# actix_web::State - Rust
API documentation for the Rust `State` struct in crate `actix_web`.
Keywords: rust, rustlang, rust-lang, State

# Struct actix_web::State [−] [src]

    pub struct State<S>(_);

Access an application state

`S` - application state type

## Example

    #[macro_use] extern crate serde_derive;
    use actix_web::{http, App, Path, State};

    /// Application state
    struct MyApp {
        msg: &'static str,
    }

    #[derive(Deserialize)]
    struct Info {
        username: String,
    }

    /// extract path info using serde
    fn index(data: (State<MyApp>, Path<Info>)) -> String {
        let (state, path) = data;
        format!("{} {}!", state.msg, path.username)
    }

    fn main() {
        let app = App::with_state(MyApp { msg: "Welcome" }).resource(
            "/{username}/index.html", // <- define path parameters
            |r| r.method(http::Method::GET).with(index),
        ); // <- use `with` extractor
    }

## Trait Implementations

###

`impl<S> Deref for State<S>`

[src]

#### `type Target = S`

The resulting type after dereferencing.

####
ⓘImportant traits for &'a mut R

### Important traits for &'a mut R

`impl<'a, R> Read for &'a mut R where
R: Read + ?Sized, impl<'a, W> Write for &'a mut W where
W: Write + ?Sized, impl<'a, I> Iterator for &'a mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;`

`fn deref(&self) -> &S`

[src]

Dereferences the value.

###

`impl<S> FromRequest<S> for State<S>`

[src]

#### `type Config = ()`

Configuration for conversion process

#### `type Result = State<S>`

Future that resolves to a Self

####

`fn from_request(req: &HttpRequest<S>, _: &Self::Config) -> Self::Result`

[src]

Convert request to a Self

####

`fn extract(req: &HttpRequest<S>) -> Self::Result`

[src]

Convert request to a Self Read more

## Auto Trait Implementations

###

`impl<S> !Send for State<S>`

###

`impl<S> !Sync for State<S>`

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