dojo.behavior

Authors: Peter Higgins
Nikolai Onken
Developers:?-
since:V?

A very simple, lightweight mechanism for applying code to existing documents, based around dojo.query for node selection, and a simple two-command API: dojo.behavior.add() and dojo.behavior.apply();

Usage

To use, simply require in the dojo.behavior module, after dojo.js is loaded:

Then, define a "behavior". This behavior is just an object, with a lot of special tokens. They work by selecting nodes using a CSS3 selector.

As a shorthand, if a function is passed (instead of an object) to a selector, it is assumed to be the found: function:

require(["dojo/behavior"], function(behavior){
    behavior.add({
        "#someId": function(n){
            // we found id="someId"
            console.log(n);
        }
    });
    behavior.apply();
});

Behaviors with events

Beyond simple application, we can bind selectors to Dom Events, and more, using an Object hash. Simply pass the selector and object with named events, and functions as handlers.

require(["dojo/behavior"], function(behavior){
    var myBehavior = {
       // all <a class="noclick"></a> nodes:
       "a.noclick" : {
            // event names become event connections:
            onclick: function(e){
               e.preventDefault(); // stop the default event handler
               console.log('clicked! ', e.target);
            }
        },
        // all <span> nodes
        "span" : {
            // for each:
            found: function(n){
                console.log('found', n);
            }
         }
    };
    behavior.add(myBehavior);
    behavior.apply();
});

The found: function is applied to all found nodes. The onclick: identifier will bind an onclick function to all found nodes. You can use any Dom Event name, such as onclick, onmouseenter, onmouseleave, onblur, etc.

Behaviors with topics

Using Dojo's native topic system, you can pass a named channel, and any node found during the apply() period will publish on that channel:

require(["dojo/behavior", "dojo/topic"], function(behavior, topic){
    behavior.add({
        "#someUl > li": "/found/li"
    });
    topic.subscribe("/found/li", function(msg){
        console.log('message: ', msg);
    });
    behavior.apply();
});