Redirect to Next Typeform from Optional Query String Parameter

Hello,

I have a hidden field defined: next_typeform_id

I would like to have two endings to the current survey:

1. if next_typeform_id is empty or missing, just load a default end screen
2. if next_typeform_id exists, then redirect to that typeform (e.g., subdomain.typeform.com/to/next_typeform_id)

I can edit the logic on the final question of my Typeform survey to say:

if next_typeform_id:

• is equal to
• is not equal to
• begins with
• ends with
• contains
• does not contain

But there is not an option that I really want (“is defined” or “string length < 1” or something like that).

Am I missing something?

The only hack that I can think of is to have a 26-step logic that checks:

if next_typeform_id contains a OR

if next_typeform_id contains b OR

…

if next_typeform_id contains z

I am still very new to Typeform, so I am just hopeful that there is a better way.