SSJS Platform.Response.Redirect() throws unknown error: Error in Application

Question

I am trying to understand why the following is happening:

<script runat="server">
    try{
        Platform.Response.Redirect('http://www.google.com');
    } catch(e) {
        Platform.Response.Redirect('http://www.yahoo.com');
    }
</script>

This code triggers the catch redirect. Why does it trigger the redirect of the catch block instead of the redirect in the try block. If I redirect from the catch block to a handler page and pass "e" I can see the following error:

{"message":"Error in the application.","description":"ExactTarget.OMM.AMPScriptRedirectException: Error in the application. - from Jint\r\n\r\n"}

If I remove or comment out the catch redirect, the redirect to google.com works fine. If I change the try block to anything but a redirect, it also works as expected. It seems only happen when there is a redirect in the try and catch block.

The above is the entire code.

Any ideas anyone?

Edit: There is another post regarding the same issue from earlier this year but with no response: https://stackoverflow.com/questions/60343379/ssjs-platform-response-redirect-throws-error-in-try-catch-statement

Answer 1

So, this is a known issue in .Net (which is what is used for rendering SFMC SSJS). Using Redirect will throw a Thread Abort Exception. Which I believe is what @SamWhitmore was stating in the official SFMC statement he provided. And as we do not have the control on catching exceptions that you do with .Net, we have to think outside the box.

The best way to get around this that I have found is to place a conditional in your catch statement. By putting the condition in, you can have it where the redirect does not appear in the catch if the error is "ExactTarget.OMM.AMPScriptRedirectException: Error in the application. - from OMMCommon\r\n\r\n" so then the try will run successfully as the redirect will no longer exist in the catch to cause the above stated issues.

Something like:

<script runat="server">
    var redirect = 'https://google.com'

    try{
          Platform.Response.Redirect(redirect + '?s=pass')
    } catch(e) {
        var desc = e.description; //Pulls the description from error object
        if(desc.indexOf("ExactTarget.OMM.AMPScriptRedirectException") > -1) {
          Platform.Response.Write(desc) //This is arbitrary as will not be run
        } else {
          redirect = 'https://yahoo.com'
          Platform.Response.Redirect(redirect)
        }
    }
</script>

For testing I had both go to google with the try adding the parameter of s=pass and failure (catch) pulling in the parameter of e that contains the error description. This way if there was an error, like writing Plaatform instead of Platform it would redirect with the error description inside the parameter or e, but if all was right in the try part, it would hide the redirect inside the conditional, allowing the try to run correctly.

Edited to include indexOf instead of direct string match and to change redirect in catch to a different URL to remove any confusion on including error description inside of query parameter of redirect URL.

Answer 2

I talked with one of the developers of SSJS and he told me:

Redirect works by throwing an exception, so if it is inside a try it will indeed always end up in the catch statement. The one in the catch will overwrite the location set by the first one, and generate a new exception. It is similar to the ThreadAbort exceptions generated when calling the default Response.Redirect method in .net.

So, it's functioning as designed, which doesn't necessarily help you out if you've got a redirect buried in a function or other code that then gets called inside a try block. But it's at least an answer.

Answer 3

Refer to the SSJS Redirect function syntax.

Try the below code -

<script runat="server" language="javascript">
Platform.Load("core", "1.1.1");     // Load core library

try {
    Redirect("http://www.google.com",true); 
 } 
 catch(e) {
    Redirect("http://www.yahoo.com",true);
} 
 </script>

Answer 4

I do not really know why - but I know how to restructure the code that it will work:

<script runat="server">
    var redirect = 'http://www.google.com'
  
    try{
        //do your stuff here
    } catch(e) {
        redirect = 'http://www.yahoo.com'
    }
  
    Platform.Response.Redirect(redirect)
</script>

Answer 5

The answer from Daniel Koch works pretty well and I can see no logical explanation why this is happen but the Redirect always throws an error. Instead of re-writing your code, I come up with this solution based of Daniel's answer:

<script runat="server" language="javascript">
Platform.Load("core", "1.1.1");

try {

    // do stuff
    try{
        Redirect("http://www.google.com", false);    
    } catch(e) {}

} catch (e) {
    Redirect("http://www.yahoo.com", false);
}
</script>