Trait actix_web::FromRequest[−][src]

pub trait FromRequest: Sized {
    type Config: Default + 'static;
    type Error: Into<Error>;
    type Future: Future<Output = Result<Self, Self::Error>>;
    fn from_request(req: &HttpRequest, payload: &mut Payload) -> Self::Future;

    fn extract(req: &HttpRequest) -> Self::Future { ... }

    fn configure<F>(f: F) -> Self::Config
    where
        F: FnOnce(Self::Config) -> Self::Config,
    { ... }
}
Expand description

Trait implemented by types that can be extracted from request.

Types that implement this trait can be used with Route handlers.

Associated Types

Configuration for this extractor.

The associated error which can be returned.

Future that resolves to a Self.

Required methods

Create a Self from request parts asynchronously.

Provided methods

Create a Self from request head asynchronously.

This method is short for T::from_request(req, &mut Payload::None).

Create and configure config instance.

Implementations on Foreign Types

Optionally extract a field from the request

If the FromRequest for T fails, return None rather than returning an error response

Examples

use actix_web::{web, dev, App, Error, HttpRequest, FromRequest};
use actix_web::error::ErrorBadRequest;
use futures_util::future::{ok, err, Ready};
use serde::Deserialize;
use rand;

#[derive(Debug, Deserialize)]
struct Thing {
    name: String
}

impl FromRequest for Thing {
    type Error = Error;
    type Future = Ready<Result<Self, Self::Error>>;
    type Config = ();

    fn from_request(req: &HttpRequest, payload: &mut dev::Payload) -> Self::Future {
        if rand::random() {
            ok(Thing { name: "thingy".into() })
        } else {
            err(ErrorBadRequest("no luck"))
        }

    }
}

/// extract `Thing` from request
async fn index(supplied_thing: Option<Thing>) -> String {
    match supplied_thing {
        // Puns not intended
        Some(thing) => format!("Got something: {:?}", thing),
        None => format!("No thing!")
    }
}

fn main() {
    let app = App::new().service(
        web::resource("/users/:first").route(
            web::post().to(index))
    );
}

Optionally extract a field from the request or extract the Error if unsuccessful

If the FromRequest for T fails, inject Err into handler rather than returning an error response

Examples

use actix_web::{web, dev, App, Result, Error, HttpRequest, FromRequest};
use actix_web::error::ErrorBadRequest;
use futures_util::future::{ok, err, Ready};
use serde::Deserialize;
use rand;

#[derive(Debug, Deserialize)]
struct Thing {
    name: String
}

impl FromRequest for Thing {
    type Error = Error;
    type Future = Ready<Result<Thing, Error>>;
    type Config = ();

    fn from_request(req: &HttpRequest, payload: &mut dev::Payload) -> Self::Future {
        if rand::random() {
            ok(Thing { name: "thingy".into() })
        } else {
            err(ErrorBadRequest("no luck"))
        }
    }
}

/// extract `Thing` from request
async fn index(supplied_thing: Result<Thing>) -> String {
    match supplied_thing {
        Ok(thing) => format!("Got thing: {:?}", thing),
        Err(e) => format!("Error extracting thing: {}", e)
    }
}

fn main() {
    let app = App::new().service(
        web::resource("/users/:first").route(web::post().to(index))
    );
}

Extract text information from a request’s body.

Text extractor automatically decode body according to the request’s charset.

PayloadConfig allows to configure extraction process.

Examples

use actix_web::{post, web, FromRequest};

// extract text data from request
#[post("/")]
async fn index(text: String) -> String {
    format!("Body {}!", text)
}

Implementors

Extract the request’s method.

Examples

use actix_web::{http::Method, web, App, Responder};

async fn handler(method: Method) -> impl Responder {
    format!("Request method: {}", method)
}

let app = App::new().default_service(web::to(handler));

Extract the request’s URI.

Examples

use actix_web::{http::Uri, web, App, Responder};

async fn handler(uri: Uri) -> impl Responder {
    format!("Requested path: {}", uri.path())
}

let app = App::new().default_service(web::to(handler));

Extract binary data from a request’s payload.

Collects request payload stream into a Bytes instance.

Use PayloadConfig to configure extraction process.

Examples

use actix_web::{post, web};

/// extract binary data from request
#[post("/")]
async fn index(body: web::Bytes) -> String {
    format!("Body {:?}!", body)
}

It is possible to get HttpRequest as an extractor handler parameter

Examples

use actix_web::{web, App, HttpRequest};
use serde::Deserialize;

/// extract `Thing` from request
async fn index(req: HttpRequest) -> String {
   format!("Got thing: {:?}", req)
}

fn main() {
    let app = App::new().service(
        web::resource("/users/{first}").route(
            web::get().to(index))
    );
}

See here for example of usage as an extractor.

See here for example of usage as an extractor.

See here for example of usage as an extractor.

See here for example of usage as an extractor.

See here for example of usage as an extractor.

See here for example of usage as an extractor.