|
This guide reviews WebORB client code generation capabilities and provides
instructions for creating a Flex application using the generated code. At the
end of the walkthrough you will have a Flex client application loading data from
the server via a RemoteObject invocation.
To get started review the Java class below. The class is included into WebORB
distribution and provided here for the reference and to establish the context:
package weborb.examples;
import java.sql.*;
import weborb.util.log.*;
public class DataBinding
{
private static Connection connection;
public ResultSet getCustomers()
{
openConnection();
String query = "SELECT CustomerID, CompanyName, ContactName,
ContactTitle , Address , City , PostalCode ,
Country FROM Customers order by CustomerID;";
Statement statement = connection.createStatement();
ResultSet result = statement.executeQuery( query );
return result;
}
public void openConnection() throws Exception
{
if( connection != null )
return;
Class.forName( "org.hsqldb.jdbcDriver" );
connection = DriverManager.getConnection( "jdbc:hsqldb:.",
"sa","");
}
}
You can see and inspect the class in the service browser which is a part of the
WebORB management console. Start WebORB from the command line as shown below or
follow the directions for deploying WebORB into a Java servlet container:run from the weborb installation directory:
java -jar weborb.jar For the standalone mode the console is available at
http://localhost:8080, however when WebORB
is hosted in a Java EE server or servlet container, the console URL will also
include the context path for the WebORB web application.Open the Management
tab and navigate to the following path:
weborb.jar > weborb > examples > DataBinding
 Create a Flex Builder project for your
Flex application as described in the
'Creating a Flex
Application' section of the getting started with Flex and Java article.
Click the Download Code button to get a zip file with the generated code.
Expand the contents of the zip file into the created Flex Builder project. If
you are using Flex Builder 3, make sure to expand the code into the /src folder
in the project structure. The image below demonstrates the project structure in
Flex Builder 3 after the generated code has been added to the project:
Open the MXML Application file and add the following code:
<mx:Script>
<![CDATA[
import weborb.examples.DataBindingModel;
import weborb.examples.DataBinding;
[Bindable]
private var model:DataBindingModel;
private var dataBindingService:DataBinding;
private function init():void
{
// create the model object
model = new DataBindingModel();
// create the service proxy - responsible for carrying out
// remote method invocations and updating the model
dataBindingService = new DataBinding( model );
// invoke remote method
dataBindingService.getCustomers();
}
]]>
</mx:Script>
Modify the root mx:Application
element to invoke the init() method shown above on the
creationComplete event:
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute"
creationComplete="init()">
Switch to the Design view and add a data grid component to the created MXML
application. Switch back to the Source view and modify the data grid MXML as
shown below:
<mx:DataGrid x="10" y="37" width="467" height="143"
dataProvider="{model.getCustomersResult}">
</mx:DataGrid>
Notice the columns declaration is removed. Also, there is a data binding
between the grid's dataProvider property and a property in the model object. The
property in the model is automatically updated within the generated code when a
response from the remote service is available.
Save the file and run the application. When the application is loaded, it
makes a remote object invocation which runs a query. The query results are
displayed in the data grid. |
