Add way to case-sensitive string filtering

[LukasKalbertodt]

Equality filters on strings work case-insensitively. This is useful for many cases, but case-sensitive matching is important as well. The docs even mention a use case:

Filters have several use-cases, such as restricting the results a specific user has access to [...]

That's also the case for us. Specifically, each item in the index has a list of roles attached to it (a string array). Each user also has a list of roles. A specific user can view a specific item iff at least one of the user's role is inside the item's roles. This can almost be implemented with Meili, if it weren't for the case insensitive check. Roles must certainly be checked case sensitively.

Possible workarounds: doing the filtering in our backend after receiving all results OR encoding the roles somehow, e.g. as hex string. Both options are obviously not great.

So yeah, it would be really great if Meili could filter case sensitively!

[gmourier]

Hi @LukasKalbertodt 👋

Why case sensitivity is critical here?

Thanks

[LukasKalbertodt]

Well, the reason is simply that our role system works like that: roles are opaque, case-sensitive strings. foo and Foo are semantically different roles and a user with the role Foo is not allowed to see an item with role foo.

I think the "don't interpret those strings, just treat them as opaque data" is not too uncommon of a requirement. You could also imagine some base64 encoded binary data in strings. And for base64, lowercase and uppercase letters are obviously different and case-insensitive comparison don't make sense here.

[gmourier]

Thanks, @LukasKalbertodt for this precision.

One idea: It could be a new setting permitting to set some attributes to be case-sensitive since case-insensitivity seems to work well for most of our users.

I leave this discussion open to gather more feedback on this and see later if it is to be prioritized.

[gmourier]

Hey @LukasKalbertodt 👋

I'm locking that discussion in favor of #555

Thank you!