New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

allow an ApplicationUser to be associated with multiple ApplicationTenancy's #47

Closed
danhaywood opened this Issue Nov 6, 2016 · 2 comments

Comments

Projects
None yet
2 participants
@danhaywood
Contributor

danhaywood commented Nov 6, 2016

Currently an ApplicationUser has an optional atPath, which specifies the (single) ApplicationTenancy to which they are related.

In Estatio we have a requirement for a user to be associated with multiple ApplicationTenancys, not necessarily hierarchical in nature. (There is also the requirement for a domain object to be associated within multiple ApplicationTenancy's, but that is application-specific and so doesn't impact this module).

What we are proposing is that we retain ApplicationUser#atPath, but remove the FK link to ApplicationTenancy. Instead, the interpretation of a user's atPath is application-specific; it could (as now) be considered to identify a single ApplicationTenancy, or it might instead be treated as a "specification" of a set of ApplicationTenancys to which the user belongs (similar to how a regex string identifies a set of matching values). Indeed, in Estatio we might well use a regex string.

This change will (in a minor way) break backward compatibility; ApplicationUser#getApplicationTenancy() will be removed, and the FK in the database will be removed.

To minimize disruption, though, we'll retain the ApplicationTenancy entity, as a way to enumerate all named application tenancies.

@oscarbou

This comment has been minimized.

Contributor

oscarbou commented Nov 7, 2016

In my experience, has all sense for me.

@danhaywood

This comment has been minimized.

Contributor

danhaywood commented Nov 8, 2016

From private email conversation with mwhesse:

The feature sounds interesting, and I already thought about wether a user shouldn't be able to belong to multiple tenants. But since you intend to remove the FK where will the model document which user belongs to which tenancy?

Dan's reply:

Our proposal is somewhat influenced by our existing legacy that ApplicationUser already has an atPath; in suggestion its value be treated like a regex, it is in a sense acting like a vector rather than a scalar.

An alternative approach would be to simply make the ApplicationUser <-> ApplicationTenancy into a many-to-many association rather than many-to-one. This tuple entity could be application-specific, it doesn't need to live in the security module. (You would probably then hide the ApplicationUser#atPath using a subscriber because it wouldn't have any meaning if you also had this tuple).

From what I understand this is something that be will be evaluated at runtime suing atPath, but how will I enable non-technical users to manage this association? From the runtime perspective I feel using regex to eval whether a user belongs to a tenancy is fine, but from a modelling / user-user perspective I'm not sure I understood how this should work?

Dan's reply:

At least for our use case, setting up app tenancies for end-users tends to be programmatic or is done by an administrator, so this isn't really a problem for us. There's nothing to prevent you from writing a mixin on ApplicationUser that could provide a better UI for non-administrators. This mixin could, for example, populate an application-specific tuple between ApplicatoinUser and ApplicationTenancy. You could then use a custom impl of the ApplicationTenancyEvaluator [1] to query this tuple in determining if a user had access.

@danhaywood danhaywood closed this in 69d7e0e Dec 5, 2016

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment