PageReference: Redirect to built page

Question

Can I build some XML or JSON in Apex and then redirect to it from a method that returns a PageReference object?

public PageReference saveText() {
    PageReference p = new PageReference(someJSONObject);
    p.setRedirect(true);
    return p;
}

Is anything like this possible?

Answer 1

No, a PageReference isn't content, it's just a reference to some content, which Visualforce then redirects the user to. You could render your json in a Visualforce page and specify the mime type, for example:

<apex:page applyHtmlTag="false" showHeader="false" contentType="application/json" 
           controller="jsonTestController">
  {!jsonText}
</apex:page>

However, if you need to return JSON or XML in this manner, you would probably be better off using Apex REST to write a class that handles HTTP requests & responses directly, without invoking Visualforce. And since Apex REST exposes your class at a public URL, you can always return a PageReference to the URL from your controller if you have a use case that does require redirecting from a VF page to an API end point.