weixin_33671935 2014-07-07 18:18 采纳率: 0%
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正确使用绑定的方式

What is the most correct way of using Bind. I have used like this and it is working but interested in finding the best possible option

ObjectProcessor = function (pathList) {
    this.data = null;
}
ObjectProcessor.prototype = {
    callServer: function () {
        ajaxObject.Get("api/Path", this.callReceive.bind(this), null, this.callError.bind(this), this.callComplete.bind(this));
    },
    callReceive: function (source) {

        this.data = source;
    },
    callComplete: function (source) {
        // do something
    },
    callError: function (source) {
        // Show Error
    }
};
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  • weixin_33696106 2014-07-07 19:01
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    Use bind when you need a new instance of a function whose this value is explicitly set to whatever you passed in with the bind() call.

    ECMAScript 5 defines an additional method called bind(). The bind() method creates a new function instance whose this value is bound to the value that was passed into bind(). (Zakas, Professional JavaScript for Web Developers, 3rd ed., 146).

    The main advantage seems to be using bind() in place of closures where multiple closures would make the code hard to read. See p. 738 "Function Binding" in Zakas for more. Briefly,

    Function binding involves creating a function that calls another function with a specific this value and with specific arguments. This technique is often used in conjunction with callbacks and event handlers to preserve code execution context while passing functions around as variables. (Zakas, 738)

    Bound functions are useful whenever a function pointer must be passed as a value and that function needs to be executed in a particular context. They are most commonly used for event handlers and with setTimeout() and setInterval(). However, bound functions have more overhead than regular functions — they require more memory and are slightly slower because of multiple function calls — so it’s best to use them only when necessary. (Zakas, 740-41)

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