'Actix-Web reports "App data is not configured" when processing a file upload

I'm using the Actix framework to create a simple server and I've implemented a file upload using a simple HTML frontend.

use actix_web::web::Data;
use actix_web::{middleware, web, App, HttpResponse, HttpServer};
use std::cell::Cell;

// file upload functions, the same as you can find it under the 
// actix web documentation:
// https://github.com/actix/examples/blob/master/multipart/src/main.rs :
mod upload; 


fn index() -> HttpResponse {
    let html = r#"<html>
            <head><title>Upload Test</title></head>
            <body>
                <form target="/" method="post" enctype="multipart/form-data">
                    <input type="file" name="file"/>
                    <input type="submit" value="Submit"></button>
                </form>
            </body>
        </html>"#;

    HttpResponse::Ok().body(html)
}

#[derive(Clone)]
pub struct AppState {        
    counter: Cell<usize>,        
}

impl AppState {
    fn new() -> Result<Self, Error> {
        // some stuff
        Ok(AppState {
            counter: Cell::new(0usize),
        })
    }
}
fn main() {

    let app_state = AppState::new().unwrap();

    println!("Started http server: http://127.0.0.1:8000");

    HttpServer::new(move || {
        App::new()
            .wrap(middleware::Logger::default())
            .service(
                web::resource("/")
                    .route(web::get().to(index))
                    .route(web::post().to_async(upload::upload)),
            )
            .data(app_state.clone())
    })
    .bind("127.0.0.1:8000")
    .unwrap()
    .run()
    .unwrap();
}

Running the server works fine, but when I submit the file upload, it says:

App data is not configured, to configure use App::data()

I don't know what to do.

Solution 1:^[1]

I asked people in the rust-jp community to tell you the correct answer.

Use Arc outer HttpServer.

/*
~~~Cargo.toml
[package]
name = "actix-data-example"
version = "0.1.0"
authors = ["ncaq <[email protected]>"]
edition = "2018"

[dependencies]
actix-web = "1.0.0-rc"
env_logger = "0.6.0"
~~~
 */

use actix_web::*;
use std::sync::*;

fn main() -> std::io::Result<()> {
    std::env::set_var("RUST_LOG", "actix_web=trace");
    env_logger::init();

    let data = Arc::new(Mutex::new(ActixData::default()));
    HttpServer::new(move || {
        App::new()
            .wrap(middleware::Logger::default())
            .data(data.clone())
            .service(web::resource("/index/").route(web::get().to(index)))
            .service(web::resource("/create/").route(web::get().to(create)))
    })
    .bind("0.0.0.0:3000")?
    .run()
}

fn index(actix_data: web::Data<Arc<Mutex<ActixData>>>) -> HttpResponse {
    println!("actix_data: {:?}", actix_data);
    HttpResponse::Ok().body(format!("{:?}", actix_data))
}

fn create(actix_data: web::Data<Arc<Mutex<ActixData>>>) -> HttpResponse {
    println!("actix_data: {:?}", actix_data);
    actix_data.lock().unwrap().counter += 1;
    HttpResponse::Ok().body(format!("{:?}", actix_data))
}

/// actix-web???????
#[derive(Debug, Default)]
struct ActixData {
    counter: usize,
}

This post report to upstream. Official document data cause App data is not configured, to configure use App::data() · Issue #874 · actix/actix-web

Solution 2:^[2]

Faced a similar error: Internal Server Error: "App data is not configured, to configure use App::data()"

from: https://github.com/actix/examples/blob/master/state/src/main.rs

For global shared state, we wrap our state in a actix_web::web::Data and move it into the factory closure. The closure is called once-per-thread, and we clone our state and attach to each instance of the App with .app_data(state.clone()).

Thus:

impl AppState {
    fn new() -> actix_web::web::Data<AppState> {
        actix_web::web::Data<AppState> {
            counter: Cell::new(0usize),
        }
    }
}

...and in factory closure:

... skip ...
HttpServer::new(move || {
    App::new()
        .app_data(AppState::new().clone())
... skip ...

For thread-local state, we construct our state within the factory closure and attach to the app with .data(state).

Thus:

... skip ...
HttpServer::new(move || {
    let app_state = Cell::new(0usize);
    App::new()
        .data(app_state)
... skip ...

Solution 3:^[3]

Instead of:

App::data(app_state.clone())

You should use:

App::app_data(app_state.clone())

Solution 4:^[4]

If you call a function that has any parameter which doesn't match the HttpServer app data it will give you the same error.

For example, in this case, the &Client needed to be a Client.

pub fn index(client: web::Data<&Client>() {
// ...

}

Solution 5:^[5]

You have to register your data before you can use it:

App::new().data(AppState::new())

Sources

This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.

Source: Stack Overflow

Solution	Source
Solution 1	ncaq
Solution 2	Belanchuk
Solution 3	Milan
Solution 4	Mr. Brad
Solution 5	Shepmaster

'Actix-Web reports "App data is not configured" when processing a file upload

Solution 1:[1]

Solution 2:[2]

Solution 3:[3]

Solution 4:[4]

Solution 5:[5]