Question

In .NET you can add multiple handlers to an event which an object declares as an event.

What is the recommended way for handling this in JavaScript for non-DOM objects?

i.e. I have an object:

var ProblemDomainObj = {} ;
ProblemDomainObj.Changed = function() {} ;
ProblemDomainObj.Data = { somedata : "initialized" } ;
ProblemDomainObj.Operate = function (newdata) {
    if (newdata != somedata && ProblemDomainObj.IsValid(newdata)) {
        somedata = newdata;
        ProblemDomainObj.Changed();
    }
} ;

Now other objects may want to register to know that the data has changed and each want to do something like this:

ProblemDomainObj.Changed += function() {
     /* Do stuff to reflect the object model changes */
} ;

Where each gets to register their handler without overwriting the other.

Then some object will call ProblemDomainObj.Operate(foo); and all those who have subscribed will get notified.

I have found the documentation in jQuery for http://api.jquery.com/on/ but it seems to relate to DOM events like onclick. None of this would necessarily be related to the DOM.

Answer 1

jQuery works great on regular objects as well: http://jsfiddle.net/gMNkg/.

var ProblemDomainObj = {};

ProblemDomainObj.Data = { somedata : "initialized" };

ProblemDomainObj.Operate = function () {
    $(ProblemDomainObj).trigger("foo"); // run bound functions
};


// bind 2 functions

$(ProblemDomainObj).on("foo", function() {
    alert(123);
});

$(ProblemDomainObj).on("foo", function() {
    alert(456);
});


ProblemDomainObj.Operate();