bug: injected dependency is not available in filter functions.

[hsblhsn]

Hello, dependency injection is a good feature and I have followed this tutorial to implement mine.

• The issue is present in the latest release.
• I have searched the issues of this repository and believe that this is not a duplicate.

Current Behavior 😯

Currently, my dependencies are available inside the hook functions and in every mutation like ent.UserMutation. But I can't access them inside the filter function or type. They are not available in ent.UserFilter.

Expected Behavior 🤔

I expect the injected dependencies to be available all over my ent packages wherever I can touch.

Your Environment 🌎

Tech	Version
Go	1.17.5
Ent	0.10.x
Database	Postgresql
Driver	pgx

[crossworth]

Hello @hsblhsn, could you create a simple example using https://github.com/ent/bug?

[yonidavidson]

Hi @hsblhsn , which filters function do you mean?
Can you give me an example?
For example

c.User.Query().Where(user.NameEQ("yoni")).OnlyX(ctx)

Where are you expecting to get access to the Dependency?

[hsblhsn]

Suppose I have pet and user microservice.

And I have a api client to check if the user has access to the pet.

so in a privacy filter function, I would use it like.

pets := m.APIClient.GetAllPets(ctx)
filter.Where(user.HasPetsIn(pets))

I have injected APIClient using entc.Dependency options as shown here at https://entgo.io/blog/2021/11/1/sync-to-external-data-systems-using-hooks

The problem is I can't access APIClient from FilterFuncs but I can easily access them using them in hooks. I want to access it in FilterFuncs as well.

Thank you!

[yonidavidson]

Why not add your API Client to the context (where you add the pet name)?

[hsblhsn]

Nice idea! Thanks for that. But still, it would be nice for a dependency to be accessible from FilterFuncs. Because that's the whole point of creating a dependency at entity level.

[yonidavidson]

I think the reason is to avoid security issues by allowing the privacy layer to access the data it's protecting.
@a8m is this the reason?

[a8m]

No real reason, the Depdendecy option was added after privacy. However, I just landed #2473 to inject the config object (with all its dependencies) to the typed filters. See example -

ent/entc/integration/privacy/rule/rule.go

Lines 111 to 121 in 4cf6dd7

	func FilterUsesDep() privacy.QueryRule {
	return privacy.FilterFunc(func(ctx context.Context, f privacy.Filter) error {
	u, ok := f.(*ent.UserFilter)
	if !ok {
	return privacy.Denyf("unexpected filter type %T", f)
	}
	// Access the dependency after the type is resolved.
	_ = u.HTTPClient
	return privacy.Skip
	})
	}

@hsblhsn, I wonder how you use the Filter functions. Because the current privacy.Filter is an interface and dependencies are injected as fields. So currently, there's no way to access them without type-assertion.

Do you use generic Filters that are applied on multiple types or type-assertion is good enough for you? Thanks