Visualforce | Multi Conditional Block Rendering

Question

I have a beginner's question..

I'm trying to make a VF PageBlOckSection render by the following logic:

---

IF Opportunity.Cancellation__c == TRUE AND Opportunity.Paid_Upfront__c == TRUE than Render 2 fields (Amount and Expiry Date)

IF Opportunity.Cancellation__c == TRUE AND Opportunity.Paid_Upfront__c == FALSE than Render 1 fields (Expiry Date)

IF Opportunity.Cancellation__c == FALSE AND Opportunity.Paid_Upfront__c == TRUE than Render 2 fields (Amount and Expiry Date)

IF Opportunity.Cancellation__c == FALSE AND Opportunity.Paid_Upfront__c == FALSE than do not render.

---

However I cannot make it work by the desired logic... I'm using this code: I'll appreciate any advice!

Thanks, Jonathan

---

        <apex:pageBlockSection title="Please fill the Expiry Date & Upfront Amount" columns="1" rendered="{!IF(AND(!Opportunity.Paid_Upfront__c == TRUE, !Opportunity.Cancellation__c != TRUE), TRUE, FALSE)}">

            <apex:inputField value="{!opportunity.Subscription_Expiry_Date__c}"/>
             <apex:inputField value="{!opportunity.Amount}"/>
        </apex:pageBlockSection>


        <apex:pageBlockSection title="Please fill the Expiry Date" columns="1" rendered="{!IF(AND(!Opportunity.Paid_Upfront__c == FALSE, !Opportunity.Cancellation__c != TRUE), TRUE, FALSE)}">

            <apex:inputField value="{!opportunity.Subscription_Expiry_Date__c}"/>
        </apex:pageBlockSection>


        <apex:pageBlockSection title="Please fill the Expiry Date" columns="1" rendered="{!IF(AND(!Opportunity.Paid_Upfront__c == TRUE, !Opportunity.Cancellation__c == TRUE), TRUE, FALSE)}">

            <apex:inputField value="{!opportunity.Subscription_Expiry_Date__c}"/>
             <apex:inputField value="{!opportunity.Amount}"/>

        </apex:pageBlockSection>


    </apex:pageBlock>
</apex:form>

Answer 1

Once you are in a Visualforce {! } expression fields are referenced without a further ! (and a ! prefix becomes shorthand for a NOT function). Also the result of the AND function is already a boolean so the surrounding IF is not needed.

So for "paid upfront and cancellation" and "not paid upfront and not cancellation" the expressions can be:

rendered="{! AND(Opportunity.Paid_Upfront__c, Opportunity.Cancellation__c) }"
rendered="{! AND(NOT(Opportunity.Paid_Upfront__c), NOT(Opportunity.Cancellation__c)) }"

If you prefer operators over functions, this equivalent form also normally works:

rendered="{! Opportunity.Paid_Upfront__c && Opportunity.Cancellation__c }"
rendered="{! !Opportunity.Paid_Upfront__c && !Opportunity.Cancellation__c }"