Compare Sitemesh - Tiles - SiteMesh

Tiles and Sitmesh are both page decoration tools, but they go about things very differently.

From my (limited) understanding, Tiles you have to 'push' everything into it. If you want a title - you need to specify it in tiles-def.xml. I'm not sure what Tiles gives you that you couldn't achieve with a big velocity template & a properties file to pull the value in from.

Sitemesh on the other hand, understands the HTML of the page you are decorating. So you just have to produce HTML as your raw input. You can view your pages with or without decorators, and they are still valid HTML files.

However, the distinction is that you can only have one decorator per page, rather than lots of 'tiles'. Mostly this fits with web design, as usually there is one rather large 'content' area, with some other navigation around it.

The other advantage is that your pages are almost completely decoupled from your decorators. These three URLs are exactly the same, aside from the decorators used:

If you want to do what you are after - you can achieve it with sitemesh. You can do your conditional 'put admin navigation on the admin page' either with different decorators, or with conditional logic inside a decorator.

You could even use Tiles inside your decorator (decorators as just JSP files) to do this logic.

The other advantage of sitemesh is that you can use it to decorate 'parts of pages'.

The code for this page looks like:

http://jira.opensymphony.com/secure/CreateIssue!default.jspa

<html>
<head>
    <title>Create Issue</title>
</head>

<body>
<page:applyDecorator name="jiraform">
  <page:param name="title">Create Issue</page:param>
  <page:param name="description"><b>Step 1 of 2</b>:
        Choose the project and issue type...</page:param>
  <page:param name="action">CreateIssue.jspa</page:param>
  <page:param name="submitName">Next &gt;&gt;</page:param>

  <ui:select label="'Project'" name="'pid'"
       list="allowedProjects" listKey="'long('id')'"
       listValue="'string('name')'" />
  <ui:select label="'Issue Type'" name="'issueType'"
       list="/constantsManager/issueTypes" listKey="'string('id')'"
       listValue="'string('name')'">
    <ui:param name="'helpURL'">issues</ui:param>
        <ui:param name="'helpURLFragment'">#IssueTypes</ui:param>
  </ui:select>
</page:applyDecorator>
</body>
</html>

That's it - the whole page. The 'jiraform' decorator decorates the form box, and the normal decorator decorates the whole page. Take a look at the source for the above to see how much extra is added.