apologies
getOwnPropertyDescriptor(
source,
key
)
should have been
getOwnPropertyDescriptor(
enricher,
key
)
On Sun, Apr 14, 2013 at 1:58 AM, Andrea Giammarchi <
andrea.giammar...@gmail.com> wrote:
> what I've written here:
>
> https://github.com/WebReflection/object-mixin/blob/master/src/object-mixin.js
>
> is a better proposal for the potential `Object.mixin()` in current ES6
> specs.
>
> It seems that Mixins Are Awesome and this can take most advantages from
> being a function and not only an object:
> http://webreflection.blogspot.ie/2013/04/flight-mixins-are-awesome.html
>
> AFAIK, all interfaces described in W3C such EventTarget and others could
> be also covered by this proposal ... so ... what do you think ?
>
> /*jslint browser: true, forin: true, plusplus: true, indent: 4 */
> (function(Object, mixin) {
> "use strict"; // happy linter ^_____^
>
> /* <droppable>
> * adhoc polyfill section for this purpose only
> * never use these functions outside this closure ... like ...
> ne*/var
> /*
> ^ ... you see that? only reason I chose 4 spaces indentations here :D
> also this comment ... pure quality, right ?!?! ... anyway ... */
>
> // for IE < 9 Desktop browsers
> defineProperty = Object.defineProperty ||
> function (o, k, d) {
> o[k] = d.value;
> },
> // same as above
> getOwnPropertyNames = Object.getOwnPropertyNames ||
> function (o) {
> var
> // in case the guy does not inherit from Object.prototype
> has = Object.prototype.hasOwnProperty,
> result = [],
> key;
> for (key in o) {
> // in non ES5 compliant browsers
> // there's no way to define properties
> // as non enumerable unless these are
> // there by default, like "constructor" is
> // for functions.prototype
> if (has.call(o, key)) {
> result.push(key);
> }
> }
> return result;
> },
> // again ... IE < 8
> getOwnPropertyDescriptor = Object.getOwnPropertyDescriptor ||
> function (o, k) {
> return {
> enumerable: true,
> writable: true,
> configurable: true,
> value: o[k]
> };
> };
> // </droppable>
>
> // if already defined get out of here
> // this should be
> // if (mixin in Object) return;
> // but for some reason I went for JSLint ...
> if (Object[mixin]) {
> return;
> }
> // same descriptor as other spec'd methods
> defineProperty(
> Object,
> mixin,
> {
> enumerable: false,
> writable: true,
> configurable: true,
> value: function mixin(
> target, // object to enrich with
> source // mixin object/function
> ) {
> var
> // check if source is a function
> enricher = typeof source === 'function' ?
> source.prototype : source,
> // per each own property name
> keys = getOwnPropertyNames(enricher),
> length = keys.length,
> i = 0,
> key;
> while (i < length) {
> // define it ...
> defineProperty(
> target,
> key = keys[i++],
> // ... via same property descriptor
> getOwnPropertyDescriptor(
> source,
> key
> )
> );
> }
> // if the object had no own names
> // it's quite clear the intention of the user
> // so that if a function without properties
> // is passed through this method ...
> if (!length && typeof source === 'function') {
> // this function is invoked with the target
> // as its own context
> source.apply(
> target,
> // optional arguments to initialize defaults
> // for this mixin might be accepted too
> keys.slice.call(arguments, 2)
> );
> }
> // always return the initial target
> // ignoring a possible different return
> // in latter case: consistency with this method
> return target;
> }
> }
> );
> }(Object, 'mixin'));
>
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