Odiel

Odiel is a lightweight and easy-to-use HTTP framework for the D programming language. It is designed to be simple, fast, and flexible, allowing developers to quickly build scalable web applications.

Features

• Fast and lightweight
• Easy-to-use API
• Supports HTTP/1.1 and HTTP/2 protocols
• Built-in routing and middleware system
• Supports templating engines such as Mustache and Handlebars
• Built-in support for JSON and XML validation
• Can be used with any frontend framework
• Includes built-in support for web sockets
• Highly modular and customizable

Getting Started

To get started with Odiel, you first need to install it using DUB (the D package manager):

$ dub init myproject
$ cd myproject
$ dub add odiel

Once you have installed Odiel, you can start building your application by creating an instance of the App class:

import odiel;

void main()
{
    auto app = new App();

    app.get("/", (req, res) =>
    {
        res.send("Hello, world!");
    });

    app.listen(8080);
}

In this example, we create a new App instance and define a route for the root URL ("/") using the get method. When a GET request is made to the root URL, the provided callback function is executed and a "Hello, world!" response is sent using the send method of the res object. Finally, we start the server by calling the listen method with the desired port number.

Routing

Odiel provides a built-in routing system that allows you to define URL patterns and map them to callback functions. Here is an example of how to define a basic route:

app.get("/users/:id", (req, res) =>
{
    auto id = req.params["id"];
    res.send("User ID: " ~ id);
});

In this example, we define a route for URLs of the form "/users/:id", where ":id" is a dynamic parameter that can match any value. When a request is made to a URL that matches this pattern, the callback function is executed and the req.params dictionary is populated with the dynamic parameter values.

Middleware

Odiel also provides a middleware system that allows you to intercept and modify requests and responses before they are processed by your application. Here is an example of how to define a middleware function:

void logger(Request req, Response res, NextFn next)
{
    auto start = Clock.currTime();

    next();

    auto end = Clock.currTime();
    auto duration = end - start;

    writefln("%s %s %dms", req.method, req.url.path, duration.msecs);
}

app.use(logger);

In this example, we define a logger middleware function that logs the duration of each request to the console. The next function is called to pass control to the next middleware function or route handler in the chain.

Templating

Odiel supports a variety of templating engines, including Mustache and Handlebars. Here is an example of how to use Mustache templates in your application:

import odiel;
import odiel.mustache;

void main()
{
    auto app = new App();
    app.use(new MustacheRenderer());

    app.get("/", (req, res) =>
    {
        res.render("index", { name: "John Doe" });
    });

    app.listen(8080);
}

In this example, we create a new MustacheRenderer instance and add it to our application's middleware chain using the use method. We then define a route for the root URL and render a Mustache template named "index" with the context object { name: "John Doe" }.

Conclusion

Odiel is a powerful and flexible HTTP framework for the D programming language that can help you quickly build scalable and robust web applications. With its easy-to-use API, built-in routing and middleware system, and support for popular templating engines, Odiel is a great choice for both beginner and advanced developers alike.