Cache invalidation on POST, PATCH, DELETE

[SirRawlins]

Hello Folks,

I was looking for any previous discussion around invalidating the cache when making POST, PATCH and DELETE requests so that the data is synced on the next GET request.

Is there any particular reason that this hasn't been included as behaviour within the Caching middleware?

[iMacTia]

Hi @SirRawlins,

I don't think there'a any particular reason for this, except for the fact that not everyone have clear in mind how a RESTful API should work (or they simply don't want to have it).
In fact, your question makes perfectly sense in the context of a RESTful API, but can bring to unexpected results outside of it.
I joined recently so I can't really speak for the author of the middleware, but I think he chose to leave the decision to invalidate the requests more open to avoid this kind of issues.
This way, you can always manually delete the cache to have the correct behaviour.
Making it the standard behaviour, instead, could lead to performance issues (again, just in case the API you're calling is not RESTful).

I understand and appreciate your thoughts, and I think the best course of action in this case is to have a config option for the middleware to enable the behaviour you described.
This will allow to:

• Opt-in if you desire this behaviour
• Make it the standard behaviour on a later major release (after a couple of releases with a deprecation warning)

Happy to review a PR if you want to work on it :)

Thanks!

[SirRawlins]

@iMacTia thanks for the insight. I've actually been playing around with my own option at the moment which is a separate middleware, it forwards all GET requests down to the standard Cache middleware, or for PUT/PATCH/DELETE requests invalidates the cache using the key from the standard cache middleware.

Still plenty of work to be done to make it configurable, or for it to use the HTTP Cache headers but we're making progress.

Once I have something semi-viable I'll try and wrap it up into a PR.

[iMacTia]

@SirRawlins sounds great!

Please do take your time and share it with the community when you feel comfortable with it 😊

[lucasmazza]

Still plenty of work to be done to make it configurable, or for it to use the HTTP Cache headers but we're making progress.

You might want to take a look into https://github.com/plataformatec/faraday-http-cache (I'm the author of the project).