity property?)");
+			Assert.isInstanceOf(this.supportsClass, value, "Can only scroll with values this DAO supports");
+
+	        return (PaginatedList) getHibernateTemplate().execute(getFindByValueCallback(
+					this.supportsClass, value, firstElement, maxElements, Order.asc(orderByAsc)));
+	    }
+
+	public boolean supports(Class clazz) {
         Assert.notNull(clazz);
 
         return this.supportsClass.equals(clazz);
@@ -187,12 +199,12 @@ public class DaoHibernate extends HibernateDaoSupport implements Dao,
      *
      * @return a PaginatedList containing the requested objects
      */
-    private HibernateCallback getFindByValueCallback(final Object bean,
+    private HibernateCallback getFindByValueCallback(final Class whichClass, final Object bean,
         final int firstElement, final int count, final Order order) {
         return new HibernateCallback() {
                 public Object doInHibernate(Session session)
                     throws HibernateException {
-                    Criteria criteria = session.createCriteria(bean.getClass());
+                    Criteria criteria = session.createCriteria(whichClass);
 
                     criteria.addOrder(order);