Add a possibility to delete all reselect selectors stored in the cache under a specific key pattern

[drgarlic]

Hi,

I have a problem with the way we can remove selectors from a cache object.

For example, in my code, the keys under which my selectors are stored, are generated using a function and are following a specific pattern (number(:number)*). I would like to remove from the cache every selector stored under a key starting with a "1".
The problem is, that I cannot use selector.getMatchingSelector because it uses the resolver instead of directly checking if _cache has a selector stored under a specific string.

I found a way to counter that by adding this function to the createCachedSelector function:

selector.getCache = () => {
      return cache._cache;
};

and by removing manually in my code every selector stored under a key starting with a "1".
But it would be much cleaner if something similar was implemented directly in your cache objects.

So my question is the next, would it be possible to add a function which removes all the selectors of a cache object that are stored under a specific key pattern ?
If not, could you at least add a function to createCachedSelector which allows us to get the _cache of a cache object (like the one I had to add).

Feel free to let me know, if I'm not being clear enough !

[toomuchdesign]

Hi @gawlk !
I think selector methods should interact with the cache by providing selector arguments but not directly the resulting cacheKey. For this reason I wouldn't add any other special method to interact with the cache but I'd go for directly exposing the cache object.

It could be a viable option for a next release.

We might consider to expose a getter as you suggest or simply expose the cache object as a property:

selector.getCache();  // as getter
selector.cache;       // as property

In the meanwhile there is another solution to let you not use a patched version of re-reselect.

From version 1 you can provide a custom cacheObject on selector initialization. Therefore you could:

1. extend one of the provided cacheObjects with the special cache clearing method:

import {FlatObjectCache} from 're-reselect';

export class CustomFlatObjectCache extends FlatObjectCache {
  superCacheDeletion() {
    //...
  }
}

2. provide it as a custom cache object keeping a reference pointing to it for later use.

import createCachedSelector from 're-reselect';
import CustomFlatObjectCache from './CustomFlatObjectCache';

const myCacheObjectInstance = new CustomFlatObjectCache();
const mySelector = createCachedSelector(
  // ...
)(
  resolverFunction,
  {
    cacheObject: myCacheObjectInstance,
  }
);

3. call the custom cacheObject method whenever you want

myCacheObjectInstance.superCacheDeletion('foo');

Could it work in your use case?

Greetings!

[drgarlic]

That's great, both exposing a getter or the cache object as a property would work for me !
Any idea when the next release will be out ?

I'll your try your temporary solution and I'll let you know ! But from the looks of it, it should work.

Thank you very much !

EDIT: It works ! Should I close the issue or wait until you release the next version (with the getter) ?

[toomuchdesign]

Glad to hear that!
Let's keep this ticket open until the new release.

Greetings!

[toomuchdesign]

Shipped! v2.1.0 🎉