Visualforce - infinite redirection loop

Question

I have the following Visualforce page that overrides the "View" action of a standard object:

<apex:page standardController="Opportunity" extensions="OpportunityDispatcherCx" action="{!redirect}"/>

This is my controller:

public class OpportunityDispatcherCx {
    // Opportunity Variable
    Opportunity oOpportunity {get;set;} 

    public OpportunityDispatcherCx(ApexPages.standardController stdController) {
        oOpportunity = [Select Id, Amount
                        From Opportunity
                        Where Id = :stdController.getId()];
    }

    public PageReference redirect() {
        // Construct a redirection url
        String redirectUrl = '';

        // Make your checks
        if(oOpportunity.Amount < 100) {
            redirectUrl = '/apex/errorPage?id=' + oOpportunity.Id;
        }else {
            redirectUrl = '/' + oOpportunity.Id;
        }

        // Set a pageReference for redirection
        PageReference pageRef = new PageReference(redirectUrl);

        // Return it for the redirection
        return pageRef;
    }
}

However, when an Opportunity amount is over 100, the code will be called again and again for every successful redirection, leading to infinite recursion. What is the solution?

Answer 1

You need to handle this in your code, to make sure it doesn't redirect second time.

    //Just check if your page contains extra parameter retur null
    if(Apexpages.currentpage().getparameters().containsKey('noredirect'))
         return null;
    // Construct a redirection url
    String redirectUrl = '';

    // Make your checks
    if(oOpportunity.Amount < 100) {
        redirectUrl = '/apex/errorPage?id=' + oOpportunity.Id;
    }else {
        redirectUrl = '/' + oOpportunity.Id+'?noredirect=true';
    }
    //this code will only work first time.
    // Set a pageReference for redirection
    PageReference pageRef = new PageReference(redirectUrl);
    // Return it for the redirection
    return pageRef;

or better as you are already on detail page so instead of redirecting, Just return null.

    // Make your checks
    if(oOpportunity.Amount < 100) {
        redirectUrl = '/apex/errorPage?id=' + oOpportunity.Id;
    }else {
        return null; //just return from here
    }

    // Set a pageReference for redirection
    PageReference pageRef = new PageReference(redirectUrl);

    // Return it for the redirection
    return pageRef;