Struct puff_rs::web::server::Json

pub struct Json<T>(pub T);

JSON Extractor / Response.

When used as an extractor, it can deserialize request bodies into some type that implements serde::Deserialize. The request will be rejected (and a JsonRejection will be returned) if:

• The request doesn’t have a Content-Type: application/json (or similar) header.
• The body doesn’t contain syntactically valid JSON.
• The body contains syntactically valid JSON but it couldn’t be deserialized into the target type.
• Buffering the request body fails.

Since parsing JSON requires consuming the request body, the Json extractor must be last if there are multiple extractors in a handler. See “the order of extractors”

See JsonRejection for more details.

Extractor example

use axum::{
    extract,
    routing::post,
    Router,
};
use serde::Deserialize;

#[derive(Deserialize)]
struct CreateUser {
    email: String,
    password: String,
}

async fn create_user(extract::Json(payload): extract::Json<CreateUser>) {
    // payload is a `CreateUser`
}

let app = Router::new().route("/users", post(create_user));

When used as a response, it can serialize any type that implements serde::Serialize to JSON, and will automatically set Content-Type: application/json header.

Response example

use axum::{
    extract::Path,
    routing::get,
    Router,
    Json,
};
use serde::Serialize;
use uuid::Uuid;

#[derive(Serialize)]
struct User {
    id: Uuid,
    username: String,
}

async fn get_user(Path(user_id) : Path<Uuid>) -> Json<User> {
    let user = find_user(user_id).await;
    Json(user)
}

async fn find_user(user_id: Uuid) -> User {
    // ...
}

let app = Router::new().route("/users/:id", get(get_user));

Tuple Fields

0: T

Trait Implementations

impl<T> Clone for Json<T>where
    T: Clone,

fn clone(&self) -> Json<T>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T> Debug for Json<T>where
    T: Debug,

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl<T> Default for Json<T>where
    T: Default,

fn default() -> Json<T>

Returns the “default value” for a type.

impl<T> Deref for Json<T>

type Target = T

The resulting type after dereferencing.

fn deref(&self) -> &<Json<T> as Deref>::Target

Dereferences the value.

impl<T> DerefMut for Json<T>

fn deref_mut(&mut self) -> &mut <Json<T> as Deref>::Target

Mutably dereferences the value.

impl<T> From<T> for Json<T>

fn from(inner: T) -> Json<T>

Converts to this type from the input type.

impl<T, S, B> FromRequest<S, B, ViaRequest> for Json<T>where
    T: DeserializeOwned,
    B: 'static + Body + Send,
    <B as Body>::Data: Send,
    <B as Body>::Error: Into<Box<dyn Error + Send + Sync + 'static, Global>>,
    S: Send + Sync,

type Rejection = JsonRejection

If the extractor fails it’ll use this “rejection” type. A rejection is a kind of error that can be converted into a response.

fn from_request<'life0, 'async_trait>(
    req: Request<B>,
    state: &'life0 S
) -> Pin<Box<dyn Future<Output = Result<Json<T>, <Json<T> as FromRequest<S, B, ViaRequest>>::Rejection>> + Send + 'async_trait, Global>>where
    'life0: 'async_trait,
    Json<T>: 'async_trait,

Perform the extraction.

impl<T> IntoResponse for Json<T>where
    T: Serialize,

fn into_response(self) -> Response<UnsyncBoxBody<Bytes, Error>>

Create a response.

impl<T> Copy for Json<T>where
    T: Copy,