SObject row was retrieved via SOQL without querying the requested field: Site__c.Home_Content_Body__c

Question

Site extenion class:

public with sharing class siteExtension {
    private ApexPages.StandardController controller;

    private Set<String> SiteFields = new Set<String>();

    public siteExtension (ApexPages.StandardController controller) {
        this.controller = controller;
        Map<String, Schema.SobjectField> fields = 
        Schema.SobjectType.Site__c.fields.getMap();

        for (String s : fields.keySet()) {
        // Only include accessible fields 
            if (fields.get(s).getDescribe().isAccessible() && 
                fields.get(s).getDescribe().isCustom()) {
                    SiteFields.add(s);
            }
        }
    }

    public  List<String> availableFields {
        get {
            controller.reset(); 
            controller.addFields(new List<String>(SiteFields));
                return new List<String>(SiteFields);
        }
    }
}

VF Page:

<apex:pageBlock title="{!Site__c.Name}">
    <apex:repeat value="{!availableFields}" var="field">
        <h2><apex:outputText 
             value="{!$ObjectType['Site__c'].Fields[field].Label}"/></h2>
        <br/>
        <apex:outputText value="{!Site__c[field]}" /><br/><br/>

    </apex:repeat>
</apex:pageBlock>

Why do I get this error:

SObject row was retrieved via SOQL without querying the requested field: Site__c.Home_Content_Body__c

I followed the tutorial from https://developer.salesforce.com/docs/atlas.en-us.pages.meta/pages/pages_dynamic_vf_sample_custom.htm

Answer 1

The standard controller by default will query for all fields referenced directly on the page. However, if you reference them dynamically instead, you need to explicitly add them in your constructor. Note that this operation cannot be performed in a test.

I would reorganize your code slightly as well:

public List<String> availableFields { get; private set; }
public siteExtension (ApexPages.StandardController controller)
{
    availableFields = new List<String>();
    // populate via existing logic
    if (!Test.isRunningTest()) controller.addFields(availableFields);
}