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How do I reference an anonymous JavaScript function?

I am trying to call a page method using jQuery's "attached" event function in which I like to use a closure to make the local event local like below, but the page method calls declare multiple "error" functions and I would like to use one function to all of them. If in the code below I was handling the error and had no time to keep up, how could I use my single anonymous handler for all three error functions?

        $(":button").click(function () {
            var button = this;
            PageMethods.DoIt(
                function (a, b, c) {
                    alert(button);
                });
        });

This example executes an anonymous function for the success callback. There is only one of them. If I was going through the error callback, how could I use the (e, c, t) function for all 3 error callbacks?

ADDED: What I would like to do here makes an AJAX call whenever the user clicks a toggle button (checkbox), but for better performance I want to immediately toggle the state of the button and only "unbind" it if the AJAX call fails.

Now, in the client side event handler click()

, I would like to use anonymous functions inside the scope of click()' so that the functions have access to the

this event argument, but I don't want to 'declare' three functions for the

onTimeout ,

onError of the , and 'onAbort

arguments of the PageMethods.MyFunction function. if I declare a named function outside of a click handler, it no longer has access to the 'this' parameter of the event handler click()

.

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6 answers


I think you can put a named variable in front of it, like:

var myFunction = function(a, b, c) { ...



It was awhile I didn't, but you can try.

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If your goal is to keep this function out of the global scope, then use the module template :



(function() {
  function asplode() {
    alert('Your head asplode.');
  }

  $('body').click(asplode);
})();
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You must assign the anonymous function to the variable with var

(always use var

, otherwise the variable will get global scope, which can lead to unexpected results (for example, never declare the variable i

globally)). This is the only way to reference it:

var myFunction = function (a, b, c) {
    /* tum de dum */
};  // don't forget this semicolon

Then you can use this function in different places:

$(":button").click(myFunction);
/* don't put braces after the function name when referencing it,
   else it will be called immediately */

More information on function expressions and function declarations can be found in the article Named Function Expressions, Demystified .

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You can not. The whole point of anonymous function is that it has no name and therefore cannot be specified. (In fact, "anonymous" is basically the Greek word for "unnamed".)

If you want to refer to it, you need to give it a name.

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Inside an anonymous function, you can refer to it like arguments.callee

(this is achieved by anonymous recursion).

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If I understand correctly what you want to do, you can do it like this:

    function handler(a, b, c) {
        alert(this); // button
    }

    $(":button").click(function () {
        var button = this;
        PageMethods.DoIt(function () {
            handler.call(button, a, b, c);
        });
    });
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