Inject dependency into a filter using openapi macro

[seguidor777]

Hello,

I'm using the openapi feature and trying to pass the database service to the filter, is this possible?
I need to implement a custom filter to compare the header content against the database records.

This is the code I have:

fn authenticate(db_service: DbService,) -> impl Clone + Filter<Extract = (), Error = Rejection> {
    let token = rweb::header::<String>("authorization");

    db_service.verify_token(&token);
    // TODO: Return filter
}

#[get("/products")]
#[openapi(id = "products.get")]
#[openapi(summary = "List products")]
#[openapi(response(code = "200", description = "OK"))]
pub fn list_products(
    #[data] db_service: DbService,
    #[filter = "authenticate(db_service)"] _header: (),
) -> Json<Vec<Product>> {
    Json::from(db_service.list_products().unwrap())
}

When I run this code it returns the following error:

error: custom attribute panicked
  --> src/api/products.rs:33:1
   |
33 | #[get("/products")]
   | ^^^^^^^^^^^^^^^^^^
   |
   = help: message: unexpected token

[seguidor777]

After digging into the source code a bit, I found that the filters don't take any parameters.
I think I should first add a filter to extract the header from the token, then I would need to call the authenticate function from the handler function. Something like this

fn token_header() -> impl Clone + Filter<Extract = (String,), Error = Rejection> {
    rweb::header::<String>("authorization")
}

#[get("/products")]
#[openapi(id = "products.get")]
#[openapi(summary = "List products")]
#[openapi(response(code = "200", description = "OK"))]
#[openapi(response(code = "401", description = "Unauthorized"))]
pub fn list_products(
    #[data] db_service: DbService,
    #[filter = "token_header"] token: String,
) -> Json<Vec<Product>> {
    **// Call to authenticate(db_service, token)**
    Json::from(db_service.list_products().unwrap())
}

However, I would like to call the authenticate method from a filter and be able to reuse it in the other handlers.
I think it's important to be able to add filters using with as in this example seanmonstar/warp#62 (comment)

[kdy1]

See

rweb/tests/router.rs

Lines 48 to 49 in 624d66e

	#[get("/use")]
	fn use_db(#[data] _db: Db) -> String {

[E-gy]

@kdy1 afaiu The question is about using #[data] in a filter, or rather in general passing [custom] arguments to filters.

// This is a filter that takes a custom argument
fn authenticate(db_service: DbService,) -> impl Clone + Filter<Extract = (), Error = Rejection> {
    let token = rweb::header::<String>("authorization");

    db_service.verify_token(&token);
    // TODO: Return filter
}

#[get("/products")]
pub fn list_products(
    #[data] db_service: DbService,
    // Here we (attempt to) use the `authenticate` filter, with the `db_service` argument received from data
    #[filter = "authenticate(db_service)"] _header: (),
) -> Json<Vec<Product>> {
    Json::from(db_service.list_products().unwrap())
}

[seguidor777]

In fact, I am looking for filters where we can inject any kind of dependencies and do some middleware tasks like logging, tracing, authentication and authorization. I know this is possible with the normal handlers, but I have not seen how to do it through the openapi macros

In this tutorial there is an example of a filter which receives three dependencies, I'm trying to achieve the same with openapi
https://github.com/zupzup/rust-casbin-example/blob/main/src/main.rs#L53

[szagi3891]

What if you build a function that returns a function ? That is, you could potentially make a function that receives dependencies and returns a function.

But the problem will remain, because it will not be possible to inject this filter using a macro :/

[seguidor777]

Yea and I think using the macro is essential because makes the code more ergonomic