Fixing $.proxy to work like (and use) Function.prototype.bind (ticket #7783)

http://bugs.jquery.com/ticket/7783

1 files changed, 30 insertions, 19 deletions

diff --git a/src/core.js b/src/core.js
index 346e52d70..74ec4ea03 100644
--- a/src/core.js
+++ b/src/core.js
@@ -740,31 +740,42 @@ jQuery.extend({
 	// A global GUID counter for objects
 	guid: 1,
 
-	proxy: function( fn, proxy, thisObject ) {
-		if ( arguments.length === 2 ) {
-			if ( typeof proxy === "string" ) {
-				thisObject = fn;
-				fn = thisObject[ proxy ];
-				proxy = undefined;
-
-			} else if ( proxy && !jQuery.isFunction( proxy ) ) {
-				thisObject = proxy;
-				proxy = undefined;
-			}
+	// Bind a function to a context, optionally partially applying any
+	// arguments.
+	proxy: function( fn, context ) {
+		var args, proxy;
+
+		// Quick check to determine if target is callable, in the spec
+		// this throws a TypeError, but we will just return undefined.
+		if ( ! jQuery.isFunction( fn ) ) {
+			return undefined;
 		}
 
-		if ( !proxy && fn ) {
-			proxy = function() {
-				return fn.apply( thisObject || this, arguments );
-			};
+		if ( jQuery.isFunction( Function.prototype.bind ) ) {
+			// Native bind
+			args = slice.call( arguments, 1 );
+			proxy = Function.prototype.bind.apply( fn, args );
+		} else {
+			// Simulated bind
+			args = slice.call( arguments, 2 );
+			if ( args.length ) {
+				proxy = function() {
+					return arguments.length ?
+						fn.apply( context, args.concat( slice.call( arguments ) ) ) :
+						fn.apply( context, args );
+				};
+			} else {
+				proxy = function() {
+					return arguments.length ?
+						fn.apply( context, arguments ) :
+						fn.call( context );
+				};
+			}
 		}
 
 		// Set the guid of unique handler to the same of original handler, so it can be removed
-		if ( fn ) {
-			proxy.guid = fn.guid = fn.guid || proxy.guid || jQuery.guid++;
-		}
+		proxy.guid = fn.guid = fn.guid || proxy.guid || jQuery.guid++;
 
-		// So proxy can be declared as an argument
 		return proxy;
 	},