By Hamish Friedlander, with thanks to "SilverStripe":http://www.silverstripe.com/
Concrete tries to provide a new model of code organisation - a replacement for Object Oriented programming that is focused on adding functions to groups of DOM elements based on the structure and contents of those DOM elements. It's a merging of the model and view layer that initially seems weird, but can give very powerful results.
We're standing on the shoulders of giants here - combining ideas from Prototype's behaviour & lowpro and jQuery's effen & livequery (who themselves stole ideals from Self's Morphic UI and others), but extending & combining the concepts presented in those tools to provide a complete alternative to traditional OO concepts - self-aware methods, inheritance, polymorphisim and namespacing without a single class definition.
h2. Getting Started
* Walk through the "Tutorial":http://hafriedlander.github.com/jquery.concrete/tutorial/
* Watch the "Screencast":http://www.vimeo.com/6353390 (shot during a introductory developer meeting at SilverStripe)
* Join the "Google Group":http://groups.google.com/group/jquery-concrete and let us know what you think, or what other features you'd like to see
<div>Background will turn blue when clicked on</div>
<div>Will also have blue background when clicked on</div>
<div class='green'>Will have green text when clicked on. Background color will not change</div>
</body>
</code></pre>
h2. Constructors / Destructors
Declaring a function with the name `onmatch` will create a behavior that is called on each object when it matches. Likewise, `onunmatch` will
be called when an object that did match this selector stops matching it (because it is removed, or because you've changed its properties).
Note that an onunmatch block must be paired with an onmatch block - an onunmatch without an onmatch _in the same concrete definition block_ is illegal
Like other functions, only the most specific definition will be used. However, because property changes are not atomic, this may not work as you
expect.
h2. Namespaces
To avoid name clashes, to allow multiple bindings to the same event, and to generally seperate a set of functions from other code you can use namespaces
Clicking on a div will change the background **and** foreground color.
This is particularly important when writing reusable code, since otherwise you can't know before hand whether your event handler will be called or not
Although a namespace can be any string, best practise is to name them with dotted-identifier notation.
h4. Namespaces and scope (or What the hell's up with that ugly function closure)
Inside a namespace definition, functions remember the namespace they are in, and calls to other functions will be looked up inside that namespace first.
Where they don't exist, they will be looked up in the base namespace
Then doing $('div').bar(); will _not_ display b. Even though the span rule could never match a div, because baz is defined for some rule in the foo namespace, the base namespace will never be checked
You can also nest declarations. In this next example, we're defining the functions $().concrete('zap').bar() and $().concrete('zap.pow').baz()
<pre><code>
$.concrete('zap', function($){
$('div').concrete({
bar: function() { .. }
})
$.concrete('pow', function($){
$('div').concrete({
baz: function() { .. }
})
})
})
</code></pre>
h4. Calling to another namespace (and forcing base)
Inside a namespace, namespace lookups are by default relative to the current namespace.
In some situations (such as the last example) you may want to force using the base namespace. In this case you can call concrete with the first argument being the base namespace code '.'. For example, if the first definition in the previous example was
Sometimes a block outside of a namespace will need to refer to that namespace repeatedly. By passing a function to the concrete function, you can change the looked-up namespace
This equivalent to /with/ in javascript, and just like /with/, care should be taken to only use this construct in situations that merit it.
h2. License
Copyright (C) 2009 Hamish Friedlander (hamish@silverstripe.com) and SilverStripe Limited (www.silverstripe.com). All rights reserved.
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
* Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
* Neither the name of Hamish Friedlander nor SilverStripe nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
