Deno-Spring

A compact, high-performance and full-featured web server framework in Deno.

Shortcut mode

Create a mod.ts file and write the following content, then run deno run --allow-all mod.ts.

import { Bootstrap, Server } from "https://deno.land/x/spring/mod.ts";

@Bootstrap
export default class {
    constructor(app: Server) {
        app.get("/:id", (ctx) => {
            return "hello " + ctx.params.id;
        });
    }
}

Note that features such as components, template engine and unified error handling cannot be used in shortcut mode, you must solve them in other ways.

Decorator mode

Decorator mode and shortcut mode do not conflict and can be used together. The only difference in performance between the two is that the latter needs to parse all decorators at startup, it is almost the same in runtime.

In decorator mode, you must first create a configuration file named deno.jsonc with the following content:

{
    "compilerOptions": {
        "emitDecoratorMetadata": true,
    }
}

Then modify the content of mod.ts as follows, in order to inject all components with decorators into the application by app.modules method.

@Bootstrap
export default class {
    constructor(app: Server) {
        app.modules(Authenticator, ErrorController, UserController, UserService);
        app.assets("/static/*");
    }
}

1. Interceptor

The interceptor is not required, but if there is one, the methods in it will be executed in order.

// Authenticator.ts
@Interceptor
export class Authenticator {
    cors(ctx: Context) {
        // do something first
    }
    auth(ctx: Context) {
        // do something second
    }
}

2. ErrorHandler

If an error handler component is defined, all errors within the framework will be handled by it.

// ErrorController.ts
@Component
export class ErrorController {
    @ErrorHandler
    error(ctx: Context, err: Error) {
        return {
            status: ctx.status,
            message: err.message,
        };
    }
}

3. Controller

Create a routing controller and inject a service class.

// UserController.ts
@Controller("/prefix")
export class UserController {
    @Autowired
    userService!: UserService;

    @Get("/:id")
    getUser(ctx: Context) {
        return this.userService.getUser(ctx.params.id);
    }
}

If you want to use the service class in the constructor, you need to refer to the following usage:

// UserController.ts
@Controller("/prefix")
export class UserController {
    constructor(public userService: UserService) {
        this.userService.init();
    }

    @Get("/:id")
    getUser(ctx: Context) {
        return this.userService.getUser(ctx.params.id);
    }
}

4. Component

// UserService.ts
@Component
export class UserService {
    getUser(id: string) {
        // do something
    }
}

5. View

View decorator are used to decorate controller methods, and its parameter is the template file path. After adding it, the built-in template engine will be used for rendering automatically. The built-in engine syntax see SYNTAX.md

// mod.ts
@Bootstrap
export default class {
    constructor(app: Server) {
        app.modules(Authenticator, ErrorController, UserController, UserService);
        app.assets("/assets/*");

        // Add the following code for template engine
        app.views("./views");
        app.imports({ formatDate });
    }
}

// UserController.ts
@Controller("/prefix")
export class UserController {
    @Autowired
    userService!: UserService;

    @Get("/:id")
    @View("index.html") // or @View("./project/path/index.html") if options not initialized
    getUser(ctx: Context) {
        return this.userService.getUser(ctx.params.id);
    }
}

// index.html
<h1>Hello, {{= name }} {{= formatDate(birthdate) }}</h1>

API Reference

app: Server

• app.port HTTP server listening port, default 3000.
• app.hostname HTTP server hostname, default “0.0.0.0”
• app.views The root of template files, default “”
• app.imports Global imports for template, default {}
• app.assets The paths of static resources
• app.modules Load classes that need to use decorator in the application
• app.get, app.post, app.put… Request methods with (path, handler) parameters

Decorators

Context

Context is an instance passed to controllers, Interceptors and error handler, it contains properties and methods related to requests and responses.

Request Properties

• ctx.params The parameters on route path
• ctx.query The parameters on query string
• ctx.url ex. https://example.com:3000/users?page=1
• ctx.origin ex. https://example.com:3000
• ctx.protocol ex. https:
• ctx.host ex. example.com:3000
• ctx.hostname ex. example.com
• ctx.port ex. 3000
• ctx.path ex. /users
• ctx.method Standard http request methods
• ctx.has, ctx.get Shortcuts for obtain reqeust headers. Refer to https://deno.com/deploy/docs/runtime-headers
• ctx.cookies Including one method to get request cookie: ctx.cookies.get(name)
• ctx.text, ctx.json, ctx.form, ctx.blob, ctx.buffer Promised methods to parse request body.

Response Properties

• ctx.status
• ctx.status=
• ctx.statusText
• ctx.statusText=
• ctx.cookies Including two methods to operate response cookie: set(name, value),delete(name)

Response Methods

• ctx.set(name, value) The following 3 methods are used to manipulate response headers
• ctx.redirect(url[, status]) Redirect url with default status code 308.

Others

• ctx.view(tmplFile, data) If the controller method does not add a @View decorator, you can call this method to return the rendered text content.
• ctx.render(tmplText, data) Render template text, usually not needed.

Return types

Controller methods are allowed to return the following object types:

• BodyInit: Blob, BufferSource, FormData, ReadableStream, URLSearchParams, or USVString
• Response: Native response instance.