Event-based STOMP header generation

[adam-vessey]

JIRA Ticket: N/A

• Other Relevant Links (Google Groups discussion, related pull requests, Release pull requests, etc.)

Fixes Islandora/documentation#1856

What does this Pull Request do?

Introduces an event-based mechanism to generate headers for STOMP messages, so other modules can subscribe to the event to influence what headers are set.

What's new?

We dispatch a new StompHeaderEvent (islandora.stomp.header_event) event, which can be subscribed to in other modules in order to add/alter the headers which get used for the STOMP message.

There's a base subscriber for this new event included with a very low priority which maintains the current behaviour of generating and adding the token, but it has been made to avoid overwriting an Authorization token, if there's already one set.

One divergence is the addition of the aud claim; however, the implementation has allowed JWTs without this claim to continue being accepted, expecting that we will remove this ability in the future.

May be a small PR in the future making use of this to address Islandora/documentation#1857

How should this be tested?

Pretty much just regression test, creating some content with derivatives, and ensure that:

• The derivatives are created
• Things are indexed as expected
• Things are deleted from the index accordingly.

Additional Notes:

Any additional information that you think would be helpful when reviewing this PR.

Example:

• Does this change the interface, add a new feature, or otherwise change behaviours that would require updating documentation? No?
• Does this change add any new dependencies? No.
• Does this change require any other modifications to be made to the repository (ie. Regeneration activity, etc.)? No.
• Could this change impact execution of existing code? Unlikely.

Interested parties

@Islandora/8-x-committers

[whikloj]

This works fine for content nodes, but adding media is failing.

[whikloj]

StreamWrapperManager is still used on line 109/53, I tried to add an audio media and got a WSOD.

Stacktrace in the apache log refers to

... Error: Class 'Drupal\\islandora\\Plugin\\Action\\StreamWrapperManager' not found in /home/vagrant/all_claw/islandora/src/Plugin/Action/EmitFileEvent.php ...

[adam-vessey]

Ah... stuff was originally developed against (a fork of) 1.1.1... which was still using the (now deprecated) $fileSystem->uriScheme() thing... patch applied relatively cleanly (IIRC), and the actions were giving a checkmark... I guess this class isn't actually covered under any (unit) tests?

Anyway... the $fileSystem being injected here is no longer being used. Should we drop it? Would rather simplify the class. Removal should be inline with Drupal's policies WRT protected properties?:

Protected properties on a class are always considered @internal unless they're on a base class marked with @api

[whikloj]

Probably no test, if you want to add a unit test that would be 🥇 . As for the $fileSystem, you are correct that it does appear to not be necessary, I'd vote to get rid of it and simplify.

[adam-vessey]

Rebased on top of HEAD, and added the reference here back in... left $fileSystem (for now?).

[adam-vessey]

Did take a look at how tests might be written for this ::generateData() stuff; however, the method is protected... would get into either changing the visibility (and pushing such a change up into the interface and propagating around), using reflection to adjust the visibility when running the test (which is relatively simple but gross) or mocking/loading up all the services required to ::execute() the event, which... is... rather more complex.

... start wondering if things should be structured differently, to facilitate testing?... anyway...

[whikloj]

👍