NEW: Add support for push operator on ArrayList (Fixes #1539)

model/ArrayList.php

@@ -281,9 +281,14 @@ class ArrayList extends ViewableData implements SS_List, SS_Filterable, SS_Sorta
 	 */
 	public function map($keyfield = 'ID', $titlefield = 'Title') {
 		$map = array();
+
 		foreach ($this->items as $item) {
-			$map[$this->extractValue($item, $keyfield)] = $this->extractValue($item, $titlefield);
+			$map[$this->extractValue($item, $keyfield)] = $this->extractValue(
+				$item, 
+				$titlefield
+			);
 		}
+
 		return $map;
 	}
 
@@ -296,7 +301,9 @@ class ArrayList extends ViewableData implements SS_List, SS_Filterable, SS_Sorta
 	 */
 	public function find($key, $value) {
 		foreach ($this->items as $item) {
-			if ($this->extractValue($item, $key) == $value) return $item;
+			if ($this->extractValue($item, $key) == $value) {
+				return $item;
+			}
 		}
 	}
 
@@ -308,9 +315,11 @@ class ArrayList extends ViewableData implements SS_List, SS_Filterable, SS_Sorta
 	 */
 	public function column($colName = 'ID') {
 		$result = array();
+
 		foreach ($this->items as $item) {
 			$result[] = $this->extractValue($item, $colName);
 		}
+
 		return $result;
 	}
 
@@ -410,9 +419,11 @@ class ArrayList extends ViewableData implements SS_List, SS_Filterable, SS_Sorta
 	 */
 	public function canFilterBy($by) {
 		$firstRecord = $this->first();
+
 		if ($firstRecord === false) {
 			return false;
 		}
+
 		return array_key_exists($by, $firstRecord);
 	}
 
@@ -470,9 +481,11 @@ class ArrayList extends ViewableData implements SS_List, SS_Filterable, SS_Sorta
 	
 	public function byID($id) {
 		$firstElement = $this->filter("ID", $id)->first();
+
 		if ($firstElement === false) {
 			return null;
 		}
+
 		return $firstElement;
 	}
 
@@ -490,10 +503,13 @@ class ArrayList extends ViewableData implements SS_List, SS_Filterable, SS_Sorta
 				gettype($callback)
 			));
 		}
+
 		$output = ArrayList::create();
+
 		foreach($this as $item) {
 			if(call_user_func($callback, $item, $this)) $output->push($item);
 		}
+
 		return $output;
 	}
 
@@ -588,8 +604,12 @@ class ArrayList extends ViewableData implements SS_List, SS_Filterable, SS_Sorta
 	 * @param mixed $value
 	 */
 	public function offsetSet($offset, $value) {
+		if($offset == null) {
+			$this->items[] = $value;
+		} else {
 			$this->items[$offset] = $value;
 		}
+	}
 
 	/**
 	 * Unset an item with the key in $key

tests/model/ArrayListTest.php

@@ -5,6 +5,20 @@
  */
 class ArrayListTest extends SapphireTest {
 
+	public function testPushOperator() {
+		$list = new ArrayList(array(
+			array('Num' => 1)
+		));
+
+		$list[] = array('Num' => 2);
+		$this->assertEquals(2, count($list));
+		$this->assertEquals(array('Num' => 2), $list->last());
+
+		$list[] = array('Num' => 3);
+		$this->assertEquals(3, count($list));
+		$this->assertEquals(array('Num' => 3), $list->last());
+	}
+
 	public function testArrayAccessExists() {
 		$list = new ArrayList(array(
 			$one = new DataObject(array('Title' => 'one')),