External dynamic participant IDs and Redirect

[aline....@gmail.com]

Hi,

I have my project running on heroku. The survey provider (CINT) will provide me with participant IDs which I will have to integrate into my app and then again redirect to them at completion. The survey provider will invite participants to the survey and will provde them with a project-specific ID which will be added to my URL, as an example:

http://aline-test.herokuapp.com/join/moluduna?participation_id=test1111

Once the participant completes the study he/she should be redirected with the initial ID to the survey provider, with the following link:

https://gateway.gapfish.com/routings/participation_id/finish/completed

Would anyone mind sharing some specific code which I could use in order to achieve this? I have so far only included the OTREE_REST_KEY in my heroku settings, but apart from this I can't figure out how to best set this up (even after reading the code regarding Profilic App). Could anyone provide me with a hint?

Thank you,

Aline

[David]

Hi Aline,

As far as I know, participant_label is the only GET parameter that oTree accepts and saves automatically. The URLs that your survey provider sends to the participants should look like this (with 'participant_label' instead of 'participation_id'):

http://aline-test.herokuapp.com/join/moluduna?participant_label=test1111

Then the attached ID should be available in the label attribute of the participant object, so you can include it in the completion link on your last page. For example:

<a href="https://gateway.gapfish.com/routings/{{ participant.label }}/finish/completed">Complete the study</a>

I hope this helps a little.

Best,

David

[aline....@gmail.com]

Thank you, this is working! I have another question: I would like to implement a similar approach to automatically handle the number of participants per treatment, when a treatment is already full, participants should be redirected. I included the following:

In my settings.py:

SESSION_FIELDS = ['num_participants_finished']

In my init.py

class SorryFull(Page):
@staticmethod
def is_displayed(player):
session = player.session
return session.num_participants_finished > 100

In my template:

<a href="https://gateway.gapfish.com/routings/{{ participant.label }}/finish/quota_full">Bitte klicken Sie auf
folgenden Link.</a>

However, this is not working. Does anyone have an idea as to what could be the issue here?

Thank you!

Aline