Question

Capturing Panel IDs via URL Parameters:
I want to pass a unique participant ID (e.g., panelID) through the survey URL (e.g., ?panelID=12345) and store it in the dataset for each respondent. I tried as per the instructions in the manual, and I do not understand how to define the variable to capture the panelID.

I used this code;
$panelCode = value('panelID');
put('panelCode', $panelCode);

But I got an error message

Could you please advise on how to write the URL in this case and how to write the PHP code to define the variable, or are there any other good practices in doing this?

Please help!

Thank you for your time.

Answer 1

The best solution would be to use the (new) "Panel Redirects" element, available as a question type. Unfortunately, the manual i noy et available in English, but the browser's features to translate pages, should do fine for the meantime.

I you want to stay with the traditional solution, make sure to embed a question "device and transferred variables" on the first page, and tell this question to read the PPID GET variable. You'll then have a new variable in the dataset - however, the name depends on the question ID and is shown in the question form.