jQuery Plugin: Adding Callback functionality

Question

I'm trying to give my plugin callback functionality, and I'd like for it to operate in a somewhat traditional way:

myPlugin({options}, function() {
    /* code to execute */
});

or

myPlugin({options}, anotherFunction());

How do I handle that parameter in the code? Is it treated as one full entity? I'm pretty sure I know where I'd place the executory code, but how do I get the code to execute? I can't seem to find a lot of literature on the topic, so thanks in advance for your help.

Answer 1

Change your plugin function to take a second parameter. Assuming that the user passes a function, that parameter can be treated as a regular function.
Note that you can also make the callback a property of the options parameter.

For example:

$.fn.myPlugin = function(options, callback) {
    ...

    if(callback)        //If the caller supplied a callback
        callback(someParam);

    ...
});

Answer 2

Just execute the callback in the plugin:

$.fn.myPlugin = function(options, callback) {
    if (typeof callback == 'function') { // make sure the callback is a function
        callback.call(this); // brings the scope to the callback
    }
};

You can also have the callback in the options object:

$.fn.myPlugin = function() {

    // extend the options from pre-defined values:
    var options = $.extend({
        callback: function() {}
    }, arguments[0] || {});

    // call the callback and apply the scope:
    options.callback.call(this);

};

Use it like this:

$('.elem').myPlugin({
    callback: function() {
        // some action
    }
});

Answer 3

I don't know if I understand your question correctly. But for the second version: This would call anotherFunction immediately.

Basically your plugin should be some kind of function that looks like this:

var myPlugin = function(options, callback) {
    //do something with options here
    //call callback
    if(callback) callback();
} 

You have to provide a function object as callback, so either function(){...} or anotherFunction (without () ).