API CHANGE: Add removeByID(), canSortBy(), and byID() to DataList and its subclasses.

core/model/DataList.php

@@ -77,6 +77,13 @@ class DataList extends DataObjectSet {
 		return $this;
 	}
 	
+	/**
+	 * Returns true if this DataList can be sorted by the given field.
+	 */
+	public function canSortBy($field) {
+	    return $this->dataQuery()->query()->canSortBy($field);
+	}
+
 	/**
 	 * Add an join clause to this data list's query.
 	 */
@@ -243,6 +250,14 @@ class DataList extends DataObjectSet {
 		return $this;
 	}
 
+	/**
+	 * Return the item of the given ID
+	 */
+	public function byID($id) {
+		$baseClass = ClassInfo::baseDataClass($this->dataClass);
+		return $this->filter("\"$baseClass\".\"ID\" = " . (int)$id)->First();
+	}
+	
 	/**
 	 * Return a single column from this DataList.
 	 * @param $colNum The DataObject field to return.
@@ -318,7 +333,7 @@ class DataList extends DataObjectSet {
 	 */
 	function removeMany($idList) {
 		foreach($idList as $id) {
-			$this->remove($id);
+			$this->removeByID($id);
 		}
 	}
 
@@ -357,6 +372,14 @@ class DataList extends DataObjectSet {
 
 	}
 
+    /**
+     * Remove an item from this DataList by ID
+     */
+	function removeByID($itemID) {
+	    $item = $this->byID($itemID);
+	    if($item) return $item->delete();
+	}
+
 	// Methods that won't function on DataLists
 	
 	function push($item) {

core/model/HasManyList.php

@@ -60,12 +60,21 @@ class HasManyList extends RelationList {
 	/**
 	 * Remove an item from this relation.
 	 * Doesn't actually remove the item, it just clears the foreign key value.
-	 * @param $item The DataObject to be removed, or its ID 
+	 * @param $itemID The ID of the item to be removed
+	 */
+	function removeByID($itemID) {
+        $item = $this->byID($item);
+        return $this->remove($item);
+    }
+    
+	/**
+	 * Remove an item from this relation.
+	 * Doesn't actually remove the item, it just clears the foreign key value.
+	 * @param $item The DataObject to be removed
 	 * @todo Maybe we should delete the object instead? 
 	 */
 	function remove($item) {
-		if(is_numeric($item)) $item = DataObject::get_by_id($this->dataClass, $item);
+        if(!($item instanceof $this->dataClass)) throw new InvalidArgumentException("HasManyList::remove() expecting a $this->dataClass object, or ID value", E_USER_ERROR);
-		else if(!($item instanceof $this->dataClass)) user_eror("HasManyList::remove() expecting a $this->dataClass object, or ID value", E_USER_ERROR);
 
 		$fk = $this->foreignKey;
 		$item->$fk = null;

core/model/ManyManyList.php

@@ -78,7 +78,7 @@ class ManyManyList extends RelationList {
 		}
 
 		// Delete old entries, to prevent duplication
-		$this->remove($itemID);
+		$this->removeById($itemID);
 
 		// Insert new entry
 		$manipulation = array();
@@ -97,12 +97,21 @@ class ManyManyList extends RelationList {
 	/**
 	 * Remove the given item from this list.
 	 * Note that for a ManyManyList, the item is never actually deleted, only the join table is affected
-	 * @param $item The data object or its ID
+	 * @param $itemID The ID of the item to remove.
 	 */
 	function remove($item) {
-		if(is_numeric($item)) $itemID = $item;
+        if(!($item instanceof $this->dataClass)) throw new InvalidArgumentException("ManyManyList::remove() expecting a $this->dataClass object");
-		else if($item instanceof $this->dataClass) $itemID = $item->ID;
+        
-		else user_eror("ManyManyList::remove() expecting a $this->dataClass object, or ID value", E_USER_ERROR);
+        return $this->removeByID($item->ID);
+	}
+
+	/**
+	 * Remove the given item from this list.
+	 * Note that for a ManyManyList, the item is never actually deleted, only the join table is affected
+	 * @param $itemID The item it
+	 */
+	function removeByID($itemID) {
+	    if(!is_numeric($itemID)) throw new InvalidArgumentException("ManyManyList::removeById() expecting an ID");
 
 		$query = new SQLQuery("*", array($this->joinTable));
 		$query->delete = true;

tests/model/DataExtensionTest.php

@@ -66,7 +66,7 @@ class DataExtensionTest extends SapphireTest {
 		$parent->Faves()->add($obj2->ID);
 		$this->assertEquals(2, $parent->Faves()->Count());
 		
-		$parent->Faves()->remove($obj2->ID);
+		$parent->Faves()->removeByID($obj2->ID);
 		$this->assertEquals(1, $parent->Faves()->Count());
 	}
 	

tests/model/DataObjectTest.php

@@ -310,7 +310,7 @@ class DataObjectTest extends SapphireTest {
 	   );
 	   
 	   // test removing single DataObject by ID
-	   $player1->Teams()->remove($team1->ID);
+	   $player1->Teams()->removeByID($team1->ID);
 	   $player1->flushCache();
 	   $compareTeams = new ComponentSet();
 	   $this->assertEquals(
@@ -1067,6 +1067,38 @@ class DataObjectTest extends SapphireTest {
 		$objEmpty->Title = '0'; // 
 		$this->assertFalse($objEmpty->isEmpty(), 'Zero value in attribute considered non-empty');
 	}
+	
+	/**
+	 * Test DataList->byID()
+	 */
+	function testByID() {
+	    $id = $this->idFromFixture('DataObjectTest_Team','team2');
+	    $this->assertEquals('Team 2', DataObject::get("DataObjectTest_Team")->byID($id)->Title);
+	}
+
+	/**
+	 * Test DataList->removeByID()
+	 */
+	function testRemoveByID() {
+	    $id = $this->idFromFixture('DataObjectTest_Team','team2');
+	    DataObject::get("DataObjectTest_Team")->removeByID($id);
+	    
+	    $this->assertNull(DataObject::get("DataObjectTest_Team")->byID($id));
+	}
+
+	/**
+	 * Test DataList->canSortBy()
+	 */
+	function testCanSortBy() {
+	    // Basic check
+	    $this->assertTrue(DataObject::get("DataObjectTest_Team")->canSortBy("Title"));
+	    $this->assertFalse(DataObject::get("DataObjectTest_Team")->canSortBy("SomethingElse"));
+
+        // Subclasses
+	    $this->assertTrue(DataObject::get("DataObjectTest_SubTeam")->canSortBy("Title"));
+	    $this->assertTrue(DataObject::get("DataObjectTest_SubTeam")->canSortBy("SubclassDatabaseField"));
+	}
+
 }
 
 class DataObjectTest_Player extends Member implements TestOnly {