Finished ElggPriorityList. Migrated external files to use it.

3 files changed, 241 insertions, 42 deletions

diff --git a/engine/classes/ElggPriorityList.php b/engine/classes/ElggPriorityList.php
index 39fe698da..931138106 100644
--- a/engine/classes/ElggPriorityList.php
+++ b/engine/classes/ElggPriorityList.php
@@ -26,6 +26,7 @@
  *
  *
  * // Array
+ * 
  * $pl = new ElggPriorityList();
  * $pl[] = 'Element 0';
  * $pl[-5] = 'Element -5';
@@ -45,24 +46,45 @@
  * 10 => Element 10
  *
  *
- * Collisions with priority are handled by inserting the element as close to the requested priority
- * as possible.
+ * Collisions with priority are handled by default differently in the OOP and the array interfaces.
+ * 
+ * If using the OOP interface, the default is to insert the element as close to the requested
+ * priority as possible.
  *
  * $pl = new ElggPriorityList();
- * $pl[5] = 'Element 5';
- * $pl[5] = 'Colliding element 5';
- * $pl[5] = 'Another colliding element 5';
+ * $pl->add('Element 5', 5);
+ * $pl->add('Colliding element 5', 5);
+ * $pl->add('Another colliding element 5', 5);
  *
  * var_dump($pl->getElements());
  *
  * Yields:
- *
  * array(
  *	5 => 'Element 5',
  *	6 => 'Colliding element 5',
  *	7 => 'Another colliding element 5'
  * )
  *
+ * If using the array interface, elements are added at exactly the priority, displacing other
+ * elements if necessary. This behavior is also available by passing true as the 3rd argument to
+ * ->add():
+ *
+ * $pl = new ElggPriorityList();
+ * $pl[5] = 'Element 5';
+ * $pl[6] = 'Element 6';
+ * $pl[5] = 'Colliding element 5'; // shifts the previous two up by one
+ * $pl->add('Another colliding element 5', 5, true); // shifts the previous three up by one
+ *
+ * var_dump($pl->getElements());
+ *
+ * Yields:
+ * array(
+ *	5 => 'Another colliding element 5',
+ *	6 => 'Colliding element 5',
+ *	7 => 'Element 5',
+ *	8 => 'Element 6'
+ * )
+ *
  * @package Elgg.Core
  * @subpackage Helpers
  */
@@ -101,16 +123,21 @@ class ElggPriorityList
 	 *                        maintains its priority and the new element is to the next available
 	 *                        slot, taking into consideration all previously registered elements.
 	 *                        Negative elements are accepted.
-	 * @return int            The priority the element was added at.
+	 * @param bool  $exact    If true, will put the element at exactly the priority specified, displacing
+	 *                        other elements.
+	 * @return int            The priority of the added element.
 	 */
-	public function add($element, $priority = null) {
+	public function add($element, $priority = null, $exact = false) {
 		if ($priority !== null && !is_numeric($priority)) {
 			return false;
+		} elseif ($exact) {
+			$this->shiftElementsSegment($priority);
 		} else {
 			$priority = $this->getNextPriority($priority);
 		}
 
 		$this->elements[$priority] = $element;
+		$this->sorted = false;
 		return $priority;
 	}
 
@@ -134,6 +161,32 @@ class ElggPriorityList
 	}
 
 	/**
+	 * Move an existing element to a new priority.
+	 *
+	 * @param int  $current_priority
+	 * @param int  $new_priority
+	 * @param bool $exact
+	 * @return bool
+	 */
+	public function move($current_priority, $new_priority, $exact = false) {
+		$current_priority = (int) $current_priority;
+		$new_priority = (int) $new_priority;
+
+		if (!isset($this->elements[$current_priority])) {
+			return false;
+		}
+
+		if ($current_priority == $new_priority) {
+			return true;
+		}
+
+		$element = $this->elements[$current_priority];
+		unset($this->elements[$current_priority]);
+
+		return $this->add($element, $new_priority, $exact);
+	}
+
+	/**
 	 * Returns the elements
 	 *
 	 * @param type $elements
@@ -186,6 +239,29 @@ class ElggPriorityList
 	}
 
