1.3.2. How it works

The first time we navigate to messages.jsp, the page will try to resolve the messageList context variable. Since this variable is not yet initialized, Seam calls the factory method findMessages, which queries the database and retrieves a DataModel. This provides the row data required to render the <h:dataTable>.

When the user clicks the <h:commandLink>, JSF calls the select() action listener. Seam intercepts this call and injects the selected row data into the message attribute of the messageManager component. The action listener fires, marking the selected Message as read. At the end of the call, Seam outjects the selected Message to the message context variable. Next, the EJB container commits the transaction, and the change to the Message is flushed to the database. Finally, the page is re-rendered, redisplaying the message list, and displaying the selected message below it.

When the user clicks the <h:commandButton>, JSF calls the delete() action listener. Seam intercepts this call and injects the selected row data into the message attribute of the messageList component. The action listener fires, which removes the selected Message from the list, and also calls remove() on the EntityManager. At the end of the call, Seam refreshes the messageList context variable and clears the message context variable. The EJB container commits the transaction, and deletes the Message from the database. Finally, the page is re-rendered, redisplaying the message list.