Question

Is it possible to define a function in the scope of a parent function and bind an argument passed through the parent function as its scope before returning it?

Here is an example:

var myObject = {
    foo: "bar"
};

var myFunction = (function() {
    return function() {
        return this.foo;
    };
}).call(myObject);

myFunction.call(myObject); // I'd like to bind myObject as this does ...

myFunction(); // ... but I'd like to do it before invoking it, without .call() or .apply()

Or another complex example, that describes what I’m trying to do:

var createMyCopy = function(original, self) {
    var copy;

    eval("copy=" + original.toString());

    console.log(copy()); // returns undefined
};

(function() {
    var self = "Hello world",
        myFunction = function() {
            return self;
        };

    console.log(myFunction()); // returns "Hello world"

    createMyCopy(myFunction);
})();

I’m trying to create a copy of a function, so that I can make changes to it without changing the original one, but I’d like to have the variables that are defined in the original one in the copy as well…

Answer 1

Do you mean like this?

var myObject = {
    foo: "bar"
};

var myFunction = (function() {
    var self = this;
    return function() {
        return self.foo;
    };
}).call(myObject);

I think you’re getting scope and context mixed up in your question.