update refactoring of children() method

- is now find('children')
- test cases updated

src/Model/Behavior/TreeBehavior.php

@@ -40,7 +40,10 @@ class TreeBehavior extends Behavior {
  * @var array
  */
 	protected static $_defaultConfig = [
-		'implementedFinders' => ['path' => 'findPath'],
+		'implementedFinders' => [
+			'path' => 'findPath',
+			'children' => 'findChildren',
+		],
 		'parent' => 'parent_id',
 		'left' => 'lft',
 		'right' => 'rght',
@@ -100,57 +103,50 @@ class TreeBehavior extends Behavior {
 /**
  * Get the child nodes of the current model
  *
- * If the direct parameter is set to true, only the direct children are returned (based upon the parent_id field)
+ * Available options are:
+ *
+ * - direct: Whether to return only the direct, or all, children
+ * - order: SQL ORDER BY conditions (e.g. ['price' => 'DESC']) defaults to the tree order
+ *
+ * If the direct option is set to true, only the direct children are returned (based upon the parent_id field)
  * If false is passed for the id parameter, top level, or all (depending on direct parameter appropriate) are counted.
  *
  * @param integer|string $id The ID of the record to read
- * @param boolean $direct whether to return only the direct, or all, children
- * @param string|array $fields Either a single string of a field name, or an array of field names
- * @param array $order SQL ORDER BY conditions (e.g. ['price' => 'DESC']) defaults to the tree order
- * @param integer $limit SQL LIMIT clause, for calculating items per page.
- * @param integer $page Page number, for accessing paged data
- * @return array Array of child nodes
+ * @param array $options Array of options as described above
+ * @return \Cake\ORM\Query
  */
-	public function children($id, $direct = false, $fields = [], $order = [], $limit = null, $page = 1) {
+	public function findChildren($query, $options) {
 		extract($this->config());
+		extract($options);
 		$primaryKey = $this->_table->primaryKey();
+		$direct = !isset($direct) ? false : $direct;
+		$order = !isset($order) ? [$left => 'ASC'] : $order;
+
+		if (!isset($for) || empty($for)) {
+			throw new \InvalidArgumentException("The 'for' key is required for find('children')");
+		}
 
 		if ($direct) {
-			return $this->_scope($this->_table->find())
-				->where([$parent => $id])
-				->all();
+			return $this->_scope($query)
+				->where([$parent => $for])
+				->order($order);
 		}
 
 		$node = $this->_scope($this->_table->find())
 			->select([$right, $left])
-			->where([$primaryKey => $id])
+			->where([$primaryKey => $for])
 			->first();
 
 		if (!$node) {
-			return false;
-		}
-
-		$order = !$order ? [$left => 'ASC'] : $order;
-		$query = $this->_scope($this->_table->find());
-
-		if ($fields) {
-			$query->select($fields);
-		}
-
-		$query->where([
-			"{$right} <" => $node->{$right},
-			"{$left} >" => $node->{$left}
-		]);
-
-		if ($limit) {
-			$query->limit($limit);
-		}
-
-		if ($page) {
-			$query->page($page);
+			return $query;
 		}
 
-		return $query->order($order)->all();
+		return $this->_scope($query)
+			->where([
+				"{$right} <" => $node->{$right},
+				"{$left} >" => $node->{$left}
+			])
+			->order($order);
 	}
 
 /**

tests/TestCase/Model/Behavior/TreeBehaviorTest.php

@@ -125,26 +125,37 @@ class TreeBehaviorTest extends TestCase {
  *
  * @return void
  */
-	public function testChildren() {
+	public function testFindChildren() {
 		$table = TableRegistry::get('MenuLinkTrees');
 		$table->addBehavior('Tree', ['scope' => ['menu' => 'main-menu']]);
 
 		// root
 		$nodeIds = [];
-		foreach ($table->children(1) as $node) {
+		$nodes = $table->find('children', ['for' => 1])
+			->all();
+		foreach ($nodes as $node) {
 			$nodeIds[] = $node->id;
 		}
 		$this->assertEquals([2, 3, 4, 5], $nodeIds);
 
 		// unexisting node
-		$this->assertEquals(false, $table->children(500));
+		$query = $table->find('children', ['for' => 500]);
+		$this->assertEquals($query, $table->find('children', ['for' => 500]));
 
 		// leaf
 		$nodeIds = [];
-		foreach ($table->children(5) as $node) {
+		$nodes = $table->find('children', ['for' => 5])->all();
+		foreach ($nodes as $node) {
 			$nodeIds[] = $node->id;
 		}
 		$this->assertEquals(0, count($nodeIds));
+
+		// direct children
+		$nodes = $table->find('children', ['for' => 1, 'direct' => true])->all();
+		foreach ($nodes as $node) {
+			$nodeIds[] = $node->id;
+		}
+		$this->assertEquals([2, 3], $nodeIds);
 	}
 
 /**
@@ -166,7 +177,8 @@ class TreeBehaviorTest extends TestCase {
 		// move inner node
 		$nodeIds = [];
 		$result = $table->moveUp(3, 1);
-		foreach ($table->children(1) as $node) {
+		$nodes = $table->find('children', ['for' => 1])->all();
+		foreach ($nodes as $node) {
 			$nodeIds[] = $node->id;
 		}
 		$this->assertEquals([3, 4, 5, 2], $nodeIds);