| Before we describe how the image map works, let's summarize the basic steps for creating custom components. You can apply the following steps while developing your own custom component. 1. | Create a custom component class that does the following: - a. Overrides the getFamily method to return the component family, which is used to look up renderers that can render the component.
- b. Includes the rendering code or delegates it to a renderer (explained in step 2).
- c. Enables component attributes to accept expressions.
- d. Queues an event on the component if the component generates events.
- e. Saves and restores the component state.
| 2. | Delegate rendering to a renderer if your component does not handle the rendering. To do this: - a. Create a custom renderer class by extending javax.faces.render.Renderer.
- b. Register the renderer to a render kit.
- c. Identify the renderer type in the component tag handler.
| 3. | Register the component. | 4. | Create an event handler if your component generates events. | 5. | Write a tag handler class that extends javax.faces.webapp.UIComponentELTag. In this class, you need a getrendererType method, which returns the type of your custom renderer if you are using one (explained in step 2); a getComponentType method, which returns the type of the custom component; and a setProperties method, with which you set all the new attributes of your component. | 6. | Create a tag library descriptor (TLD) that defines the custom tag. |
The application architect does the work of registering the custom component and the renderer. See Registering a Custom Converter (page 473) and Registering a Custom Renderer with a Render Kit (page 478) for more information. Using a Custom Component (page 386) discusses how to use the custom component in a JavaServer Faces page. |