Allow email links for recipients that need to login externally to redirect accordingly

[Robert Lyon]

Currently when Mahara sends a message to a user there usually a link that they can click to view the related page / part of Mahara that the email relates to.

If the page needs authorisation the login box is displayed so they can login.

But it can be confusing to the user that needs to login externally.

Mahara currently has a $cfg->externallogin allowing the site to do a redirect on a site level to the correct login place . But if we have multiple institutions we may have multiple IdPs in play and so cannot do a redirect at the site level.

However if the user authorises to Mahara via an external source, eg SAML Identity Provider (IdP) or LTI webservice, it would be more useful to redirect the user directly to the external place so they can login there on a per user basis.

Also with SAML we can then redirect back and go to the URL that the email link wanted to go to.

To do this:

We will need to check that the user about to receive the email message has an external authinstance

And if so we will need to append something to the email url address, eg authinstance id

So that when they click on the link and go to Mahara it checks for that authinstance id and check internally to where they should be redirected to login

[Kristina Hoeppner (kris-hoeppner)]

https://reviews.mahara.org/#/c/10817/

[Mahara Bot (dev-mahara)]

Reviewed: https://reviews.mahara.org/10817
Committed: https://git.mahara.org/mahara/mahara/commit/2cf5911d56e76490665ea647c9d590339910b60c
Submitter: Cecilia Vela Gurovic (<email address hidden>)
Branch: master

commit 2cf5911d56e76490665ea647c9d590339910b60c
Author: Robert Lyon <email address hidden>
Date: Tue Mar 10 14:40:23 2020 +1300

Bug 1867203: Adding login email link

When receiving an email message and your auth method is external
- Working for SAML, XMLRPC where wantsurl returns you to right page
after login
- Working kinda for LTI where it redirects you to external site but no
return

Change-Id: I6bfc5f47140ec68ac8a9c4c3c69c9f836e056e98
Signed-off-by: Robert Lyon <email address hidden>