pub struct Context<S = ()> {
    pub req: Request,
    pub resp: Response,
    pub exec: Executor,
    pub remote_addr: SocketAddr,
    /* private fields */
}
Expand description

A structure to share request, response and other data between middlewares.

Example

use roa_core::{App, Context, Next, Result};
use tracing::info;
use tokio::fs::File;

let app = App::new().gate(gate).end(end);
async fn gate(ctx: &mut Context, next: Next<'_>) -> Result {
    info!("{} {}", ctx.method(), ctx.uri());
    next.await
}

async fn end(ctx: &mut Context) -> Result {
    ctx.resp.write_reader(File::open("assets/welcome.html").await?);
    Ok(())
}

Fields

req: Request

The request, to read http method, uri, version, headers and body.

resp: Response

The response, to set http status, version, headers and body.

exec: Executor

The executor, to spawn futures or blocking works.

remote_addr: SocketAddr

Socket addr of last client or proxy.

Implementations

Clone URI.

Example
use roa_core::{App, Context, Result};

let app = App::new().end(get);

async fn get(ctx: &mut Context) -> Result {
    assert_eq!("/", ctx.uri().to_string());
    Ok(())
}

Clone request::method.

Example
use roa_core::{App, Context, Result};
use roa_core::http::Method;

let app = App::new().end(get);

async fn get(ctx: &mut Context) -> Result {
    assert_eq!(Method::GET, ctx.method());
    Ok(())
}

Search for a header value and try to get its string reference.

Example
use roa_core::{App, Context, Result};
use roa_core::http::header::CONTENT_TYPE;

let app = App::new().end(get);

async fn get(ctx: &mut Context) -> Result {
    assert_eq!(
        Some("text/plain"),
        ctx.get(CONTENT_TYPE),
    );
    Ok(())
}

Search for a header value and get its string reference.

Otherwise return a 400 BAD REQUEST.

Example
use roa_core::{App, Context, Result};
use roa_core::http::header::CONTENT_TYPE;

let app = App::new().end(get);

async fn get(ctx: &mut Context) -> Result {
    assert_eq!(
        "text/plain",
        ctx.must_get(CONTENT_TYPE)?,
    );
    Ok(())
}

Clone response::status.

Example
use roa_core::{App, Context, Result};
use roa_core::http::StatusCode;

let app = App::new().end(get);

async fn get(ctx: &mut Context) -> Result {
    assert_eq!(StatusCode::OK, ctx.status());
    Ok(())
}

Clone request::version.

Example
use roa_core::{App, Context, Result};
use roa_core::http::Version;

let app = App::new().end(get);

async fn get(ctx: &mut Context) -> Result {
    assert_eq!(Version::HTTP_11, ctx.version());
    Ok(())
}

Store key-value pair in specific scope.

Example
use roa_core::{App, Context, Result, Next};

struct Scope;
struct AnotherScope;

async fn gate(ctx: &mut Context, next: Next<'_>) -> Result {
    ctx.store_scoped(Scope, "id", "1".to_string());
    next.await
}

async fn end(ctx: &mut Context) -> Result {
    assert_eq!(1, ctx.load_scoped::<Scope, String>("id").unwrap().parse::<i32>()?);
    assert!(ctx.load_scoped::<AnotherScope, String>("id").is_none());
    Ok(())
}

let app = App::new().gate(gate).end(end);

Store key-value pair in public scope.

Example
use roa_core::{App, Context, Result, Next};

async fn gate(ctx: &mut Context, next: Next<'_>) -> Result {
    ctx.store("id", "1".to_string());
    next.await
}

async fn end(ctx: &mut Context) -> Result {
    assert_eq!(1, ctx.load::<String>("id").unwrap().parse::<i32>()?);
    Ok(())
}

let app = App::new().gate(gate).end(end);

Search for value by key in specific scope.

Example
use roa_core::{App, Context, Result, Next};

struct Scope;

async fn gate(ctx: &mut Context, next: Next<'_>) -> Result {
    ctx.store_scoped(Scope, "id", "1".to_owned());
    next.await
}

async fn end(ctx: &mut Context) -> Result {
    assert_eq!(1, ctx.load_scoped::<Scope, String>("id").unwrap().parse::<i32>()?);
    Ok(())
}

let app = App::new().gate(gate).end(end);

Search for value by key in public scope.

Example
use roa_core::{App, Context, Result, Next};

async fn gate(ctx: &mut Context, next: Next<'_>) -> Result {
    ctx.store("id", "1".to_string());
    next.await
}

async fn end(ctx: &mut Context) -> Result {
    assert_eq!(1, ctx.load::<String>("id").unwrap().parse::<i32>()?);
    Ok(())
}

let app = App::new().gate(gate).end(end);

Trait Implementations

Returns a copy of the value. Read more

Performs copy-assignment from source. Read more

The resulting type after dereferencing.

Dereferences the value.

Mutably dereferences the value.

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more

Immutably borrows from an owned value. Read more

Mutably borrows from an owned value. Read more

Performs the conversion.

Instruments this type with the provided Span, returning an Instrumented wrapper. Read more

Instruments this type with the current Span, returning an Instrumented wrapper. Read more

Performs the conversion.

The resulting type after obtaining ownership.

Creates owned data from borrowed data, usually by cloning. Read more

🔬 This is a nightly-only experimental API. (toowned_clone_into)

Uses borrowed data to replace owned data, usually by cloning. Read more

The type returned in the event of a conversion error.

Performs the conversion.

The type returned in the event of a conversion error.

Performs the conversion.

Attaches the provided Subscriber to this type, returning a WithDispatch wrapper. Read more

Attaches the current default Subscriber to this type, returning a WithDispatch wrapper. Read more