Zend Framework Dojo Integration

I'm pleased to announce that Zend Framework will be partnering with Dojo Toolkit to deliver out-of-the-box Ajax and rich user interfaces for sites developed in Zend Framework.

First off, for those ZF users who are using other Javascript toolkits: Zend Framework will continue to be basically JS toolkit agnostic. You will still be able to use whatever toolkit you want with ZF applications. ZF will simply be shipping Dojo so that users have a toolkit by default. Several points of integration have been defined, and my hope is that these can be used as a blueprint for community contributions relating to other javascript frameworks. In the meantime, developers choosing to use Dojo will have a rich set of components and integration points to work with.

The integration points we have defined for our initial release are as follows:

  • JSON-RPC Server: We are re-working the Zend_Json_Server that has been in our incubator since, oh, what? 0.2.0? and never released to actually follow a specification: JSON-RPC. This will allow it to work seamlessly with Dojo, as well as other toolkits that have JSON-RPC client implementations. I have actually completed work on this, though the proposal is waiting to be approved; if you want to check it out, you can find it in the ZF svn.

    The original Zend_Json_Server implementation will be abandoned. It was never fully tested nor fully documented, which has prevented its release. Additionally, since it implemented its own ad-hoc standard, it did not provide the type of interoperability that a true JSON-RPC server implementation will provide. I am excited that we will finally be able to provide a standards-compliant solution for general availability.

    One final note: there are currently two different JSON-RPC specifications, 1.0 and 2.0. Currently, the implementation I've been working on will switch payload formats based on the request, and can deliver different SMD formats appropriately as well.

  • dojo() View Helper: Enabling Dojo for a page is not typically as trivial as just loading the dojo.js script -- you have a choice of loading it from the AOL CDN or a local path, and also may want or need to load additional dojo, dijit, or dojox modules, specify custom modules and paths, specify code to run at onLoad(), and specify stylesheets for decorating dijits. On top of this, this information may change from page to page, and may only be needed for a subset of pages. The dojo() view helper will act as a placeholder implementation, and facilitate all of the above tasks, as well as take care of rendering the necessary style and script elements in your page.
  • Form Element implementations: One area that developers really leverage javascript and ajax toolkits is forms. In particular, many types of form input can benefit from advanced and rich user interfaces that only javascript can provide: calendar choosers, time selectors, etc. Additionally, many like to use client-side validation in order to provide instantaneous validation feedback to users (instead of requiring a round-trip to the server). We will be identifying a small group of form elements that we feel solve the most relevant use cases, and write Dojo-specific versions that can be utilized with Zend_Form. (One thing to note: Zend_Form's design already works very well with Dojo, allowing many widgets and client-side validations to be created by simply setting the appropriate element attributes.)
  • dojo.data Compatibility: dojo.data defines a standard storage interface; services providing data in this format can then be consumed by a variety of Dojo facilities to provide highly flexible and dynamic content for your user interfaces. We will be building a component that will create dojo.data compatible payloads with which to respond to XmlHttpRequests; you will simply need to pass in the data, and provide metadata regarding it.

So, some examples are in order. First off, Zend_Json_Server operates like all of ZF's server components: if follows the SoapServer API. This allows you to attach arbitrary classes and functions to the server component. Additionally, it can build a Service Mapping Description (SMD) that Dojo can consume in order to discover valid methods and signatures. As an example, on the server side you could have the following:


// /json-rpc.php
// Assumes you have a class 'Foo' with methods 'bar' and 'baz':
$server = new Zend_Json_Server();
$server->setClass('Foo')
       ->setTarget('/json-rpc.php')
       ->setEnvelope('JSON-RPC-1.0')
       ->setDojoCompatible(true);

// For GET requests, simply return the service map
if ('GET' == $_SERVER['REQUEST_METHOD']) {
    $smd = $server->getServiceMap();
    header('Content-Type: application/json');
    echo $smd;
    exit;
}

$server->handle();

On your view script side, you might then do the following:


<h2>Dojo JSON-RPC Demo</h2>
<input name=\"foo\" type=\"button\" value=\"Demo\" onClick=\"demoRpc()\"/>
<? 
$this->dojo()->setLocalPath('/js/dojo/dojo.js')
             ->addStyleSheetModule('dijit.themes.tundra')
             ->requireModule('dojo.rpc.JsonService');
$this->headScript()->captureStart(); ?>
function demoRpc()
{
    var myObject = new dojo.rpc.JsonService('/json-rpc.php');
    console.log(myObject.bar());
}
<? $this->headScript()->captureEnd() ?>

And, finally, in your layout script, you might have the following:


<?= $this->doctype() ?>
<html>
    <head>
        <title>...</title>
        <?= $this->dojo() ?>
        <?= $this->headScript() ?>
    </head>
    <body class=\"tundra\">
        <?= $this->layout()->content ?>
    </body>
</html>

The example doesn't do much -- it simply logs the results of the JSON-RPC call to the console -- but it demonstrates a number of things:

  • dojo() View Helper: The example shows using dojo from a local path relative to the server's document root; using the 'Tundra' stylesheet shipped with Dojo and attaching it to the layout; capturing a required module ('dojo.rpc.JsonService'); and rendering the necessary Dojo stylsheet and script includes in the layout.
  • JSON-RPC client: Dojo requires that you point the JsonService to an endpoint that delivers a Service Mapping Description; in this example, I use any GET request to return the SMD. Once the SMD is retrieved, any methods exposed are available to the Javascript object as if they were internal methods -- hence myObject.bar(). Dojo's current implementation performs all other requests as POST requests, passing the data via the raw POST body.

There will be more to come in the future, and I will be blogging about developments as I get more proposals up and code into the repository. All in all, this is a very exciting collaboration, and should help provide ZF developers the ability to rapidly create web applications with rich, dynamic user interfaces.

Update: Andi has posted an FAQ on our integration.

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