Changed prefixed method to return live object and added third arg to …

…bind to
Modernizr · Jan 30, 2012 · 16a056d · 16a056d · SlexAxton · Jan 30, 2012
1 parent 7efcb78
commit 16a056d
Showing 1 changed file with 128 additions and 8 deletions.
diff --git a/modernizr.js b/modernizr.js
@@ -201,6 +201,126 @@ window.Modernizr = (function( window, document, undefined ) {
       };
     }
 
+    // Taken from ES5-shim https://github.com/kriskowal/es5-shim/blob/master/es5-shim.js
+    // ES-5 15.3.4.5
+    // http://es5.github.com/#x15.3.4.5
+
+    if (!Function.prototype.bind) {
+      Function.prototype.bind = function bind(that) { // .length is 1
+        // 1. Let Target be the this value.
+        var target = this;
+        // 2. If IsCallable(Target) is false, throw a TypeError exception.
+        if (typeof target != "function") {
+            throw new TypeError(); // TODO message
+        }
+        // 3. Let A be a new (possibly empty) internal list of all of the
+        // argument values provided after thisArg (arg1, arg2 etc), in order.
+        // XXX slicedArgs will stand in for "A" if used
+        var args = slice.call(arguments, 1); // for normal call
+        // 4. Let F be a new native ECMAScript object.
+        // 11. Set the [[Prototype]] internal property of F to the standard
+        // built-in Function prototype object as specified in 15.3.3.1.
+        // 12. Set the [[Call]] internal property of F as described in
+        // 15.3.4.5.1.
+        // 13. Set the [[Construct]] internal property of F as described in
+        // 15.3.4.5.2.
+        // 14. Set the [[HasInstance]] internal property of F as described in
+        // 15.3.4.5.3.
+        var bound = function () {
+
+            if (this instanceof bound) {
+              // 15.3.4.5.2 [[Construct]]
+              // When the [[Construct]] internal method of a function object,
+              // F that was created using the bind function is called with a
+              // list of arguments ExtraArgs, the following steps are taken:
+              // 1. Let target be the value of F's [[TargetFunction]]
+              // internal property.
+              // 2. If target has no [[Construct]] internal method, a
+              // TypeError exception is thrown.
+              // 3. Let boundArgs be the value of F's [[BoundArgs]] internal
+              // property.
+              // 4. Let args be a new list containing the same values as the
+              // list boundArgs in the same order followed by the same
+              // values as the list ExtraArgs in the same order.
+              // 5. Return the result of calling the [[Construct]] internal
+              // method of target providing args as the arguments.
+
+              var F = function(){};
+              F.prototype = target.prototype;
+              var self = new F;
+
+              var result = target.apply(
+                  self,
+                  args.concat(slice.call(arguments))
+              );
+              if (Object(result) === result) {
+                  return result;
+              }
+              return self;
+
+            } else {
+              // 15.3.4.5.1 [[Call]]
+              // When the [[Call]] internal method of a function object, F,
+              // which was created using the bind function is called with a
+              // this value and a list of arguments ExtraArgs, the following
+              // steps are taken:
+              // 1. Let boundArgs be the value of F's [[BoundArgs]] internal
+              // property.
+              // 2. Let boundThis be the value of F's [[BoundThis]] internal
+              // property.
+              // 3. Let target be the value of F's [[TargetFunction]] internal
+              // property.
+              // 4. Let args be a new list containing the same values as the
+              // list boundArgs in the same order followed by the same
+              // values as the list ExtraArgs in the same order.
+              // 5. Return the result of calling the [[Call]] internal method
+              // of target providing boundThis as the this value and
+              // providing args as the arguments.
+
+              // equiv: target.call(this, ...boundArgs, ...args)
+              return target.apply(
+                  that,
+                  args.concat(slice.call(arguments))
+              );
+
+            }
+
+        };
+        // XXX bound.length is never writable, so don't even try
+        //
+        // 15. If the [[Class]] internal property of Target is "Function", then
+        // a. Let L be the length property of Target minus the length of A.
+        // b. Set the length own property of F to either 0 or L, whichever is
+        // larger.
+        // 16. Else set the length own property of F to 0.
+        // 17. Set the attributes of the length own property of F to the values
+        // specified in 15.3.5.1.
+
+        // TODO
+        // 18. Set the [[Extensible]] internal property of F to true.
+
+        // TODO
+        // 19. Let thrower be the [[ThrowTypeError]] function Object (13.2.3).
+        // 20. Call the [[DefineOwnProperty]] internal method of F with
+        // arguments "caller", PropertyDescriptor {[[Get]]: thrower, [[Set]]:
+        // thrower, [[Enumerable]]: false, [[Configurable]]: false}, and
+        // false.
+        // 21. Call the [[DefineOwnProperty]] internal method of F with
+        // arguments "arguments", PropertyDescriptor {[[Get]]: thrower,
+        // [[Set]]: thrower, [[Enumerable]]: false, [[Configurable]]: false},
+        // and false.
+
+        // TODO
+        // NOTE Function objects created using Function.prototype.bind do not
+        // have a prototype property or the [[Code]], [[FormalParameters]], and
+        // [[Scope]] internal properties.
+        // XXX can't delete prototype in pure-js.
+
+        // 22. Return F.
+        return bound;
+      };
+    }
+
     /**
      * setCss applies given styles to the Modernizr DOM node.
      */
@@ -247,10 +367,10 @@ window.Modernizr = (function( window, document, undefined ) {
      * testDOMProps is a generic DOM property test; if a browser supports
      *   a certain property, it won't return undefined for it.
      */
-    function testDOMProps( props, obj ) {
+    function testDOMProps( props, obj, elem ) {
         for ( var i in props ) {
             if ( obj[ props[i] ] !== undefined) {
-                return props[i];
+                return elem ? obj[props[i]].bind(elem) : obj[props[i]];
             }
         }
         return false;
@@ -262,7 +382,7 @@ window.Modernizr = (function( window, document, undefined ) {
      *   the element including the non-vendor prefixed one, for forward-
      *   compatibility.
      */
-    function testPropsAll( prop, prefixed ) {
+    function testPropsAll( prop, prefixed, elem ) {
 
