On 28/10/2011 00:39, Thorsten Scherler wrote:
Hi all,
what is the recommended way to implement presentation logic in c3? JX was our
former choice but I could not find it in c3.
What should we use to implement simple presentation logic like we did with jx?
What are people using? Or do I need to migrate jx?
Hi Thorsten,
this sounds like something we started discussing about a while ago [2]:
as you can see from there, we ended up by not porting JX-related (or
Velocity-related) components.
Personally, I think that StringTemplate should be enough for the moment;
anyway, maybe not now, I still do believe that Cocoon 3 would really
benefit from something like JX.
I tried to use the "string-template" component but I am running into a problem
when using $if(boolean)$.
I am ATM integrating Apache Shiro, a security framework that performs
authentication, authorization, cryptography, and session management, into c3
and want to use something in the spirit of their taglibs
<shiro:notAuthenticated>
Please<a href="login.jsp">login</a>.
</shiro:notAuthenticated>
So what I did is I wrote a ShiroInterpreter implements LanguageInterpreter that
can extract this info.
However the interface LanguageInterpreter defines the return type to String.
<map:transform type="string-template">
<map:parameter name="isUser" value="{shiro:authenticated}"/>
</map:transform>
will fail then interpreting
$if(!isUser)$
<a href="/logout">/logout</a>
$else$
<a href="/login">/login</a>
$endif$
with
...
Caused by: org.stringtemplate.v4.compiler.STException: null
at
org.stringtemplate.v4.compiler.Compiler.reportMessageAndThrowSTException(Compiler.java:213)
~[ST4-4.0.4.jar:na]
If I use only $isUser$ I get the correct value. Reading "Conditional
subtemplates" [1]
"You may only test whether an attribute is present or absent, preserving
separation of model
and view. The only exception is that if an attribute value is a Boolean object, it
will test it for true/false."
I think you've hit a bug of StringTemplate transformer: see the attached
patch (for cocoon-sample in C3 sources) using conditional and boolean
value from sitemap; ST generator works well and ST transformer raises an
exception similar to the one reported above.
So for me the exception either mean we do not support $if(condition)$ or that
the compiler do not likes that $isUser$ is a String and not a boolean.
Are you sure that $isUser$ is a String? Shouldn't it be a boolean
instead [3]?
TIA for any feedback!
salu2
[1] http://www.cs.usfca.edu/~parrt/course/601/lectures/stringtemplate.html
[2]
http://old.nabble.com/-C3--Passing-parameters-from-sitemap-to-generator-td31971810.html
[3]
https://shiro.apache.org/static/current/apidocs/org/apache/shiro/subject/Subject.html#isAuthenticated%28%29
--
Francesco Chicchiriccò
Apache Cocoon Committer and PMC Member
http://people.apache.org/~ilgrosso/
Index: cocoon-sample/src/main/resources/COB-INF/string-template/template.xml
===================================================================
--- cocoon-sample/src/main/resources/COB-INF/string-template/template.xml (revisione 1190180)
+++ cocoon-sample/src/main/resources/COB-INF/string-template/template.xml (copia locale)
@@ -24,5 +24,11 @@
<body>
<h3>StringTemplate demo</h3>
<p>parameter=$parameter$</p>
+ <p>booleanParameter=$booleanParameter$</p>
+$if(!booleanParameter)$
+<p>expression evaluated to true</p>
+$else$
+<p>expression evaluated to false</p>
+$endif$
</body>
</html>
Index: cocoon-sample/src/main/resources/COB-INF/sitemap.xmap
===================================================================
--- cocoon-sample/src/main/resources/COB-INF/sitemap.xmap (revisione 1190180)
+++ cocoon-sample/src/main/resources/COB-INF/sitemap.xmap (copia locale)
@@ -552,6 +552,7 @@
<map:match wildcard="string-template/generator">
<map:generate type="string-template" src="string-template/template.xml">
<map:parameter name="parameter" value="A value"/>
+ <map:parameter name="booleanParameter" value="{jexl:cocoon.request.isSecure()}"/>
</map:generate>
<map:serialize/>
</map:match>
@@ -559,6 +560,7 @@
<map:generate src="string-template/template.xml"/>
<map:transform type="string-template">
<map:parameter name="parameter" value="Another value"/>
+ <map:parameter name="booleanParameter" value="{jexl:cocoon.request.isSecure()}"/>
</map:transform>
<map:serialize/>
</map:match>
