Alternative storage mechanisms for cache

[AlecAivazis]

At the moment, the only storage mechanism supported by the cache holds onto everything in memory. Houdini should provide an out of the box solution for indexdb or local storage so users can decide what's best for their application. The user should also be able to pass a custom solution through the config file.

[frederikhors]

This is blocking for us. Example: I open the web app and navigate. I close the app. I re-open it after a few minutes and now there is no internet. I should still see the (old, maybe stale) data. Right now I see nothing but loading spinners!

Urql uses IndexedDB (for the "async" non-blocking behavior), but we can also start with LocalStorage. I think this is really simple to do but I don't know the Houdini code and I don't have time right now to investigate further.

Such a pity, a new project is starting right now and I think we'll stick with urql because of this!

[frederikhors]

@AlecAivazis @jycouet is there any ETA for this? Just to start, also with LocalStorage only.

Houdini is just too good to go back to using anything else.

[jycouet]

In urql, they manage this with 'exchange', in Houdini, it would be with Client Plugin. It's supporting already a lot of use cases. Probably a few directions to explore and see if it's just using it or extending it a bit.

I don't have an ETA in mind, as it's a mix between time, usage, priority, effort, and willingness ^^

[frederikhors]

Thanks. May I ask what you use in your apps today? I assume you are using Houdini, but don't you need this? A hot cache that responds immediately and even if the browser is (temporarily) offline?

[jycouet]

I'm using it mainly for "Business Tools" where people are on a computer, connected to the internet 24/7.
That's why, I don't really have your use case on top of my list today.

But I definitely see the value of it in other scenarios:

• bad internet connexion / small drops
• very "static" content that doesn't need too much refresh (SSG some pages?)
• go away for 2 or 3 days, complete a task on a webapp, come back online and push updates (sync)

Where are you falling to? Or you have something else? 👀

[frederikhors]

This is especially useful if you're developing for web app used on phones...

[frederikhors]

What about something like: https://blog.kowalczyk.info/article/persisted-svelte-store-indexeddb.html and https://github.com/macfja/svelte-persistent-store?

[frederikhors]

https://github.com/macfja/svelte-persistent-store is amazing! Is the Houdini cache a Svelte Store yet?

[frederikhors]

This is the urql docs about: https://formidable.com/open-source/urql/docs/graphcache/offline/#custom-storages

[frederikhors]

@AlecAivazis, you haven't said a word about this, can I ask for your comment?

[AlecAivazis]

Hello! It's great to hear from you again 😍

Don't worry, my silence isn't because I don't care about this feature (quite the opposite). I just don't have much to say that jyc hasn't. As I'm sure you can imagine, maintaining Houdini take a LOT of work that has to be balanced against real life and personal needs/motivation. Unfortunately this means we have to split up our attention to ensure everything is attended to and I can't always respond to every thread.

Anyway, I agree this feature is important (its one of the oldest remaining features in the repo) but I just don't have the time to actually champion this through. One hurdle is that the svelte runtime currently has zero dependencies which I'd like to maintain. It shouldn't be too bad to overcome but definitely worth mentioning. If you have the time to dig into this, I would gladly offer any help you need, I dont think it would be that hard to pull off even if it was someone's first exposure to the caching logic