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Posted to dev@commons.apache.org by js...@apache.org on 2002/05/30 20:24:00 UTC
cvs commit: jakarta-commons-sandbox/jelly/xdocs todo.xml index.xml
jstrachan 02/05/30 11:24:00
Modified: jelly/xdocs todo.xml index.xml
Log:
Updated the documentation making a much more descriptive home page
Revision Changes Path
1.3 +1 -0 jakarta-commons-sandbox/jelly/xdocs/todo.xml
Index: todo.xml
===================================================================
RCS file: /home/cvs/jakarta-commons-sandbox/jelly/xdocs/todo.xml,v
retrieving revision 1.2
retrieving revision 1.3
diff -u -r1.2 -r1.3
--- todo.xml 30 May 2002 17:28:11 -0000 1.2
+++ todo.xml 30 May 2002 18:23:59 -0000 1.3
@@ -19,6 +19,7 @@
It'd be handy for recursive builds!</li>
<li>autogenerate tag library documentation, in a kinda javadoc style, showing all tag libraries,
their tags and descriptions of their tags</li>
+ <li>Develop a http tag library, probably based on commons-httpclient, that can be used for scripting web services</li>
<li>Patch TagLibrary to alias all <mixedCase> tags to <mixed-case> tags</li>
<li>Add tags <copy> <copyOf> <element> <attribute> to JSL </li>
<li>Add JSL test cases to test for ordering of patterns and that the correct output comes out.</li>
1.5 +99 -11 jakarta-commons-sandbox/jelly/xdocs/index.xml
Index: index.xml
===================================================================
RCS file: /home/cvs/jakarta-commons-sandbox/jelly/xdocs/index.xml,v
retrieving revision 1.4
retrieving revision 1.5
diff -u -r1.4 -r1.5
--- index.xml 24 May 2002 12:02:29 -0000 1.4
+++ index.xml 30 May 2002 18:23:59 -0000 1.5
@@ -11,32 +11,120 @@
<section name="Jelly : Java and XML based scripting engine">
-<p>
- <b>Jelly</b>
-</p>
-
-<p><em>Jelly</em> is an XML based scripting and processing engine. Jelly borrows many
-good ideas from both JSP custom tags, Velocity, Cocoon and the
+<p><em>Jelly</em> is a Java and XML based scripting and processing engine. Jelly borrows many
+good ideas from both JSP custom tags, Velocity, Cocoon, Ant and the
scripting engine inside XDoclet. Jelly can be used from the command line, inside
-Ant or inside a Servlet.
+Ant or inside a Servlet, Web Service, JMS MessageListener or embedded directly into your software.
</p>
<p>
Jelly is completely extendable via custom tags in a similar way to JSP.
Though Jelly is really simple and has no dependencies either Servlets or JSP.
+Jelly has native support for plugin expression languages and includes support
+for the JSP, JSTL and JSF expression language via
+
+<!-- #### update Jexl link when it gets Maven-ized -->
+
+<a href="http://jakarta.apache.org/commons/">Jexl</a> as well as others like XPath via
+<a href="http://jaxen.org">Jaxen</a>.
+</p>
+</section>
+
+<section name="How it works">
+<p>A Jelly script is an XML document.
+XML elements can be bound to <i>Tags</i> (or should that be Jelly Beans ;-) which are typically
+just Java Beans which also implement Jelly's
+<a href="apidocs/org/apache/commons/jelly/Tag.html">Tag</a> interface.
+</p>
+
+<p>
+When a Jelly script is run, the properties of the Jelly Bean are configured using the XML attributes.
+Then the tag is run by calling its <i>doTag()</i> method.
+The Tag can then perform some processing and invoke its body (the contents of the XML element)
+if it wishes, however many times it wants. So Jelly Tags are very like JSP custom tags and Ant Tasks.
+</p>
+
+<p>
+Also Jelly Tags can be defined at runtime in dynamic Jelly script using the <i>define</i> tag
+library so that simple yet powerful macros can be made very easily.
+</p>
+</section>
+
+<section name="JSTL">
+<p>
+<a href="http://java.sun.com/products/jsp/jstl/">JSTL</a>
+is the JSP Standard Tag Library which is being standardized through the JCP process.
+</p>
+
+<p>
+Jelly implements a collection of JSTL tags to peform core features like
+evalute expressions, conditional branching and looping, as well the processing of beans, XML, XPath and SQL.
+</p>
+
+<p>
+Jelly can act as a stand alone lightweight engine for running JSTL
+scripts which can be run from the command line or from Ant or that can be easily
+embedded into SOAP services, Servlet engines, JMS MessageListeners or your own software.
</p>
+</section>
+<section name="Ant">
+<p>
+There is a JellyTask for calling Jelly from
+<a href="http://jakarta.apache.org/ant/">Ant</a>
+as well as a Jelly tag library for calling Ant Tasks from inside a Jelly script!
+Jelly's support for the Expresssion Language in JSTL, which looks very like Ant's
+own expresssion language, means that Ant properties can be used inside Jelly scripts seamlessly.
+</p>
+
+<p>
+So Jelly can be a scripting engine for Ant tasks which can be easily integrated into your Ant build.
+</p>
+</section>
+
+
+<section name="XML and Web Services">
<p>
Jelly is based on an XML event pipeline architecture (SAX), like Cocoon, rather than being purely text
based like JSP and Velocity. This means that Jelly tags can consume XML events and emit them. Each
-Jelly custom tag can then act as an XML source, result or transformation.
+Jelly Tag can then act as an XML source, result or transformation.
+Also because this is an XML event pipeline, XML can be processed very efficiently without redundant
+runtime parsing.
</p>
-<p>We hope Jelly can be both an XML processing and transformation engine,
+<p>
+In addition there is a tag library called the Jelly Stylesheet Library (JSL) for
+performing XSLT-style declarative processsing of XML documents using a pattern match approach.
+</p>
+
+<p>
+Using the dynamic tag creation features of the <i>define</i> tag library we can easily script SOAP services using
+a simple tag based macro language.
+</p>
+
+<p>
+For example the following piece of Jelly script could evaluate its dynamic
+body (which can contain any Jelly tags, JSTL or Ant tasks) then convert the body into the correct SOAP message, call a SOAP service
+then format the results neatly as XML.
+</p>
+
+<pre>
+<babelfish:translate from="en" to="fr">
+ Welcome <j:expr value="${user.name}"/> to Jelly!
+</babelfish:translate>
+</pre>
+
+<p>
+A Jelly script is an XML document, which means that Jelly can process itself.
+All of these things make Jelly a good choice for for working with XML and Web Services.
+</p>
+
+</section>
+
+<section name="Other uses">
+<p>We hope Jelly can be both generic and powerful XML processing and transformation engine,
a web and XML based scripting engine as well as a unit testing framework for
testing web applications and web services.
-In addition Jelly can act as a stand alone lightweight engine for running JSTL
-scripts which can be run from the command line, inside SOAP services or from Ant.
</p>
</section>
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