O Guia Definitivo do Yii 1.1

Web Service
Web service is a software system designed to support interoperable machine-to-machine
interaction over a network. In the context of Web applications, it usually refers to a set of
APIs that can be accessed over the Internet and executed on a remote system hosting the
requested service. For example, a Flex-based client may invoke a function implemented
on the server side running a PHP-based Web application. Web service relies on SOAP as
its foundation layer of the communication protocol stack.
Yii provides CWebService and CWebServiceAction to simplify the work of implementing
Web service in a Web application. The APIs are grouped into classes, called service
providers. Yii will generate for each class a WSDL specification which describes what APIs
are available and how they should be invoked by client. When an API is invoked by a
client, Yii will instantiate the corresponding service provider and call the requested API to
fulfill the request.
Note: CWebService relies on the PHP SOAP extension. Make sure you have enabled
it before trying the examples displayed in this section.
Defining Service Provider
As we mentioned above, a service provider is a class defining the methods that can be
remotely invoked. Yii relies on doc comment and class reflection to identify which methods
can be remotely invoked and what are their parameters and return value.
Let's start with a simple stock quoting service. This service allows a client to request for
the quote of the specified stock. We define the service provider as follows. Note that we
define the provider classStockController by extending CController. This is not required. We
will explain why we do so shortly.
class StockController extends CController
{
/**
* @param string the symbol of the stock
* @return float the stock price
* @soap
*/
public function getPrice($symbol)
{
$prices=array('IBM'=>100, 'GOOGLE'=>350);
return isset($prices[$symbol])?$prices[$symbol]:0;
//...return stock price for $symbol
}
}