1 files changed, 97 insertions, 0 deletions
diff --git a/pyload/web/app/scripts/utils/lazyRequire.js b/pyload/web/app/scripts/utils/lazyRequire.js
new file mode 100644
index 000000000..96c07aa24
--- /dev/null
+++ b/pyload/web/app/scripts/utils/lazyRequire.js
@@ -0,0 +1,97 @@
+// Define the module.
+define(
+	[
+		'require', 'underscore'
+	],
+	function( require, _ ){
+        'use strict';
+
+
+		// Define the states of loading for a given set of modules
+		// within a require() statement.
+		var states = {
+			unloaded: 'UNLOADED',
+			loading: 'LOADING',
+			loaded: 'LOADED'
+		};
+
+
+		// Define the top-level module container. Mostly, we're making
+		// the top-level container a non-Function so that users won't
+		// try to invoke this without calling the once() method below.
+		var lazyRequire = {};
+
+
+		// I will return a new, unique instance of the requrieOnce()
+		// method. Each instance will only call the require() method
+		// once internally.
+		lazyRequire.once = function(){
+
+			// The modules start in an unloaded state before
+			// requireOnce() is invoked by the calling code.
+			var state = states.unloaded;
+            var args;
+
+			var requireOnce = function(dependencies, loadCallback ){
+
+				// Use the module state to determine which method to
+				// invoke (or just to ignore the invocation).
+				if (state === states.loaded){
+					loadCallback.apply(null, args);
+
+				// The modules have not yet been requested - let's
+				// lazy load them.
+				} else if (state !== states.loading){
+
+					// We're about to load the modules asynchronously;
+					// flag the interim state.
+					state = states.loading;
+
+					// Load the modules.
+					require(
+						dependencies,
+						function(){
+
+                            args = arguments;
+							loadCallback.apply( null, args );
+                            state = states.loaded;
+
+
+						}
+					);
+
+				// RequireJS is currently loading the modules
+				// asynchronously, but they have not finished
+				// loading yet.
+				} else {
+
+					// Simply ignore this call.
+					return;
+
+				}
+
+			};
+
+			// Return the new lazy loader.
+			return( requireOnce );
+
+		};
+
+
+		// -------------------------------------------------- //
+		// -------------------------------------------------- //
+
+        // Set up holder for underscore
+        var instances = {};
+        _.requireOnce = function(dependencies, loadCallback) {
+            if (!_.has(instances, dependencies))
+                instances[dependencies] = lazyRequire.once();
+
+            return instances[dependencies](dependencies, loadCallback);
+        };
+
+
+		// Return the module definition.
+		return( lazyRequire );
+	}
+);
+\ No newline at end of file