Is it possible to call a non-existent method on the fly and then create it?

Question

The context of this question is as follows: I've written a jQuery plugin using jQuery's recommended design pattern where you pass a string as the first parameter of you plugin to call a desired (and pre-defined) method of that is an object of your plugin method. Such as:

$("selector").php('method_name');

With my particular plugin however (which just calls PHP functions through a simple AJAX handler), I would like to provide its users with the ability to call a given backend PHP function in this manner:

$("selector").php.strlen(param); // As an example of calling the PHP strlen function

Where .strlen isn't a defined method of the .php object (or any other object). In other words is there a way to prevent JavaScript from throwing an exception and catch the name of the desired method name a user is attempting to call, when that method in fact has not been defined and does not exist?

I don't want to go about defining the method names (or interfaces) to every PHP function for obvious reasons. It would be a lot of code overhead and would be very time consuming.

Answer 1

ECMAScript Harmony supports Proxies that let you intercept property access. Unfortunately, it's not widely supported yet (Firefox 18 supports it).

var php = new Proxy({}, {
    get: function (target, name) {
        return function () {
            var args = Array.prototype.slice.call(arguments);
            alert('Here you would call ' + name + '(' + args.join(', ') + ')');
        };
    }
});

php.strlen('hello');

There was something called __noSuchMethod__ , but again, it doesn't seem to be widely supported.

Answer 2

You could wrap it in a try catch block.

try {
   $("selector").php.strlen(param);
} catch(err) {
   // do sth
}