Hi,
I am working on creating question answer app, where multiple choice questions are being displayed. I have used radio button to display options for particular questions. Whenever i am assigning ID to radio it is assigned as null.

Please see below apex code where ID is assigned to radioAns string variable at line no 19:

1. private PageReference fillWrapper (Question__c pQuestion, Set<String> pAnsIdSet) {
2.       system.debug('Called in fillwrapper');
3.        List<SelectOption> selOptList = new List<SelectOption> ();
4.        List<AnsWrapper> listOptions = new List<AnsWrapper> ();
5.        String charector;
6.        for (Option__c option : [SELECT Id, Correct_Answer__c, Option__c
7.                               FROM Option__c
8.                                WHERE Question__c = : pQuestion.Id]) {
9.            charector = charector == null? 'A': fetchNextChar (charector);
10.           AnsWrapper ans; 
11.            if (pQuestion.Total_Correct_Answers__c > 1) {
12.                if (pAnsIdSet.contains (option.Id))
13.                    ans = new AnsWrapper (option, true, charector);
14.               else
15.                    ans = new AnsWrapper (option, false, charector);
16.           // listOptions.add (ans);
17.            } else {
18.                if (pAnsIdSet.contains (option.Id))
19.                    radioAns = String.valueOf(option.Id);
20.                    system.debug('RadioAns in fillWrapper '+radioAns+' Option.Id in fillwrapper->'+option.Id);
21.                    ans = new AnsWrapper (option, true, charector);
22.                    ans = new AnsWrapper (option, false, charector);
23.                    selOptList.add (new SelectOption (option.Id, option.Option__c));
24.            }
25.            System.debug ('listOptions ==> '+ listOptions);
26.            listOptions.add (ans);
27.        }
28.      //  if (!listOptions.isEmpty ())
29.            mainWpr = new MainWrapper (pQuestion, null, listOptions);
30.      //  else
31.        //    mainWpr = new MainWrapper (pQuestion, selOptList, null);
32.        return null;
33.    }



Below is the VF page code where radioAns is used:

<apex:outputPanel rendered="{!mainWpr.listOption!=null&& mainWpr.question.Total_Correct_Answers__c==1}">
<apex:repeat value="{!mainWpr.listOption}" var="opt">
<div style="width:100%">
<apex:outputPanel >
<div style="width:0px; float: left; margin-top: 10px;">
<apex:outputText value="{!opt.serialNo}"/>
</div> <div style="width:90%;">
<apex:selectRadio layout="lineDirection" value="{!radioAns}" onclick="setRadioParam ('{!opt.option.Id}');">
<apex:selectOption itemLabel="{!opt.option.Option__c}" itemValue="{!opt.option.Id}"/>
</apex:selectRadio>
</div> </apex:outputPanel>
<apex:actionfunction name="setRadioParam" reRender="theForm">
<apex:param id="radioAns" name="radioAns" value="" assignTo="{!radioAns}"/>
</apex:actionfunction>


As per the apex code i tried to debug the values of option.Id and radioAns at line no 20 and below are the logs for the same:

13:25:35:058 USER_DEBUG [74]|DEBUG|OptionID: a027F00000D8xeFQAR

13:25:35:058 USER_DEBUG [74]|DEBUG|OptionID: a027F00000D8xeRQAR

13:25:35:059 USER_DEBUG [74]|DEBUG|OptionID: a027F00000D8xeSQAR

13:25:35:094 USER_DEBUG [143]|DEBUG|Called in fillwrapper

13:25:35:099 USER_DEBUG [161]|DEBUG|RadioAns in fillWrapper null Option.Id in fillwrapper->a027F00000D8xeNQAR

13:25:35:100 USER_DEBUG [166]|DEBUG|listOptions ==> ()

13:25:35:101 USER_DEBUG [161]|DEBUG|RadioAns in fillWrapper null Option.Id in fillwrapper->a027F00000D8xfWQAR




Can someone help me to figure out why null value is being assigned to radioAns when value is present in option.Id?