Enhancing App::build() to allow appending paths. Closes #1680

lib/Cake/Core/App.php

@@ -62,6 +62,27 @@
  */
 class App {
 
+/**
+ * Append paths
+ *
+ * @constant APPEND
+ */
+	const APPEND = 'append';
+
+/**
+ * Prepend paths
+ *
+ * @constant PREPEND
+ */
+	const PREPEND = 'prepend';
+
+/**
+ * Reset paths instead of merging
+ *
+ * @constant RESET
+ */
+	const RESET = true;
+
 /**
  * List of object types and their properties
  *
@@ -222,15 +243,15 @@ class App {
  *
  * `App::build(array(Model' => array('/a/full/path/to/models/'))); will setup a new search path for the Model package`
  *
- * `App::build(array('Model' => array('/path/to/models/')), true); will setup the path as the only valid path for searching models`
+ * `App::build(array('Model' => array('/path/to/models/')), App::RESET); will setup the path as the only valid path for searching models`
  *
- * `App::build(array('View/Helper' => array('/path/to/models/', '/another/path/))); will setup multiple search paths for helpers`
+ * `App::build(array('View/Helper' => array('/path/to/helpers/', '/another/path/))); will setup multiple search paths for helpers`
  *
  * @param array $paths associative array with package names as keys and a list of directories for new search paths
- * @param boolean $reset true will set paths, false merges paths [default] false
+ * @param mixed $mode App::RESET will set paths, App::APPEND with append paths, App::PREPEND will prepend paths, [default] App::PREPEND
  * @return void
  */
-	public static function build($paths = array(), $reset = false) {
+	public static function build($paths = array(), $mode = App::PREPEND) {
 		if (empty(self::$__packageFormat)) {
 			self::$__packageFormat = array(
 				'Model' => array(
@@ -296,7 +317,7 @@ class App {
 			);
 		}
 
-		if ($reset == true) {
+		if ($mode === App::RESET) {
 			foreach ($paths as $type => $new) {
 				if (!empty(self::$legacy[$type])) {
 					$type = self::$legacy[$type];
@@ -329,7 +350,11 @@ class App {
 			}
 
 			if (!empty($paths[$type])) {
-				$path = array_merge((array)$paths[$type], self::$__packages[$type]);
+				if ($mode === APP::PREPEND) {
+					$path = array_merge((array)$paths[$type], self::$__packages[$type]);
+				} else {
+					$path = array_merge(self::$__packages[$type], (array)$paths[$type]);
+				}
 			} else {
 				$path = self::$__packages[$type];
 			}

lib/Cake/tests/Case/Core/AppTest.php

@@ -22,9 +22,7 @@ class AppImportTest extends CakeTestCase {
 		$this->assertEqual($expected, $old);
 
 		App::build(array('Model' => array('/path/to/models/')));
-
 		$new = App::path('Model');
-
 		$expected = array(
 			'/path/to/models/',
 			APP . 'Model' . DS,
@@ -32,6 +30,36 @@ class AppImportTest extends CakeTestCase {
 		);
 		$this->assertEqual($expected, $new);
 
+		App::build();
+		App::build(array('Model' => array('/path/to/models/')), APP::APPEND);
+		$new = App::path('Model');
+		$expected = array(
+			APP . 'Model' . DS,
+			APP . 'models' . DS,
+			'/path/to/models/'
+		);
+		$this->assertEqual($expected, $new);
+
+		App::build();
+		App::build(array(
+			'Model' => array('/path/to/models/'),
+			'Controller' => array('/path/to/controllers/'),
+		), APP::APPEND);
+		$new = App::path('Model');
+		$expected = array(
+			APP . 'Model' . DS,
+			APP . 'models' . DS,
+			'/path/to/models/'
+		);
+		$this->assertEqual($expected, $new);
+		$new = App::path('Controller');
+		$expected = array(
+			APP . 'Controller' . DS,
+			APP . 'controllers' . DS,
+			'/path/to/controllers/'
+		);
+		$this->assertEqual($expected, $new);
+
 		App::build(); //reset defaults
 		$defaults = App::path('Model');
 		$this->assertEqual($old, $defaults);
@@ -152,7 +180,7 @@ class AppImportTest extends CakeTestCase {
 		);
 		$this->assertEqual($expected, $old);
 
-		App::build(array('Model' => array('/path/to/models/')), true);
+		App::build(array('Model' => array('/path/to/models/')), App::RESET);
 
 		$new = App::path('Model');
 
@@ -210,7 +238,7 @@ class AppImportTest extends CakeTestCase {
 			'View' => App::core('View'),
 			'Model' => App::core('Model'),
 			'View/Helper' => App::core('View/Helper'),
-		), true);
+		), App::RESET);
 		$result = App::objects('behavior', null, false);
 		$this->assertTrue(in_array('TreeBehavior', $result));
 		$result = App::objects('Model/Behavior', null, false);
@@ -623,7 +651,7 @@ class AppImportTest extends CakeTestCase {
 		App::build(array(
 			'plugins' => array(LIBS . 'tests' . DS . 'test_app' . DS . 'plugins' . DS),
 			'vendors' => array(LIBS . 'tests' . DS . 'test_app' . DS . 'vendors'. DS),
-		), true);
+		), App::RESET);
 
 		ob_start();
 		$result = App::import('Vendor', 'css/TestAsset', array('ext' => 'css'));
@@ -679,7 +707,7 @@ class AppImportTest extends CakeTestCase {
 		App::build(array(
 			'libs' => array(LIBS . 'tests' . DS . 'test_app' . DS . 'libs' . DS),
 			'plugins' => array(LIBS . 'tests' . DS . 'test_app' . DS . 'plugins' . DS)
-		), true);
+		), App::RESET);
 
 		$this->assertFalse(class_exists('CustomLibClass', false));
 		App::uses('CustomLibClass', 'TestPlugin.Custom/Package');