JSF does not define any kind of action listener that is triggered when a page is accessed via a non-faces request (for example, a HTTP GET request). This can occur if the user bookmarks the page, or if we navigate to the page via an <h:outputLink>.

Sometimes we want to begin a conversation immediately the page is accessed. Since there is no JSF action method, we can't solve the problem in the usual way, by annotating the action with @Begin.

A further problem arises if the page needs some state to be fetched into a context variable. We've already seen two ways to solve this problem. If that state is held in a Seam component, we can fetch the state in a @Create method. If not, we can define a @Factory method for the context variable.

If none of these options works for you, Seam lets you define a page action in the pages.xml file.

<pages>
    <page view-id="/messageList.jsp" action="#{messageManager.list}"/>
    ...
</pages>

This action method is called at the beginning of the render response phase, any time the page is about to be rendered. If a page action returns a non-null outcome, Seam will process any appropriate JSF and Seam navigation rules, possibly resulting in a completely different page being rendered.

If all you want to do before rendering the page is begin a conversation, you could use a built-in action method that does just that:

<pages>
    <page view-id="/messageList.jsp" action="#{conversation.begin}"/>
    ...
</pages>

Note that you can also call this built-in action from a JSF control, and, similarly, you can use #{conversation.end} to end conversations.

If you want more control, to join existing conversations or begin a nested conversion, to begin a pageflow or an atomic conversation, you should use the <begin-conversation> element.

<pages>
    <page view-id="/messageList.jsp">
       <begin-conversation nested="true" pageflow="AddItem"/>
    <page>
    ...
</pages>

There is also an <end-conversation> element.

<pages>
    <page view-id="/home.jsp">
       <end-conversation/>
    <page>
    ...
</pages>

To solve the first problem, we now have five options: