Accessing a list of params in controller

[jeeper]

Hello together,

Im very new to grails (1.3.7) so please be patient :-)

I have a gsp where I have various checkboxes. A user can click on them and then send his answer to a controller. The controller is receiving this request correctly.

My problem is, that, for working with what the user chose, I have to check every parameter - to see if this checkbox was really checked. Thats really cumbersome and doesnt work very well, because the page displaying the checkboxes is dynamic - so the checkboxes which can be clicked are dynamic too. In my controller I dont know for which params I have to check then.

Is there any possibility to receive a list of all checkboxes (or better: all checked checkboxes) in my controller? I researched but didnt find an answer!

Thanks for answering! :-)

[jeeper]

Ive got the answer:

params.name.each{i->
            System.out.println(i);
}

really very easy

[pledbrook]

What does your GSP form look like? Detecting a checkbox on the server side is tricky and would make your code heavily dependent on implementation detail. I recommend you either use a naming convention for your checkbox tags and use that to distinguish between them:

for (p in params) {
    // If parameter name begins with 'checkBox', it's a checkbox field.
    if (p.key.startsWith("checkBox")) {
        ...
    }
}

Alternatively, add a hidden input field for each checkbox whose value contains the name of the checkbox element.

[jeeper]

thanks for your answer! why do you think that my solution is not good? I mean, I only get the checkboxes who were checked/clicked from the user, I dont think thats a bad idea? thank you :-)

[pledbrook]

What does your GSP look like?

[jeeper]

Snippet:

  <g:form action="startSimu" controller="lpicSimulator">

    <g:if test="${questionsList101 != null && !questionsList101.isEmpty()}">  Bereich 101:<br/>
      <g:each in="${questionsList101}" var="elem" status="i">
        <g:checkBox name="eins" value="${questionsList101[i].id}" checked="false"/>${i+1}<br/>
      </g:each>
      <br/>
    </g:if>

    <g:if test="${questionsList102 != null && !questionsList102.isEmpty()}">
      Bereich 102:<br/>
      <g:each in="${questionsList102}" var="elem" status="i">
        <g:checkBox name="zwei" value="${questionsList102[i].id}" checked="false"/>${i+1}<br/>
      </g:each>
      <br/>
    </g:if>

    <g:if test="${questionsList103 != null && !questionsList103.isEmpty()}">
      Bereich 103:<br/>
      <g:each in="${questionsList103}" var="elem" status="i">
        <g:checkBox name="drei" value="${questionsList103[i].id}" checked="false"/>${i+1}<br/>
      </g:each>
      <br/>
    </g:if>
......

params.eins.each{i-> cacheService.questionList.add(i); }
        params.zwei.each{i-> cacheService.questionList.add(i); }
        params.drei.each{i-> cacheService.questionList.add(i); }

I think its very easy, because with the second snippet, I only get the checkboxes which were checked... Of course, Ive got to know the name of the checkbox-list, but with your solution this would be similiar, wouldnt it?

thank you