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| There is a tag library available that makes information about the Snaps environment available to the host from within a |
| JSP page. The prefix and URI to declare are <code class="code"><%@ taglib prefix="snaps" uri="http://www.eclipse.org/virgo/snaps" |
| %></code>. You can now access an array of all the Snaps currently registered with the host. Each snap in the array |
| has two values, the first is the context path the Snap is registered with, as given in the snaps manifest header. The |
| second is an array of properties, if any, given in a property file in the snap. The file must be in the <code class="literal">META-INF |
| </code> directory and have a name of <code class="literal">snap.properties</code>. The following code snippet shows all of these |
| in use to produce links to each of the installed snaps. |
| </p><pre class="programlisting"> |
| <snaps:snaps var="snaps"> |
| <c:forEach var="snap" items="${snaps}"> |
| <a href="<c:url value="${snap.contextPath}${snap.properties['link.path']}"/>"> |
| ${snap.properties['link.text']}</a> |
| </c:forEach> |
| </snaps:snaps> |
| </pre><p> |
| The first line uses the Snaps tag library to place the array of snaps into the <code class="code">snaps</code> variable. Then a |
| <code class="code">forEach</code> loop goes through each snap. The content of the <code class="code">forEach</code> loop is the really interesting |
| bit. The first variable <code class="code">${snap.contextPath}</code> returns the context path of the snap. The two lookups are for |
| properties <code class="code">${snap.properties['something']}</code>. They rely on the snap having the properties file in place with |
| <code class="literal">link.path</code> and <code class="literal">link.text</code> defined in it. This shows the flexibility you have for defining |
| your own contract between the host and its snaps. In this case each snap can contribute extra information about how links in |
| a menu should be constructed. |
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