Customize/parametrize sessionError template per MetadataProvider

[Cantor, Scott]

> I am interested if it is possible to configure sessionError per
> MetadataProvider?

No. Only based on content settings or at the level of an application / override.

> Bigger scope: we as downstream service provider for CUSTOMER1...N need
> to provide friendly error message to end users ("customers of our
> customers"), which should be something like "Dear user, your session has
> expired, please do logout and login. If the issue still persists, contact
> service at CUSTOMER[1..N].com"

Error handling is almost always better handled by the application or if you have to by using redirectErrors to pick them up via scripts.

Note that the IdP entityId is exposed in the templates if it's known, so in theory you could implement ugly conditionals with the shibmlpif feature, but it's not really very practical at scale.

-- Scott