I have a function I can't modify:
function addToMe() { doStuff(); }
Can I add to this function? Obviously this syntax is terribly wrong but it's the general idea...
function addToMe() { addToMe() + doOtherStuff(); }
Add a comment
|
1 Answer
You could store a reference to the original function, and then override it, with a function that calls back the original one, and adds the functionality you desire:
var originalFn = addToMe;
addToMe = function () {
originalFn(); // call the original function
// other stuff
};
You can do this because JavaScript functions are first-class objects.
Edit: If your function receives arguments, you should use apply to pass them to the original function:
addToMe = function () {
originalFn.apply(this, arguments); // preserve the arguments
// other stuff
};
You could also use an auto-executing function expression with an argument to store the reference of the original function, I think it is a little bit cleaner:
addToMe = (function (originalFn) {
return function () {
originalFn.apply(originalFn, arguments); // call the original function
// other stuff
};
})(addToMe); // pass the reference of the original function
answered Nov 2, 2009 at 2:51
Christian C. Salvadó
831k185 gold badges929 silver badges845 bronze badges
2 Comments
mauris
yep that's probably the simplest solution!
hugo der hungrige
You should add a second return-statement before originalFn!