Maia - Web Framework for Nim

Maia is a simple and powerful asynchronous web framework written in Nim, designed to build fast and scalable web applications. It provides routing, middleware support, filters, hooks, file handling, and more.

Features

• Routing: Define routes and handlers easily.
• Middlewares: Apply custom middlewares to routes.
• Asynchronous: Built with asynchronous execution in mind.
• Stream Support: Send chunked data or Server-Sent Events (SSE).
• Request Hooks: Pre- and post-processing hooks for custom behavior.
• Filters: Apply request filters like authentication.
• Static Files: Serve static files or send specific files for download.
• Error Handling: Custom error handlers to manage exceptions.
• Multiple Routers: Support for extending routers.

Getting Started

Installation

1. Install the Nim language from nim-lang.org.
2. Install Maia by cloning the repository or using a package manager (if available).

Hello World Example

import maia

proc handler(req: Request, res: Response): Future[Response] {.async.} =
    await res.send("Hello World!")

let router = newRouter()
    .register(get("/", handler))

discard newHttpServer(router)
    .setConfig(Config(port: 5000))
    .start()

This simple example sets up a web server on port 5000 that returns "Hello World!" for requests to the root route (/).

Redirect Example

import maia

proc handler(req: Request, res: Response): Future[Response] {.async.} =
    await res.redirect("/endpoint")

proc handler2(req: Request, res: Response): Future[Response] {.async.} =
    await res.send("Redirected!")

let router = newRouter()
    .register(get("/", handler))
    .register(get("/endpoint", handler2))

discard newHttpServer(router)
    .setConfig(Config(port: 5000))
    .start()

This example redirects requests from / to /endpoint.

Handling Query Parameters

import maia

proc handler(req: Request, res: Response): Future[Response] {.async.} =
    let name = req.query.getString("name")
    await res.send("Welcome " & name)

let router = newRouter()
    .register(get("/", handler))

discard newHttpServer(router)
    .setConfig(Config(port: 5000))
    .start()

Extract query parameters from the URL and respond accordingly.

Handling POST Requests

import maia

proc handler(req: Request, res: Response): Future[Response] {.async.} =
    let form = req.form.get()
    let name = form.getString("name")
    await res.send("Welcome " & name)

let router = newRouter()
    .register(post("/form", handler))

discard newHttpServer(router)
    .setConfig(Config(port: 5000))
    .start()

Handle POST requests, process form data, and send a response.

Middleware Example

import maia

proc handler(req: Request, res: Response): Future[Response] {.async.} =
    await res.send("Hello World!")

proc myMiddleware(req: Request, res: Response, next: Handler): Future[Response] {.async.} =
    echo "Middleware executed!"
    await next(req, res)

let router = newRouter()
    .register(get("/", handler).apply(myMiddleware))

discard newHttpServer(router)
    .setConfig(Config(port: 5000))
    .start()

Add middleware to log requests or manipulate the request/response pipeline.

Streams and Server-Sent Events (SSE)

import maia

proc handler(req: Request, res: Response): Future[Response] {.async.} =
    await res.prepare()
    await res.write("Chunked")
    await sleepAsync(5.seconds)
    await res.write("Stream")
    await res.finish()

proc handler2(req: Request, res: Response): Future[Response] {.async.} =
    await res.prepare(HttpResponseStreamType.SSE)
    await res.event("stream", "SSE Event")
    await sleepAsync(5.seconds)
    await res.event("stream", "Stream")
    await res.finish()

let router = newRouter()
    .register(get("/chunks", handler))
    .register(get("/event", handler2))

discard newHttpServer(router)
    .setConfig(Config(port: 5000))
    .start()

Handle chunked responses and Server-Sent Events (SSE) for real-time data streaming.

Filters (Authentication Example)

import maia

proc handler(req: Request, res: Response): Future[Response] {.async.} =
    await res.send("Authenticated!")

let token = "your_auth_token"
let authFilter = Filter(code: Http401, body: "Authorization token required!")
    .headerEqTo("Authorization", token)

let router = newRouter()
    .register(get("/", handler))
    .setFilter(authFilter)

discard newHttpServer(router)
    .setConfig(Config(port: 5000))
    .start()

Apply request filters for authentication or other request validation.

Error Handling Example

import maia

proc handler(req: Request, res: Response): Future[Response] {.async.} =
    await res.error(Http400, "Bad Request")

proc errorHandler(req: Request, res: Response, exc: ref Exception): Future[Response] {.async.} =
    await res.setStatus(Http500).send("An error occurred")

let router = newRouter()
    .setErrHandler(errorHandler)
    .register(get("/", handler))

discard newHttpServer(router)
    .setConfig(Config(port: 5000))
    .start()

Handle errors gracefully with custom error handlers.

Conclusion

Maia makes it easy to develop fast, flexible, and scalable web applications in Nim. With support for routing, middleware, filters, and more, it is a lightweight framework that gives you full control over your web services.