Accessibility

Table of Contents

  1. Introduction
  2. Sample 1: Accessing data using HTTPService
  3. Sample 2: Accessing data using web services
  4. Sample 3: Accessing data using Remoting
  5. Sample 4: Flex programming model 101
  6. Sample 5: Updating data
  7. Sample 6: Publish/Subscribe messaging – the data push use case
  8. Sample 7: Publish/Subscribe messaging – the collaboration use case

BlazeDS 30-minute test drive

Sample 2: Accessing data using web services

Run the sample:

  1. Run the web services sample by opening the following URL in your browser: http://localhost:8400/samples/testdrive-webservice/index.html.

    Note: Since this application accesses a live web service, you must have an Internet connection to run it.

  2. Click "Get Data". The DataGrid is populated with data returned by the ProductWS web service hosted on livecycledata.org.

Code walkthrough:

Open main.mxml in the testdrive-webservice/src directory to examine the source code of the application.

You can also view the WSDL file for the web service used in this example at http://livecycledata.org/services/ProductWS?wsdl.

Using the WebService tag, you can invoke SOAP-based web services deployed in your application server or anywhere on the Internet. Objects returned by a web service are automatically deserialized into ActionScript objects. Similarly ActionScript objects passed as arguments to a web service operation are serialized according the WSDL description.

Notice that this example also added DataGrid column definitions (using DataGridColumn).

The BlazeDS server is not required to use the WebService. By default, the application tries to connect directly to the domain specified in the WebService wsdl attribute. This will work if one of the two conditions below is satisfied:

  1. The domain specified in the WebService wsdl attribute is the domain from which your application was downloaded.
  2. A crossdomain.xml file granting access to your application's originating domain is available on the domain specified in the WebService wsdl attribute. More information on crossdomain.xml is available here.

If you want your application to access services available on another domain without deploying a crossdomain.xml file on that domain (for example, because you may not own the target domain), you can set the useProxy attribute of the WebService to true as in this example. In this case, the request is sent to the BlazeDS proxy, which makes the request to the target domain on the client application's behalf. This configuration also provides more control over the access to the service. For example, you may configure the proxy to require authentication before accessing a service, log access to the service, and so on.

When using the proxy, you can specify a logical name in the WebService destination attribute instead of specifying a hardcoded value in the wsdl attribute. You then map this logical name to an actual URL in the WEB-INF\flex\proxy-config.xml file. Open this file to see how the ws-catalog destination is configured.

Flex supports both RPC-encoded and document-literal web services. Like HTTPService, WebService calls are asynchronous; you can set up result and fault event handlers.

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