public void service()

in tapestry-framework/src/org/apache/tapestry/engine/ActionService.java [92:166]
50 lines of code
10 McCabe index (conditional complexity)

    public void service(
        IEngineServiceView engine,
        IRequestCycle cycle,
        ResponseOutputStream output)
        throws ServletException, IOException
    {
        IAction action = null;
        String componentPageName;
        int count = 0;

        String[] serviceContext = getServiceContext(cycle.getRequestContext());

        if (serviceContext != null)
            count = serviceContext.length;

        if (count != 4 && count != 5)
            throw new ApplicationRuntimeException(
                Tapestry.getMessage("ActionService.context-parameters"));

        boolean complex = count == 5;

        int i = 0;
        String stateful = serviceContext[i++];
        String pageName = serviceContext[i++];
        String targetActionId = serviceContext[i++];

        if (complex)
            componentPageName = serviceContext[i++];
        else
            componentPageName = pageName;

        String targetIdPath = serviceContext[i++];

        IPage page = cycle.getPage(pageName);

		// Setup the page for the rewind, then do the rewind.

		cycle.activate(page);
		
        IPage componentPage = cycle.getPage(componentPageName);
        IComponent component = componentPage.getNestedComponent(targetIdPath);

        try
        {
            action = (IAction) component;
        }
        catch (ClassCastException ex)
        {
            throw new ApplicationRuntimeException(
                Tapestry.format("ActionService.component-wrong-type", component.getExtendedId()),
                component,
                null,
                ex);
        }

        // Only perform the stateful check if the application was stateful
        // when the URL was rendered.

        if (stateful.equals(STATEFUL_ON) && action.getRequiresSession())
        {
            HttpSession session = cycle.getRequestContext().getSession();

            if (session == null || session.isNew())
                throw new StaleSessionException();
        }

        cycle.rewindPage(targetActionId, action);

        // During the rewind, a component may change the page.  This will take
        // effect during the second render, which renders the HTML response.

        // Render the response.

        engine.renderResponse(cycle, output);
    }