Handler Sample

The idea of this sample is to demonstrate how to use media type handlers. The sample application is to process project proposals, so we'll be using a component that intercepts Registry put() requests with a particular proposal media-type. The Handler will read the proposal and mark it as valid or not. In order to be a valid proposal there should be a number of fields - if all of them are there then the handler will mark the proposal as valid. If one or more fields are missing then the proposal would be invalid.

Instructions

1. Copy the <G-REG_HOME>/samples/handler/bin/org.wso2.carbon.registry.samples.handler-4.6.0.jar file into the <G-REG_HOME>/repository/components/dropins/ directory.

2. You also can upload handlers through the administration console by visiting the "Add" in "Extensions."

3. Edit the registry.xml file which is in GREG_HOME/repository/conf folder and add the following XML snippet.

<handler class="org.wso2.carbon.registry.samples.handler.ProjectProposalMediaTypeHandler" methods="PUT">
    <filter class="org.wso2.carbon.registry.core.jdbc.handlers.filters.MediaTypeMatcher">
        <property name="mediaType">pp</property>
    </filter>
</handler>

4. You also can add the handler configuration through the administration console.

4.1. Enter the "Extensions" menu.

4.2. Open the "Handlers" configuration menu.

4.3. Click on "Add New Handler."

4.4. Add the handler configuration.

See also Configuring Handlers.

5. Start the server and go to admin console. See Running the Product for more information.

6. Browse the resources tree by visiting "Browse" menu in "Resources."

7. Add a new resource. See Adding a Resource.

8. Select the "Upload content from file" from the drop-down list.

9. Select your project proposal and type the media type as "pp." And click "Add."

10. You should see a confirmation like this:

11. Browse to the added project proposal. You could see the "Properties" and the "Tag" have been added to the resource.