 	/**
+	 * Shift a segment of elements starting at $index up by one until the end of the array or
+	 * there's a gap in the indexes. This produces a space at $index to insert a new element.
+	 *
+	 * @param type $index The index to start
+	 * @return array
+	 */
+	private function shiftElementsSegment($index) {
+		$index = (int) $index;
+		// @todo probably a better way.
+		$replace_elements = array();
+		while (isset($this->elements[$index])) {
+			$replace_elements[$index + 1] = $this->elements[$index];
+			unset($this->elements[$index]);
+			$index++;
+		}
+
+		// insert old ones
+		foreach ($replace_elements as $index => $element) {
+			$this->elements[$index] = $element;
+		}
+	}
+
+	/**
 	 * Returns the next priority available.
 	 *
 	 * @param int $near Make the priority as close to $near as possible.
@@ -295,7 +371,9 @@ class ElggPriorityList
 	}
 
 	public function offsetSet($offset, $value) {
-		return $this->add($value, $offset);
+		// for $pl[] = 'New element'
+		$exact = ($offset !== null);
+		return $this->add($value, $offset, $exact);
 	}
 
 	public function offsetUnset($offset) {
diff --git a/engine/lib/elgglib.php b/engine/lib/elgglib.php
index cb736f418..b6b603e79 100644
--- a/engine/lib/elgglib.php
+++ b/engine/lib/elgglib.php
@@ -172,7 +172,7 @@ function forward($location = "", $reason = 'system') {
  * @return bool
  * @since 1.8.0
  */
-function elgg_register_js($name, $url, $location = 'head', $priority = 500) {
+function elgg_register_js($name, $url, $location = 'head', $priority = null) {
 	return elgg_register_external_file('js', $name, $url, $location, $priority);
 }
 
@@ -225,7 +225,7 @@ function elgg_get_loaded_js($location = 'head') {
  * @return bool
  * @since 1.8.0
  */
-function elgg_register_css($name, $url, $priority = 500) {
+function elgg_register_css($name, $url, $priority = null) {
 	return elgg_register_external_file('css', $name, $url, 'head', $priority);
 }
 
@@ -278,7 +278,7 @@ function elgg_get_loaded_css() {
  * @return bool
  * @since 1.8.0
  */
-function elgg_register_external_file($type, $name, $url, $location, $priority = 500) {
+function elgg_register_external_file($type, $name, $url, $location, $priority = null) {
 	global $CONFIG;
 
 	if (empty($name) || empty($url)) {
@@ -292,26 +292,35 @@ function elgg_register_external_file($type, $name, $url, $location, $priority =
 		$CONFIG->externals = array();
 	}
 
-	if (!isset($CONFIG->externals[$type])) {
-		$CONFIG->externals[$type] = array();
+	if (!$CONFIG->externals[$type] instanceof ElggPriorityList) {
+		$CONFIG->externals[$type] = new ElggPriorityList();
 	}
 
 	$name = trim(strtolower($name));
+	$priority = max((int)$priority, 0);
 
-	if (isset($CONFIG->externals[$type][$name])) {
-		// update a registered item
-		$item = $CONFIG->externals[$type][$name];
+	$index = elgg_get_external_file_priority($name, $type);
+
+	if ($index !== false) {
+		// updating a registered item
+		$item = $CONFIG->externals[$type][$index];
+		$item->url = $url;
+		$item->location = $location;
 
+		// remove old saved priority
+		elgg_remove_external_file_priority($name, $type);
+		$priority = $CONFIG->externals[$type]->move($index, $priority);
 	} else {
 		$item = new stdClass();
 		$item->loaded = false;
-	}
+		$item->url = $url;
+		$item->location = $location;
 
-	$item->url = $url;
-	$item->priority = max((int)$priority, 0);
-	$item->location = $location;
+		$priority = $CONFIG->externals[$type]->add($item, $priority);
+	}
 
-	$CONFIG->externals[$type][$name] = $item;
+	// save priority map so we can update if added again
+	elgg_save_external_file_priority($priority, $name, $type);
 
 	return true;
 }
@@ -332,14 +341,17 @@ function elgg_unregister_external_file($type, $name) {
 		return false;
 	}
 
-	if (!isset($CONFIG->externals[$type])) {
+	if (!$CONFIG->externals[$type] instanceof ElggPriorityList) {
 		return false;
 	}
 
 	$name = trim(strtolower($name));
 	
-	if (array_key_exists($name, $CONFIG->externals[$type])) {
-		unset($CONFIG->externals[$type][$name]);
+	$priority = elgg_get_external_file_priority($name, $type);
+
+	if ($priority !== false) {
+		elgg_remove_external_file_priority($name, $type);
+		unset($CONFIG->externals[$type][$priority]);
 		return true;
 	}
 
