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I need generic javascript "wait for a function to be available"

I found this great snippet. Make my account text wait for other scripts to load , which shows me how to wait for the function to be available before calling it.

I currently have this local code in my script that I created together that works for me

waitForFnc();

function waitForFnc() {
    if (typeof Portal.Management_Init == "undefined") {
        window.setTimeout(waitForFnc, 50);
    }
    else {
        Portal.Management_Init();
    }
}

However, I would like to write a generic version of "waitForFnc" as I need to do the same in several places. Sort of

waitForFnc(Portal.Management_Init);

function waitForFnc(fnc) {
    if (typeof fnc == "undefined") {
        window.setTimeout(waitForFnc(fnc), 50);
    }
    else {
       fnc();
    }
}

where I pass the name of the function in which it is called when it becomes available. The above code does not work, but I'm not sure how to resolve it.

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4 answers

, . waitForFnc() , Portal , null. , , , eval() * gasp *

, , .

function waitForFn(fnName, args){
    var fn;
    try{
        eval("fn = " + fnName);
        if(fn){
            fn.apply(null, args);
        }else{
            setTimeout(function(){waitForFn(fnName, args);}, 50);
        }
    }catch(e){
        setTimeout(function(){waitForFn(fnName, args);}, 50);
    }
}

waitForFn("Portal.Management_Init", [arg0, arg1]);
+2

, : window.setTimeout(waitForFnc(fnc), 50);, "waitForFnc" , -. .

:

window.setTimeout(function() {waitForFnc(fnc);}, 50);

, , :

var myFunc = function() {
    waitForFnc(fnc);
};

, . "setTimeout":

window.setTimeout(myFunc, 50);

"setTimeout" 50 . , waitForFnc(fnc).

+3

In the code, replace:

window.setTimeout(waitForFnc(fnc), 50);

with closure:

window.setTimeout(function() {waitForFnc(fnc)}, 50);

But may I ask, why do you need such a strange code? I would rather have an API that allows you to register a callback:

Portal.onManagementInitAvailable(fn);
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Depending on what you download, you can use require.js to take care of this for you; which is mostly for him: http://requirejs.org/docs/why.html#9

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