Monday, August 3, 2015

HOW TO PASS PARAMETERS BETWEEN TWO VISUALFORCE PAGES HAVING SAME CONTROLLER

Let me discuss about another use case where it is required to pass information from one VisualForce page to another VisualForce page while both the VisualForce pages are sharing the same controller. I know this is a very basic example, but I would like to include this use case as part of my previous post - HOW TO PASS PARAMETERS TO VISUALFORCE PAGES AND BETWEEN PAGES. Special thanks to Joseph McNulty for pointing this to me.

To start with let us first create the common controller – SingleController


Here is the first VisualForce Page – FirstPage.


Here is the second VisualForce Page – SecondPage.


As you can see from FirstPage, I am setting the name to the controller variable - name and then clicking on the commandButton,  goToSecondPage() method from controller is getting called. This goToSecondPage() method is returning a PageReference to the SecondPage. The point to notice here is that inside the method goToSecondPage(), I am making the setRedirect(false). I will explain what will happen if I set it to true later in this post. So what is happening after clicking on the button is that a SecondPage is getting displayed with Welcome message. But another interesting thing to notice here is that URL is not getting changed i.e. URL is still pointing to /apex/FirstPage though the content is from SecondPage.

So before going further inside, I hope you now know how you can pass information from one VisualForce page to another where both the pages are having common controller.

Now the interesting part –
With setRedirect(false) – redirect is happening through a server side redirect and the URL is not getting changed. In our case, since the target page is using the same controller that is why the view state is preserved. As a result, in the new page i.e. SecondPage; you can see the name after Welcome message.
But with setRedirect(true) - redirect is happening through a client side redirect and the URL is getting changed. View state is also not preserved and you will not see the name after Welcome message.

I am thinking of a more detailed post on setRedirect method. It may look very simple, but it is basically doing many interesting stuffs at the back stage. As a developer, we should understand this method very clearly.
If you have any feedback, please pass it to me. I really appreciate it. Thanks.

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