1 files changed, 92 insertions, 0 deletions
diff --git a/js/classes/ElggPriorityList.js b/js/classes/ElggPriorityList.js
new file mode 100644
index 000000000..b4cec5044
--- /dev/null
+++ b/js/classes/ElggPriorityList.js
@@ -0,0 +1,92 @@
+/**
+ * Priority lists allow you to create an indexed list that can be iterated through in a specific
+ * order.
+ */
+elgg.ElggPriorityList = function() {
+	this.length = 0;
+	this.priorities_ = [];
+};
+
+/**
+ * Inserts an element into the priority list at the priority specified.
+ *
+ * @param {Object} obj          The object to insert
+ * @param {Number} opt_priority An optional priority to insert at.
+ * 
+ * @return {Void}
+ */
+elgg.ElggPriorityList.prototype.insert = function(obj, opt_priority) {
+	var priority = 500;
+	if (arguments.length == 2 && opt_priority != undefined) {
+		priority = parseInt(opt_priority, 10);
+	}
+
+	priority = Math.max(priority, 0);
+
+	if (elgg.isUndefined(this.priorities_[priority])) {
+		this.priorities_[priority] = [];
+	}
+
+	this.priorities_[priority].push(obj);
+	this.length++;
+};
+
+/**
+ * Iterates through each element in order.
+ *
+ * Unlike every, this ignores the return value of the callback.
+ *
+ * @param {Function} callback The callback function to pass each element through. See
+ *                            Array.prototype.every() for details.
+ * @return {Object}
+ */
+elgg.ElggPriorityList.prototype.forEach = function(callback) {
+	elgg.assertTypeOf('function', callback);
+
+	var index = 0;
+
+	this.priorities_.forEach(function(elems) {
+		elems.forEach(function(elem) {
+			callback(elem, index++);
+		});
+	});
+
+	return this;
+};
+
+/**
+ * Iterates through each element in order.
+ *
+ * Unlike forEach, this returns the value of the callback and will break on false.
+ *
+ * @param {Function} callback The callback function to pass each element through. See
+ *                            Array.prototype.every() for details.
+ * @return {Object}
+ */
+elgg.ElggPriorityList.prototype.every = function(callback) {
+	elgg.assertTypeOf('function', callback);
+
+	var index = 0;
+
+	return this.priorities_.every(function(elems) {
+		return elems.every(function(elem) {
+			return callback(elem, index++);
+		});
+	});
+};
+
+/**
+ * Removes an element from the priority list
+ *
+ * @param {Object} obj The object to remove.
+ * @return {Void}
+ */
+elgg.ElggPriorityList.prototype.remove = function(obj) {
+	this.priorities_.forEach(function(elems) {
+		var index;
+		while ((index = elems.indexOf(obj)) !== -1) {
+			elems.splice(index, 1);
+			this.length--;
+		}
+	});
+};
+\ No newline at end of file