Display different VF Pages depending on field's value

Question

I have a requirement where I have to display different pages depending on a Lead's custom field's (Score__c) value. Kindly help me with a sample code which states that if the value of Score__c is 'A', display /apex/PageA and If value of Score__c is 'B' then display /apex/PageB.

Here is the Controller:

public PageReference getScoreA  () {
    PageReference pageRef = new PageReference( '/apex/PageA' );        
    pageRef.setRedirect( true );
    return pageRef;
}   
public PageReference getScoreB () {
    PageReference pageRef = new PageReference( '/apex/PageB' );        
    pageRef.setRedirect( true );
    return pageRef;
}

public PageReference ViewProposal() {
  PageReference pageRef = null;
  List<Lead> LeadList = [Select id, Name ,Score__c FROM Lead];
  if (record.Score__C== 'A' {              
            pageRef = this.getScoreA();
    } else if (record.Score== 'B' {

           pageRef = this.getScoreB();
    }      
   return pageRef;
  }

Page-

 <apex:pageBlock>
    <apex:pageblockButtons>
        <apex:commandButton title="Submit" action="{!ViewProposal}" value="Submit" />            
    </apex:pageblockButtons>
  </apex:pageBlock>

Answer 1

Using several pages and the rendered attribute, you could do this relatively easily. Simplest form of that would look like this:

<apex:page standardController="Lead" ...>

  <apex:include pageName="pageA" rendered="{!Lead.Score__c == 'A'}"/>
  <apex:include pageName="pageB" rendered="{!Lead.Score__c == 'B'}"/>

</apex:page>

You would then need the pages called pageA and pageB respectively. But you probably don't need to do this as you can just do it on different components of your VF page like this:

<apex:page standardController="Lead" ...>

  <apex:pageBlock rendered="{!Lead.Score__c == 'A'}">
    <!-- one page block that works when score is A -->
  </apex:pageBlock>
  <apex:pageBlock rendered="{!Lead.Score__c == 'B'}">
    <!-- another page block that works when score is B -->
  </apex:pageBlock>

</apex:page>

In all these cases, this bit: {!Lead.Score__c == 'B'} is essentially a formula, resulting in a Boolean (true/false) value. If true, show this component and all content. If false, don't.

This is one of Visualforce's strengths: data-driven rendering of UI components. You can do this on as big a scale as you want (like the page blocks above), or on as minute a scale (a single field).

There are even ways to dynamically do this as values change using partial page refresh. There are lots of examples of this including the answer linked above.

EDIT: While I realize this is not a direct reply to the request to have a navigation that goes either to one page or another, I would recommend this approach. There are some advantages along the lines of maintainability namely:

• There are fewer artifacts to maintain. By putting the logic in a single page, you have one place to go to change this when it is required in the future
• If you have the data driven logic in the navigation, if you add a third value, you need to not only add another page, but you also must know to change all navigation points in the future.
• The logic of which fields to display is all encapsulated in this page, meaning anytime any developer chooses to navigate to this page, it should behave according to your requirements. With your architecture, a developer must know that PageA is for one data value, and PageB is for another.

Answer 2

You could simplify your controller to be as shown below

public PageReference ViewProposal() {
  PageReference resPg;
  // extensible map as you add scores
  Map<String,PageReference> scoreToPgRefMap = 
        new Map<String,PageReference> {'A' => new PageReference('/apex/PageA'),
                                       'B' => new PageReference('/apex/PageB')};

  Lead l = [select id, score__c from Lead where id = :someLeadId];
  if (scoreToPgRefMap.containsKey(l.score__c) {
      resPg =  scoreToPgRefMap.get(l.score__c);
      resPg.setRedirect(true);
  } 
  return resPg;
}

I note that the code you posted references a variable called record which isn't declared - presumably you want to reference the Lead associated with the page that the commandButton is on. It wasn't clear if that button was on the Lead page - if so, then you don't need to query the Lead as you already have the lead in scope within your constructor.