Re: dynamic cForm generation

[Jason Johnston]

Philippe Gauthier - INSERM SIRH wrote:
  Hi Rashel,
U shouldn't use a dynamic form definition, because it means for each 
call, cocoon will have to compile a new form and can't use any caching.
I did the same mistake using xslt transformation to generate the 
definition (using pipelineToStream to save it to disk temporary) and it 
killed the JVM eventually .
And that's why the form instantiation function takes only system file.

Instead u have to understand the binding concepts of forms an redesign a 
or some generic forms definition and templates with more complex widgets.
Then u'll be have able to fill thoses forms with dynamic data.
I hope I gave U the right pointers, sorry for my english.

I agree that it's preferable to have a static form definition with 
dynamic widgets that modify the structure of the form at runtime.  But 
there are cases where that's not possible, so true dynamic form creation 
is a useful tool to have.

What you say about caching the form definition is also true but is only 
an issue if the pipeline that generates it is not cacheable.  If all of 
that pipeline's components are cacheable then the form definition is 
cached IIUC.

Rashel, what you are looking for I believe is this:

  var form = new Form("cocoon:/my-dynamic-form-def-pipeline");

That uses the result of a Cocoon pipeline to build the form definition. 
 Unfortunately, currently the Form constructor does not allow passing 
flow attributes as a second argument; there is an open issue in Jira for 
adding that feature: https://issues.apache.org/jira/browse/COCOON-1418

In the absence of that feature you can pass along the data in another 
way, for instance setting it as an attribute on the request.  Or you 
could try applying the patch attached to that Jira issue.

Finally, if you're using JX to generate the definition XML, I'd strongly 
suggest using jx:cache-key and jx:cache-validity to control the caching 
of the result if possible, that way you'll avoid the performance/memory 
issue Philippe warned of.  This feature might only be available in the 
'newjx' version of JXTemplateGenerator; details at 
http://wiki.apache.org/cocoon/JXTemplateGenerator

--Jason


regards,

Philippe

Rashel Shehata a écrit :
Hi Bart,
Ok so  to create the form definition xml the jx generator uses the 
following xml file:
I pass it an array object (questionRegistry.getAllQuestions()) that 
contains a list of all the questions to be created in the form

<?xml version="1.0"?>
<fd:form xmlns:fd="http://apache.org/cocoon/forms/1.0#definition";
         xmlns:i18n=" http://apache.org/cocoon/i18n/2.1";
    xmlns:jx="http://apache.org/cocoon/templates/jx/1.0";>


<fd:widgets>
  
   <jx:forEach var="question" items="${questions}">
  
   <jx:choose>
 <jx:when test="${question.responseType == 'multivalue-field'}">
  <fd:multivaluefield id='${question.ID}' 
required='${question.required}' state='${question.state}'>
    <fd:label>     ${question.label} </fd:label>
    <fd:help>${ question.help}</fd:help>
       <fd:hint>${question.hint}</fd:hint>
     <fd:datatype base="long"></fd:datatype>
     <fd:selection-list>
     <jx:forEach var="response" items="${ question.responses}">
     <fd:item value='${response.ID}'>
        <fd:label>${response.label}</fd:label>
        </fd:item>
  
   </jx:forEach>
   </fd:selection-list>
  </fd:multivaluefield>
  
  </jx:when>
 
  <jx:when test="${question.responseType == 'checkbox'}">
  <fd:booleanfield id='${question.ID}' required='${ 
question.required}' state='${question.state}'>
    <fd:label>     ${question.label} </fd:label>
    <fd:help>${question.help}</fd:help>
       <fd:hint>${question.hint }</fd:hint>
   </fd:booleanfield>

  </jx:when>

 <jx:otherwise>
   <fd:field id='${question.ID}' required='${question.required}' 
state='${question.state}'>
       <fd:label>     ${question.label} ${question.responseType } 
</fd:label>
    <fd:help>${question.help}</fd:help>
       <fd:hint>${question.hint}</fd:hint>

...

  </fd:field>
 </jx:otherwise>  
   </jx:choose>
   </jx:forEach>
 </fd:widgets>
 </fd:form>
 

 

the jx generator then outputs the serialized xml to the browser, where 
the xml is in correct cForm syntax... it's similar for the 
form template also...

I now want to do use both serialized xml and feed it back into a  
pipeline entry so i can view the generated form as a HTML form...

 

I hope this made my problem clearer..

 

Thanks heaps

On 4/18/07, *bart remmerie* <[EMAIL PROTECTED] 
<mailto:[EMAIL PROTECTED]>> wrote:

    Dear Rashel,

    Could you give an example/snippet of one of these .xml files ?

    Bart

    2007/4/18, Rashel Shehata <[EMAIL PROTECTED]
    <mailto:[EMAIL PROTECTED]>>:

        Hey,
         
        I'm trying to generate cocoon forms dynamically. atm I create
        the cForm model xml dynamically using jx generator; this is
        what i have:
         
        in my flowscript:
          cocoon.sendPage("form_model-pipeline.xsp" ,
             {questions: questionRegistry.getAllQuestions()});
         
        and in my pipeline:
        <map:match pattern="*-pipeline.xsp">
               <map:generate type="jx" src="forms/{1}.xml"/>
               <map:serialize type="xml"/>
             </map:match>
         
        the jx generator creates a cForm xml model in correct syntax
        and is outputted as XML to the browser...
         
        what im trying to do now is feed this newly generated xml
        model to the pipeline so that a Form will be generated and
        viewed, however i'm not really sure how to do this, or which
        part of cocoon docos i sould be reading...
        How do I dynamically generate input content to be used as a
        source in the sitemap??
         
         
        Any help would be appreciated...

         




    -- 
    Bart Remmerie 




--
Philippe Gauthier
INSERM
DRH - SIRH
Tel: 01.44.23.62.57



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