I'm building a webpage that is composed of several controls, and trying to come up with an effective somewhat generic
client side sibling
control communication model. One of
the controls is
the menu
control. Whenever an item is clicked in here I wanted to expose a custom
client side event that other controls can subscribe to, so that I can achieve a loosely coupled sibling
control communication model.
To that end I've created a simple Javascript event collection class (code below) that acts as like a hub for
control event registration and event subscription. This code certainly gets
the job done, but my question is is there a better more elegant way to do this in terms of best practices or tools, or is this just a fools errand?
/// Event collection object - acts as
the hub for
control communication.
function ClientEventCollection()
{
this.ClientEvents = {};
this.RegisterEvent = _RegisterEvent;
this.AttachToEvent = _AttachToEvent;
this.FireEvent = _FireEvent;
function _RegisterEvent(eventKey)
{
if (!this.ClientEvents[eventKey])
this.ClientEvents[eventKey] = [];
}
function _AttachToEvent(eventKey, handlerFunc)
{
if (this.ClientEvents[eventKey])
this.ClientEvents[eventKey][this.ClientEvents[eventKey].length] = handlerFunc;
}
function _FireEvent(eventKey, triggerId, contextData )
{
if (this.ClientEvents[eventKey])
{
for (var i = 0; i < this.ClientEvents[eventKey].length; i++)
{
var fn = this.ClientEvents[eventKey][i];
if (fn)
fn(triggerId, contextData);
}
}
}
}
// load new collection instance.
var myClientEvents = new bsdClientEventCollection();
// register
events specific to
the control that owns it, this will be emitted by each respective
control.
myClientEvents.RegisterEvent("menu-item-clicked");
Here is
the part where this code above is consumed by source and subscriber controls.
// menu
control
$(document).ready(function()
{
$(".menu > a").click( function(event)
{
//event.preventDefault();
myClientEvents.FireEvent("menu-item-clicked", $(this).attr("id"), null);
});
});
<div style="float: left;" class="menu">
<a id="1" href="#">Menu Item1</a><br />
<a id="2" href="#">Menu Item2</a><br />
<a id="3" href="#">Menu Item3</a><br />
<a id="4" href="#">Menu Item4</a><br />
</div>
// event subscriber
control
$(document).ready(function()
{
myClientEvents.AttachToEvent("menu-item-clicked", menuItemChanged);
myClientEvents.AttachToEvent("menu-item-clicked", menuItemChanged2);
myClientEvents.AttachToEvent("menu-item-clicked", menuItemChanged3);
});
function menuItemChanged(id, contextData)
{
alert('menuItemChanged ' + id);
}
function menuItemChanged2(id, contextData)
{
alert('menuItemChanged2 ' + id);
}
function menuItemChanged3(id, contextData)
{
alert('menuItemChanged3 ' + id);
}