@@ -362,24 +374,75 @@ function elgg_load_external_file($type, $name) {
 		$CONFIG->externals = array();
 	}
 
-	if (!isset($CONFIG->externals[$type])) {
-		$CONFIG->externals[$type] = array();
+	if (!$CONFIG->externals[$type] instanceof ElggPriorityList) {
+		$CONFIG->externals[$type] = new ElggPriorityList();
 	}
 
 	$name = trim(strtolower($name));
 
-	if (isset($CONFIG->externals[$type][$name])) {
+	$priority = elgg_get_external_file_priority($name, $type);
+
+	if ($priority !== false) {
 		// update a registered item
-		$CONFIG->externals[$type][$name]->loaded = true;
+		$CONFIG->externals[$type][$priority]->loaded = true;
 	} else {
 		$item = new stdClass();
 		$item->loaded = true;
 		$item->url = '';
 		$item->location = '';
-		$item->priority = 500;
 
-		$CONFIG->externals[$type][$name] = $item;
+		$priority = $CONFIG->externals[$type]->add($item);
+		elgg_save_external_file_priority($priority, $name, $type);
+	}
+}
+
+/**
+ * Gets the priority of an external by name and type.
+ *
+ * @param type $name
+ * @param type $type
+ * @return type 
+ */
+function elgg_get_external_file_priority($name, $type) {
+	global $CONFIG;
+
+	if (!isset($CONFIG->externals_priorities[$type][$name])) {
+		return false;
+	}
+
+	return $CONFIG->externals_priorities[$type][$name];
+}
+
+function elgg_save_external_file_priority($priority, $name, $type) {
+	global $CONFIG;
+
+	if (!isset($CONFIG->externals_priorities)) {
+		$CONFIG->externals_priorities = array();
+	}
+	
+	if (!isset($CONFIG->externals_priorities[$type])) {
+		$CONFIG->externals_priorities[$type] = array();
+	}
+
+	$CONFIG->externals_priorities[$type][$name] = $priority;
+
+	return true;
+}
+
+function elgg_remove_external_file_priority($name, $type) {
+	global $CONFIG;
+	
+	if (!isset($CONFIG->externals_priorities)) {
+		$CONFIG->externals_priorities = array();
 	}
+
+	if (!isset($CONFIG->externals_priorities[$type])) {
+		$CONFIG->externals_priorities[$type] = array();
+	}
+
+	unset($CONFIG->externals_priorities[$type][$name]);
+
+	return true;
 }
 
 /**
@@ -394,13 +457,12 @@ function elgg_load_external_file($type, $name) {
 function elgg_get_loaded_external_files($type, $location) {
 	global $CONFIG;
 
-	if (isset($CONFIG->externals) && isset($CONFIG->externals[$type])) {
-		$items = array_values($CONFIG->externals[$type]);
+	if (isset($CONFIG->externals) && $CONFIG->externals[$type] instanceof ElggPriorityList) {
+		$items = $CONFIG->externals[$type]->getElements();
 
 		$callback = "return \$v->loaded == true && \$v->location == '$location';";
 		$items = array_filter($items, create_function('$v', $callback));
 		if ($items) {
-			usort($items, create_function('$a,$b','return $a->priority >= $b->priority;'));
 			array_walk($items, create_function('&$v,$k', '$v = $v->url;'));
 		}
 		return $items;
diff --git a/engine/tests/api/helpers.php b/engine/tests/api/helpers.php
index 033970359..cceb762be 100644
--- a/engine/tests/api/helpers.php
+++ b/engine/tests/api/helpers.php
@@ -31,6 +31,7 @@ class ElggCoreHelpersTest extends ElggCoreUnitTest {
 
 		global $CONFIG;
 		unset($CONFIG->externals);
+		unset($CONFIG->externals_priorities);
 	}
 
 	/**
@@ -106,7 +107,9 @@ class ElggCoreHelpersTest extends ElggCoreUnitTest {
 		// specify name
 		$result = elgg_register_js('key', 'http://test1.com', 'footer');
 		$this->assertTrue($result);
-		$this->assertIdentical('http://test1.com', $CONFIG->externals['js']['key']->url);
+		$this->assertTrue(isset($CONFIG->externals_priorities['js']['key']));
+		$index = $CONFIG->externals_priorities['js']['key'];
+		$this->assertIdentical('http://test1.com', $CONFIG->externals['js'][$index]->url);
 
