javascript - Is there a way to inject a try catch inside a function?

Question

Maybe some of you know about AOP, in some languages using AOP can lead you to be able to inject code after, before, or while a method is executing,etc.

What I want is to apply the same in Javascript, I am currently working on a massive app which has more than 300 ajax calls, and every time I need to do some change on the catch statement on them, I have to modify them one by one which is very tedious.

What I want to do is something like :

functionName.before("try {")

functionName.after("} catch(ex){
//dostuff
}")

Is it possible? I know there are things like .call, or the arguments object inside every function..which seem pretty meta-function (AOP) functionalities.

Answer 1

Not with before and after, but a wrap will work:

Function.prototype.wrapTry = function(handle) {
    var fn = this;
    return function() {
        try {
            return fn.apply(this, arguments);
        } catch(e) {
            return handle(e);
        }
    };
};

Then use it like

var safeFunction = functionName.wrapTry(doStuff);