Nimble

A simple and elegant Rust web framework inspired by Express, built on Hyper.

Features

• Simple & Intuitive - Express-like route definition style
• Hyper-Powered - Built on a reliable HTTP library
• Zero-Cost Abstractions - Leverages Rust's powerful type system
• Type Safe - Compile-time guarantee of correct types for routes and handlers
• Practical Utilities - Built-in response types for JSON, HTML, file serving, redirects, etc.
• Automatic Static File Serving - Automatically mounts files from the ./static directory

Quick Start

Add the dependency to your Cargo.toml:

[dependencies]
nimble = { git = "https://github.com/yourusername/nimble" }
tokio = { version = "1", features = ["full"] }
serde = { version = "1", features = ["derive"] }  # If handling JSON

Create a simple web application:

use nimble::{Router, get, post, post_json, Html, Json, Redirect, Text};
use serde::Deserialize;

#[derive(Deserialize)]
struct User {
    name: String,
    age: u8,
}

#[tokio::main]
async fn main() {
    let app = Router::new()
        // GET root path, returns HTML
        .route("/", get(|_| async {
            Html("<h1>Hello World</h1>".to_string())
        }))
        // GET returns JSON
        .route("/json", get(|_| async {
            Json(vec!["apple", "banana", "orange"])
        }))
        // POST handles form (application/x-www-form-urlencoded)
        .route("/user", post(|params| async move {
            let name = params.get("name").unwrap_or(&"Anonymous".to_string()).clone();
            Text(format!("Hello, {}!", name))
        }))
        // POST handles JSON
        .route("/api/user", post_json(|user: User| async move {
            Json(format!("Created user: {}, age: {}", user.name, user.age))
        }))
        // Redirect to Baidu
        .route("/baidu", get(|_| async {
            Redirect("https://www.baidu.com".to_string())
        }));

    // Start the server
    app.run("127.0.0.1", 3000).await;
}

Routes

Nimble currently supports GET and POST methods, with POST further divided into regular form and JSON types.

use nimble::{get, post, post_json};

Router::new()
    .route("/", get(handler_get))
    .route("/submit", post(handler_post))
    .route("/api/data", post_json(handler_post_json));

Note: The current version does not support path parameters (e.g., /users/:id) or methods like PUT and DELETE.

Response Types

Nimble provides various built-in response types, all implementing the IntoResponse trait:

use nimble::{Html, Json, Text, Redirect, File, StatusCode};

// HTML response
Html("<h1>Title</h1>".to_string())

// JSON response (requires the type to implement Serialize)
Json(vec!["apple", "banana", "orange"])

// Plain text response
Text("Hello".to_string())

// Temporary redirect (302)
Redirect("https://example.com".to_string())

// Permanent redirect (301)
Redirect::perm("https://example.com".to_string())

// File response (first parameter: file path, second: force download)
File("static/image.jpg".to_string(), false)   // Display directly
File("file.zip".to_string(), true)            // Download as attachment

// Status code only (empty response)
StatusCode::NOT_FOUND

Additionally, the following types automatically implement IntoResponse:

• &'static str
• String
• Vec<u8>
• ()
• Result<T, E> where both T and E implement IntoResponse

Static File Serving

Router::new() automatically scans the ./static folder in your project root and maps all files to routes.

For example, with the following directory structure:

├── static/
│   ├── css/
│   │   └── style.css
│   ├── js/
│   │   └── app.js
│   └── images/
│       └── logo.png
└── src/
    └── main.rs

After starting the application, you can access files via:

• http://localhost:3000/css/style.css
• http://localhost:3000/js/app.js
• http://localhost:3000/images/logo.png

File Download

Static file routes support force download via the query parameter ?download=true:

http://localhost:3000/images/logo.png?download=true

Request Parameters

GET Requests

GET handlers receive a HashMap<String, String> containing query string parameters from the URL.

use std::collections::HashMap;

async fn search(params: HashMap<String, String>) -> impl IntoResponse {
    let query = params.get("q").unwrap_or(&"".to_string());
    let page = params.get("page").and_then(|p| p.parse::<u32>().ok()).unwrap_or(1);
    Text(format!("Search: {}, Page: {}", query, page))
}

Router::new().route("/search", get(search));

POST Forms

Regular POST handlers also receive a HashMap<String, String>, with data from the application/x-www-form-urlencoded request body.

async fn login(params: HashMap<String, String>) -> impl IntoResponse {
    let username = params.get("username").cloned().unwrap_or_default();
    let password = params.get("password").cloned().unwrap_or_default();
    // Process login...
    Text("Login successful".to_string())
}

POST JSON

Use post_json to automatically deserialize JSON request bodies into the specified type (must implement Deserialize).

use serde::Deserialize;

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

async fn create_user(data: CreateUser) -> impl IntoResponse {
    // Use data.name and data.email
    Json(format!("Created user: {}", data.name))
}

Router::new().route("/users", post_json(create_user));

Error Handling

By returning Result<T, E>, you can easily handle errors, where both T and E must implement IntoResponse.

use nimble::{Text, StatusCode};

async fn get_user() -> Result<Text, StatusCode> {
    // Simulate user lookup
    let user = find_user().await.ok_or(StatusCode::NOT_FOUND)?;
    Ok(Text(format!("Username: {}", user)))
}

Router::new().route("/profile", get(|_| get_user()));

License

This project is licensed under:

• MIT
• Apache-2.0

Author: Wang Xiaoyu Email: wxy6987@outlook.com

You are free to choose either license.