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Document ID: 1390 Branch: main Language: default Name: Expression Languages Document Type: Cocoon Document Created: 6/7/07 6:04:16 PM Creator (owner): Reinhard Pötz State: publish Parts ===== Content ------- Mime type: text/xml Size: 4195 bytes Content: <html> <body> <p>The JXTemplate Generator supports two embedded expression languages: <a href="http://jakarta.apache.org/commons/jexl";>Jexl</a> and <a href="http://jakarta.apache.org/commons/jxpath";>JXPath</a>. Apache <a href="http://jakarta.apache.org/commons/jexl";>Jexl</a> provides an extended version of the expression language of the <a href="http://java.sun.com/webservices/docs/1.0/tutorial/doc/JSTL.html";>JSTL</a>. Apache <a href="http://jakarta.apache.org/commons/jxpath";>JXPath</a> provides an interpreter of the <a href="http://www.w3.org/TR/xpath";>XPath</a> expression language that can apply XPath expressions to graphs of Java objects of all kinds: JavaBeans, Maps, Servlet contexts, DOM etc, including mixtures thereof. </p> <p>Having an embedded expression language allows a page author to access an object using a simple syntax such as</p> <pre><site signOn="${accountForm.signOn}"> </pre> <p>Embedded Jexl expressions are contained in <tt>${}</tt>.</p> <p>Embedded JXPath expressions are contained in <tt>#{}</tt>.</p> <p>The referenced objects may be Java Beans, DOM, or JavaScript objects from a Flowscript. In addition, a special <tt>cocoon</tt> object providing access to the Cocoon <a href="daisy:518#FOM">FOM</a> is available as both a JXPath and Jexl variable in a template.</p> <p>The <tt>cocoon</tt> object contains the following properties:</p> <ul> <li><a href="daisy:518#request">request</a>: <br/> The current Cocoon request</li> <li><a href="daisy:518#session">session</a>: <br/> The user session associated with the current request</li> <li><a href="daisy:518#context">context</a>: <br/> The Cocoon context associated with the current request</li> <li><tt>parameters</tt>: <br/> A map containing the parameters passed to the generator in the pipeline</li> <li><a href="daisy:518#WebContinuation">continuation</a>: <br/> The current Web Continuation from your Flowscript</li> </ul> <p>Jexl Example:</p> <pre>The content type of the current request is ${cocoon.request.contentType} </pre> <p>JXPath Example:</p> <pre>The content type of the current request is #{$cocoon/request/contentType} </pre> <p>You would typically access the <tt>id</tt> of the Web Continuation:</p> <pre><form action="${cocoon.continuation.id}"> </pre> <p>You can also reach previous continuations via its <tt>parent</tt> property: </p> <pre><form action="${cocoon.continuation.parent.id}" > </pre> <p>or using an XPath expression:</p> <pre><form action="#{$cocoon/continuation/parent/id}" > </pre> <p>Deprecated Variables:</p> <p>The following variables are deprecated but still supported:</p> <ul> <li> <a href="file:/home/daisy/tmpdocimport/documentation/apidocs/org/apache/cocoon/environment/Request.html">org.apache.cocoon.environment.Request</a> <tt>request</tt>: <br/> The current Cocoon request (deprecated: use <tt>cocoon.request</tt> instead) </li> <li> <a href="file:/home/daisy/tmpdocimport/documentation/apidocs/org/apache/cocoon/environment/Session.html">org.apache.cocoon.environment.Session</a> <tt>session</tt>: <br/> The current user session (deprecated: use <tt>cocoon.session</tt> instead)</li> <li> <a href="file:/home/daisy/tmpdocimport/documentation/apidocs/org/apache/cocoon/environment/Context.html">org.apache.cocoon.environment.Context</a> <tt>context</tt>: <br/> The current context (deprecated: use <tt>cocoon.context</tt> instead)</li> <li> <a href="file:/home/daisy/tmpdocimport/documentation/apidocs/org/apache/cocoon/components/flow/WebContinuation.html">org.apache.cocoon.components.flow.WebContinuation</a> <tt>continuation</tt>: <br/> The current Web Continuation (deprecated: use <tt>cocoon.continuation</tt> instead)</li> </ul> <p class="note">When used inside flow, JXTemplate has access to Java and can therefore evaluate expressions like "java.util.Date()" or "java.util.HashMap()". This does <strong>NOT</strong> work when JXTemplates are used without flow. Some symptoms:<br/> [*<jx:out value="${java.util.Date()"/>*] results in [**]</p> <p class="note"><jx:formatDate value="${java.util.Date()}" pattern="yyyyMMdd"/> results in 'Cannot format given Object as a Date'</p> </body> </html> Collections =========== The document belongs to the following collections: cdocs-template
