Configuring JSP Templates for an Asset Renderer

An asset can be displayed in several different ways in the Asset Publisher. There are three templates to implement provided by the AssetRenderer interface:

• abstract
• full_content
• preview

Besides these supported templates, you can also create JSPs for buttons you’d like to provide for direct access and manipulation of the asset. For example,

• Edit
• View
• View in Context

The BlogsEntryAssetRenderer customizes the AssetRenderer’s provided JSP templates and adds a few other features using JSPs. You’ll inspect how the blogs asset renderer is put together to satisfy JSP template development requirements.

1. Add the getJspPath(...) method to your asset renderer. This method should return the path to your JSP, which is rendered inside the Asset Publisher. This is how the BlogsEntryAssetRenderer uses this method:

   @Override
   public String getJspPath(HttpServletRequest request, String template) {
       if (template.equals(TEMPLATE_ABSTRACT) ||
           template.equals(TEMPLATE_FULL_CONTENT)) {
   
           return "/blogs/asset/" + template + ".jsp";
       }
       else {
           return null;
       }
   }
   

   Blogs assets provide abstract.jsp and full_content.jsp templates. This means that a blogs asset can render a blog’s abstract description or the blog’s full content in the Asset Publisher. Those templates are located in the com.liferay.blogs.web module’s src/main/resources/META-INF/resources/blogs/asset folder. You could create a similar folder for your JSP templates used for this method. The other template provided by the AssetRenderer interface, preview.jsp, is not customized by the blogs asset renderer, so its default template is implemented.

   You must create a link to display the full content of the asset. You’ll do this later.

2. Now that you’ve added the path to your JSP, you must include that JSP. Since the BlogsEntryAssetRenderer class extends the BaseJSPAssetRenderer, it already has an include(...) method to render a specific JSP. You must override this method to set an attribute in the request to use in the blog’s views:

   @Override
   public boolean include(
           HttpServletRequest request, HttpServletResponse response,
           String template)
       throws Exception {
   
       request.setAttribute(WebKeys.BLOGS_ENTRY, _entry);
   
       return super.include(request, response, template);
   }
   

   The attribute includes the blogs entry object. Adding the blog object this way is not mandatory; you could obtain the blog entry directly from the view. Using the include(...) method, however, follows the best practice for MVC portlets.

   

   Figure 1: The abstract and full content views are rendererd differently for blogs.

Terrific! You’ve learned how to apply JSPs supported by the Asset Publisher for your asset. That’s not all you can do with JSP templates, however! The asset renderer framework provides several other methods that let you render convenient buttons for your asset.

1. Blogs assets provide an Edit button that lets you edit the asset. Provide this by adding the following method to the BlogsEntryAssetRenderer class:

   @Override
   public PortletURL getURLEdit(
           LiferayPortletRequest liferayPortletRequest,
           LiferayPortletResponse liferayPortletResponse)
       throws Exception {
   
       Group group = GroupLocalServiceUtil.fetchGroup(_entry.getGroupId());
   
       PortletURL portletURL = PortalUtil.getControlPanelPortletURL(
           liferayPortletRequest, group, BlogsPortletKeys.BLOGS, 0, 0,
           PortletRequest.RENDER_PHASE);
   
       portletURL.setParameter("mvcRenderCommandName", "/blogs/edit_entry");
       portletURL.setParameter("entryId", String.valueOf(_entry.getEntryId()));
   
       return portletURL;
   }
   

   The Asset Publisher loads the blogs asset using the Blogs application. Then the edit_entry.jsp template generates the HTML for an editing UI. Once the necessary edits are made to the asset, it can be saved from the Asset Publisher. Pretty cool, right?

2. You can specify how to view your asset by providing methods similar to the methods outlined below in the BlogsEntryAssetRenderer class:

   @Override
   public String getURLView(
           LiferayPortletResponse liferayPortletResponse,
           WindowState windowState)
       throws Exception {
   
       AssetRendererFactory<BlogsEntry> assetRendererFactory =
           getAssetRendererFactory();
   
       PortletURL portletURL = assetRendererFactory.getURLView(
           liferayPortletResponse, windowState);
   
       portletURL.setParameter("mvcRenderCommandName", "/blogs/view_entry");
       portletURL.setParameter("entryId", String.valueOf(_entry.getEntryId()));
       portletURL.setWindowState(windowState);
   
       return portletURL.toString();
   }
   
   @Override
   public String getURLViewInContext(
       LiferayPortletRequest liferayPortletRequest,
       LiferayPortletResponse liferayPortletResponse,
       String noSuchEntryRedirect) {
   
       return getURLViewInContext(
           liferayPortletRequest, noSuchEntryRedirect, "/blogs/find_entry",
           "entryId", _entry.getEntryId());
   }
   

   The getURLView(...) method generates a URL that displays the full content of the asset in the Asset Publisher. This is assigned to the clickable asset name. The getURLViewInContext(...) method provides a similar URL assigned to the asset name, but the URL redirects to the original context of the asset (e.g., viewing a blogs asset in the Blogs application). Deciding which view to render is configurable by navigating to the Asset Publisher’s Options → Configuration → Setup → Display Settings section and choosing between Show Full Content and View in Context for the Asset Link Behavior drop-down menu.

The Blogs application provides abstract and full_content JSP templates that override the ones provided by the AssetRenderer interface. The third template, preview, could also be customized. You can view the default preview.jsp template rendered in the Add → Content menu.

Figure 2: The `preview` template displays a preview of the asset in the Content section of the Add menu.

You’ve learned all about implementing the AssetRenderer’s provided templates and customizing them to fit your needs. Next, you’ll put your asset renderer into action by creating a factory.