 		// send a bad url
 		$result = @elgg_register_js('bad');
@@ -122,7 +125,9 @@ class ElggCoreHelpersTest extends ElggCoreUnitTest {
 		// specify name
 		$result = elgg_register_css('key', 'http://test1.com');
 		$this->assertTrue($result);
-		$this->assertIdentical('http://test1.com', $CONFIG->externals['css']['key']->url);
+		$this->assertTrue(isset($CONFIG->externals_priorities['css']['key']));
+		$index = elgg_get_external_file_priority('css', 'key');
+		$this->assertIdentical('http://test1.com', $CONFIG->externals['css'][$index]->url);
 	}
 
 	/**
@@ -140,7 +145,13 @@ class ElggCoreHelpersTest extends ElggCoreUnitTest {
 
 		$result = elgg_unregister_js('id1');
 		$this->assertTrue($result);
-		@$this->assertNULL($CONFIG->externals['js']['head']['id1']);
+
+		$js = $CONFIG->externals['js'];
+		$elements = $js->getElements();
+		$this->assertFalse(isset($CONFIG->externals_priorities['js']['id1']));
+		foreach ($elements as $element) {
+			$this->assertFalse($element->name == 'id1');
+		}
 
 		$result = elgg_unregister_js('id1');
 		$this->assertFalse($result);
@@ -148,7 +159,15 @@ class ElggCoreHelpersTest extends ElggCoreUnitTest {
 		$this->assertFalse($result);
 
 		$result = elgg_unregister_js('id2');
-		$this->assertIdentical($urls['id3'], $CONFIG->externals['js']['id3']->url);
+		$elements = $js->getElements();
+		$this->assertFalse(isset($CONFIG->externals_priorities['js']['id2']));
+		foreach ($elements as $element) {
+			$this->assertFalse($element->name == 'id2');
+		}
+
+		$this->assertTrue(isset($CONFIG->externals_priorities['js']['id3']));
+		$priority = $CONFIG->externals_priorities['js']['id3'];
+		$this->assertIdentical($urls['id3'], $CONFIG->externals['js'][$priority]->url);
 	}
 
 	/**
@@ -361,18 +380,19 @@ class ElggCoreHelpersTest extends ElggCoreUnitTest {
 
 	public function testElggPriorityListArrayAccess() {
 		$pl = new ElggPriorityList();
+		
 		$pl[] = 'Test element 0';
 		$pl[-10] = 'Test element -10';
 		$pl[-1] = 'Test element -1';
 		$pl[] = 'Test element 1';
 		$pl[5] = 'Test element 5';
-		$pl[0] = 'Test element collision with 0 (should be 2)';
+		$pl[0] = 'Test element collision with 0';
 
 		$elements = array(
 			-1 => 'Test element -1',
-			0 => 'Test element 0',
-			1 => 'Test element 1',
-			2 => 'Test element collision with 0 (should be 2)',
+			0 => 'Test element collision with 0',
+			1 => 'Test element 0',
+			2 => 'Test element 1',
 			5 => 'Test element 5',
 		);
 
@@ -441,4 +461,43 @@ class ElggCoreHelpersTest extends ElggCoreUnitTest {
 
 		$this->assertIdentical($elements_sorted_string, $test_elements);
 	}
+
+	function testElggPriorityListShiftElementsSegment() {
+		$elements = array(
+			0 => 'Element 0',
+			1 => 'Element 1',
+			2 => 'Element 2',
+			4 => 'Element 4',
+		);
+
+		$pl = new ElggPriorityList($elements);
+
+		// add a new element directly at 1.
+		$pl->add('New Element', 1, true);
+
+		$elements_sorted = array(
+			0 => 'Element 0',
+			1 => 'New Element',
+			2 => 'Element 1',
+			3 => 'Element 2',
+			4 => 'Element 4',
+		);
+
+		$test_elements = $pl->getElements();
+		$this->assertIdentical($elements_sorted, $test_elements);
+
+		$pl->add('New Element 10', 10, true);
+
+		$elements_sorted = array(
+			0 => 'Element 0',
+			1 => 'New Element',
+			2 => 'Element 1',
+			3 => 'Element 2',
+			4 => 'Element 4',
+			10 => 'New Element 10'
+		);
+
+		$test_elements = $pl->getElements();
+		$this->assertIdentical($elements_sorted, $test_elements);
+	}
 }
\ No newline at end of file