Working with Fieldsets

Fieldsets are one of the feature that you may use to make your visualforce dynamic. They are dynamic and allows display of component on the VF page dynamically. We  can add, remove, or reorder fields in a field set to modify the fields presented on the Visualforce page without modifying any code. Fieldsets are not very new to Force.com, but I have a habit searching for syntax before writing one, so writing this one for my reference and all others like me ;) .

Below are some of the example to show how fieldsets can be used in VF page.

• Simplest example

<apex:page controller="Account_Con">   
   <apex:repeat value="{!$ObjectType.Account.FieldSets.AccountDetails}" var="f">    
    <apex:outputText value="{!myAccount[f]}" /><br/>   
   </apex:repeat>   
  </apex:page>   

• To render a PageBlocksection

 <apex:page controller="Account_Con">  
   <apex:pageBlockSection>  
        <apex:repeat value="{!$ObjectType.Account.FieldSets.AccountDetails}" var="f">    
            <apex:outputField value="{!myAccount[f]}" />   
        </apex:repeat>   
   </apex:pageBlockSection>  
  </apex:page>   

• To render a PageBlockTable

 <apex:page controller="Account_Con">  
   <apex:pageBlockSection>  
        <apex:pageBlockTable>  
             <apex:repeat value="{!$ObjectType.Account.FieldSets.AccountDetails}" var="f">    
                 <apex:column value="{!myAccount.Contacts[f]}" />  
             </apex:repeat>  
     </apex:pageBlockTable>         
   </apex:pageBlockSection>  
  </apex:page>   

All the above listed example dynamically display the records from the fieldset but what about the controller?

we can't just hardcode the queries here.To further extend the solution grab the code for the AVCommonUtil Class that generates query from fieldset/s.

Solution : 

You can use the util class to generate query dynamically from the fieldsets.

public class Account_Con(){   
  public Account myAccount{get;set;}   
  public AccountCon(){   
      AVCommonUtils util = new AVCommonUtils();  
      String query = util.generateQueryFromFieldSet('Account','AccountDetails',null,'LIMIT 1');  
       accObj = database.query(query);    
  }   
}