Display Different Page Notices Based on User Role

[Scott-James-Hurley]

Motivation

The Central Laser Facility (CLF) has started using the proposals software and they need to be able to post CLF-specific notices for their users. Currently, there is no way to change the notice displayed to a user on a particular page based on any characteristic. The ISIS development team suggests extending the Page Editor functionality to allow User Officers to create notices based on tags. If a user is signed in as a derived role with that tag (currently assuming one tag per role), they will see the notice created for that tag on the page they are on. Relevant issue

Proof of Concept

Please see the below screenshots of a proof of concept for the page editor:

Technique proposal page notice for base roles Technique proposal page notice for derived roles with the `ISIS` tag

This will require changing the pagetext table to also reference tag id for finding the correct content.

The code for the proof of concept is here. This POC only covers creating page notices, not displaying the correct one for derived roles. The dropdown menu for selecting a tag is hardcoded just for demonstration purposes.

SQL

The following is the SQL required for the proof of concept:

ALTER TABLE pagetext
  ADD COLUMN page_id integer,
  ADD COLUMN tag_id integer REFERENCES tag (tag_id) ON UPDATE CASCADE ON DELETE CASCADE;

UPDATE pagetext SET page_id = pagetext_id;

ALTER TABLE pagetext
  ADD CONSTRAINT page_id_not_null NOT NULL page_id,
  ADD CONSTRAINT unique_tag_pages UNIQUE (page_id, tag_id);

INSERT INTO tag
VALUES (1, 'ISIS', 'ISIS'),
       (2, 'CLF', 'CLF');

What are people's thoughts?

[simonfernandes]

I like this idea. To extend on your design slightly, would it be worth considering a model based on overrides that also includes roles for future flexibility?

A made up scenario might be that we want to show different help page text (currently accessible to all roles) based on both role and tag so that we can show people specific documentation for their role and facility.

In the UI, very similarly to what you have now, the "Base Role" might become "Default", where you're editing the default page text unless you select an override for a specific role/tag combination to modify.

The database might have a separate pagetext_override table that references the role as well as page text and tag, and has the replacement content. The existing pagetext could act as the default, with an override being used when there's a matching role/tag combination.

[Scott-James-Hurley]

Fetching the default page text for the user when there's no override found is a great idea. Has displaying different content for roles been requested by users before? I'm hoping to talk to EG about this so I can raise it then.

[simonfernandes]

I don't think we've had anything requested and the use case is probably quite limited, so it may well not be worth the added complexity of implementing at this stage. Mainly mentioning it in case it's a plausible future requirement for someone that we may want to factor into the design now.

[Scott-James-Hurley]

Makes sense to do now. If other facilities could please say if this is something they'd want, I'd appreciate it.

[jekabs-karklins]

I think this is a solid plan,

One question i'm unceratain about is

ALTER TABLE pagetext
  ADD COLUMN page_id integer, <== Why do we need page id we already have `pagetext_id`
  ADD COLUMN tag_id integer REFERENCES tag (tag_id) ON UPDATE CASCADE ON DELETE CASCADE; <== should this reference the role instead of tag? I'm thinking user might have multiple tags, and then how do you determine the precidence, while user has only one current rolde.

[Scott-James-Hurley]

pagetext_id is the table's new primary key and page_id is used to identify the page the notice is for e.g. HELP or XPRESS PROPOSALS. Role id could be used instead of tags, I'll make those changes.