         var ucProp  = prop.charAt(0).toUpperCase() + prop.substr(1),
             props   = (prop + ' ' + cssomPrefixes.join(ucProp + ' ') + ucProp).split(' ');
@@ -271,7 +391,7 @@ window.Modernizr = (function( window, document, undefined ) {
           return testProps(props, prefixed);
         } else {
           props = (prop + ' ' + (domPrefixes).join(ucProp + ' ') + ucProp).split(' ');
-          return testDOMProps(props, prefixed);
+          return testDOMProps(props, prefixed, elem);
         }
     }
 
@@ -445,8 +565,8 @@ window.Modernizr = (function( window, document, undefined ) {
         return ('draggable' in div) || ('ondragstart' in div && 'ondrop' in div);
     };
 
-    // Mozilla is targeting to land MozWebSocket for FF6
-    // bugzil.la/659324
+    // FIXME: Once FF10 is sunsetted, we can drop prefixed MozWebSocket
+    // bugzil.la/695635
     tests['websockets'] = function() {
         for ( var i = -1, len = cssomPrefixes.length; ++i < len; ){
           if ( window[cssomPrefixes[i] + 'WebSocket'] ){
@@ -1124,12 +1244,12 @@ window.Modernizr = (function( window, document, undefined ) {
     //     },
     //     transEndEventName = transEndEventNames[ Modernizr.prefixed('transition') ];
 
-    Modernizr.prefixed      = function(prop, obj){
+    Modernizr.prefixed      = function(prop, obj, elem){
       if(!obj) {
         return testPropsAll(prop, 'pfx');
       } else {
         // Testing DOM property e.g. Modernizr.prefixed('requestAnimationFrame', window) // 'mozRequestAnimationFrame'
-        return testPropsAll(prop, obj);
+        return testPropsAll(prop, obj, elem);
       }
     };