CoProc2 is a DataPower developer utility used to execute XSLT stylesheets on a remote DataPower appliance. Most IDEs support running XSLT locally. But few IDEs provide an XSLT runtime environment that supports the DataPower extension APIs that are pervasive in most DataPower stylesheets. CoProc2 submits a developer's stylesheet, together with any XML input or HTTP headers, to a MPGW service proxy running on the DataPower appliance. The service proxy executes the stylesheet against any input. The results are returned in the response.

The CoProc2 Eclipse Plugin wraps the CoProc2 Java class inspired by Hermann's BLOG Post. The wrapper takes the form of an Eclipse Run Configuration, which is the mechanism we use in Eclipse to run other Java-based actions such as run a stand-alone Java program, an application test environment, an applet, or a JUnit test. In this case, the configuration panel is oriented to running CoProc2.

In order to use the latest version of the CoProc2 plug-in, you have to use the MPGW that corresponds to it. You can download this along with an CoProc2 Installation Guide from Paul Glezen's Homepage. Detailed documentation is included with the plugin.

There are two components to install:

• the MPGW service on the DataPower appliance
• the Eclipse plugin into the Eclipse workspace

It's important that the two components are compatible.

The service export can be obtained from

http://glezen.org/update/coproc2-2/CoProc22.zip

Designate an application domain in your target DataPower appliance for running the coproc22 MPGW. The target appliance should be one used for development purposes, not production. A typical practice is to create an application domain named Utilities and import the CoProc22.zip there.

Once the service proxy is imported, edit the HTTP FSH named coproc22. Change the Local IP Address and Port Number to something suitable for your environment.

It's recommended that you not listen on 0.0.0.0 like the example above; instead it's safer to choose a particular interface allocated to development traffic. The port number may be any port you like. You may verify the installation with the cURL command as in the following example.

$ curl http://192.168.152.12:2224/coproc/version
Version: 2.0.0
Date: May 21, 2011

Currently the plugin requires Eclipse 3.6 or later. Since the point of the plugin is to assist with XSLT development, it's best to have the Web Tools Platform (WTP) installed since this provides the Eclipse XSLT support. Start Eclipse and follow these steps to install the CoProc2 plugin.

1. Select Help → Install New Software ....

2. Click the Add button next to the Work with field. This displays the Add Repository dialog.

3. Enter CoProc2 for the Name field. For Location, enter http://glezen.org/update/coproc202.

4. Click OK so that the CoProc2-2 update site is chosen. Select the CoProc2 plugin as shown below.

   

5. Click Next.

6. Continue clicking Next through the information panels and license acceptance.

7. Click Finish at the end. Since this plugin is not signed with a digital signature, you can expect to see a security warning about unsigned content. Click OK.

8. Restart Eclipse after the plugin installation in complete.

This completes the plugin installation. As a verification, you can select Help → About Eclipse. You should see an entry for the CoProc2 as shown in the figure below.

CoProc2 is a DataPower service together with an Eclipse plugin. The plugin submits a stylesheet together with its input to the CoProc2 service for processing and displays the results to the Eclipse console. In the following example, the stylesheet report.xsl processes the XML file report.xml.

1. Open the Run Configurations view as shown below.

   

2. Right-click the CoProc2 type and select New.

   

3. Name the configuration Report.

4. Click Test Connection to ensure we can each CoProc2 service on the DataPower appliance.

5. Enter the stylesheet information through the Browse button.

6. Uncheck Set Input Context to NULL since we have input.

7. Enter the input XML file through the Browse button.

8. Click Apply.

9. Click Run.

   

The console window contains the output from the transform. Running the configuration creates a Run short-cut that may be used for subsequent runs. First click the tiny black down-arrow next to the green run icon, then select Report from the list. The run configuration dialog isn't needed again unless the input or headers need to be changed.

The plugin configuration steps are documented in the Eclipse help section.

HTTP proxy support has not yet been incorporated into the remote execution of the stylesheet. If you are working at a location that requires an outbound proxy configuration, the remote execution will fail. The Test Connection button will succeed because it inherits the proxy configuration of the Eclipse workbench (which is configured through the Eclipse preferences under General → Network Connections. However the remote invocation of the stylesheet spawns a separate JVM that does not inherit the settings.

If a stylesheet causes an HTTP 500 returned, the only indication is the Eclipse console output is an ugly message like the following.

In this example, the stylesheet's <reject/> tag executed, aborting the rule (which was actually the desired behavior). Be sure to follow up your remote stylesheet execution by checking the DataPower logs of the application domain in which the CoProc2 service is deployed.