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vweb #

vweb - the V Web Server

A simple yet powerful web server with built-in routing, parameter handling, templating, and other features. The gitly site is based on vweb.

Some features may not be complete, and have some bugs.

Getting start

Just run v new <name> web in your terminal

Features

  • Very fast performance of C on the web.
  • Small binary hello world website is <100 KB.
  • Easy to deploy just one binary file that also includes all templates. No need to install any dependencies.
  • Templates are precompiled all errors are visible at compilation time, not at runtime.

Examples

There are some examples that can be explored here.

And others like:

Front-end getting start example src/main.v

module main

import vweb
import os

struct App {
    vweb.Context
}

struct Object {
    title       string
    description string
}

fn main() {
    vweb.run_at(new_app(), vweb.RunParams{
        port: 8081
    }) or { panic(err) }
}

fn new_app() &App {
    mut app := &App{}
    // makes all static files available.
    app.mount_static_folder_at(os.resource_abs_path('.'), '/')
    return app
}

['/']
pub fn (mut app App) page_home() vweb.Result {
    // all this constants can be accessed by src/templates/page/home.html file.
    page_title := 'V is the new V'
    v_url := 'https://github.com/vlang/v'

    list_of_object := [
        Object{
            title: 'One good title'
            description: 'this is the first'
        },
        Object{
            title: 'Other good title'
            description: 'more one'
        },
    ]
    // $vweb.html() in `<folder>_<name> vweb.Result ()` like this
    // render the `<name>.html` in folder `./templates/<folder>`
    return $vweb.html()
}

$vweb.html() compiles an HTML template into V during compilation, and embeds the resulting code into the current action.

That means that the template automatically has access to that action's entire environment.

src/templates/page/home.html

<html>
  <header>
    <title>${page_title}</title>
    @css 'src/templates/page/home.css'
  </header>
  <body>
    <h1 class="title">Hello, Vs.</h1>
    @for var in list_of_object
    <div>
      <a href="${v_url}">${var.title}</a>
      <span>${var.description}</span>
    </div>
    @end
    <div>@include 'component.html'</div>
  </body>
</html>

src/templates/page/component.html

<div>This is a component</div>

src/templates/page/home.css

h1.title {
  font-family: Arial, Helvetica, sans-serif;
  color: #3b7bbf;
}

V supports Template directives like @css, @js for static files in <path> @if, @for for conditional and loop and @include to include html components.

Deploying vweb apps

Everything, including HTML templates, is in one binary file. That's all you need to deploy.

Getting Started

To start with vweb, you have to import the module vweb and define a struct to hold vweb.Context (and any other variables your program will need). The web server can be started by calling vweb.run(&App{}, port) or vweb.run(&App{}, RunParams)

Example:

import vweb

struct App {
    vweb.Context
}

fn main() {
    vweb.run(&App{}, 8080)
    // // or
    // vweb.run_at(new_app(), vweb.RunParams{
    // 	host: 'localhost'
    // 	port: 8099
    // 	family: .ip
    // }) or { panic(err) }
}

Defining endpoints

To add endpoints to your web server, you have to extend the App struct. For routing you can either use auto-mapping of function names or specify the path as an attribute. The function expects a response of the type vweb.Result.

Example:

// This endpoint can be accessed via http://localhost:port/hello
fn (mut app App) hello() vweb.Result {
    return app.text('Hello')
}

// This endpoint can be accessed via http://localhost:port/foo
["/foo"]
fn (mut app App) world() vweb.Result {
    return app.text('World')
}

- HTTP verbs

To use any HTTP verbs (or methods, as they are properly called), such as [post], [get], [put], [patch] or [delete] you can simply add the attribute before the function definition.

Example:

[post]
fn (mut app App) world() vweb.Result {
    return app.text('World')
}

['/product/create'; post]
fn (mut app App) create_product() vweb.Result {
    return app.text('product')
}

- Parameters

Parameters are passed direcly in endpoint route using colon sign : and received using the same name at function To pass a parameter to an endpoint, you simply define it inside an attribute, e. g. ['/hello/:user]. After it is defined in the attribute, you have to add it as a function parameter.

Example:

          vvvv
['/hello/:user']            vvvv
fn (mut app App) hello_user(user string) vweb.Result {
    return app.text('Hello $user')
}

You have access to the raw request data such as headers or the request body by accessing app (which is vweb.Context). If you want to read the request body, you can do that by calling app.req.data. To read the request headers, you just call app.req.header and access the header you want example. app.req.header.get(.content_type). See struct Header for all available methods (v doc net.http Header). It has, too, fields for the query, form, files.

- Query

To handle the query context, you just need use the query field

Example:

module main

import vweb

struct App {
    vweb.Context
}

fn main() {
    vweb.run(&App{}, 8081)
}

['/user'; get]
pub fn (mut app App) controller_get_user_by_id() vweb.Result {
    // http://localhost:3000/user?q=vpm&order_by=desc => { 'q': 'vpm', 'order_by': 'desc' }
    return app.text(app.query.str())
}

Middleware

V haven't a well defined middleware. For now, you can use before_request(). This method called before every request. Probably you can use it for check user session cookie or add header Example:

pub fn (mut app App) before_request() {
    app.user_id = app.get_cookie('id') or { '0' }
}

Redirect

Used when you want be redirected to an url Examples:

pub fn (mut app App) before_request() {
    app.user_id = app.get_cookie('id') or { app.redirect('/') }
}

['/articles'; get]
pub fn (mut app App) articles() vweb.Result {
    if !app.token {
        app.redirect('/login')
    }
    return app.text("patatoes")
}

Responses

- set_status

Sets the response status Example:

['/user/get_all'; get]
pub fn (mut app App) controller_get_all_user() vweb.Result {
    token := app.get_header('token')

    if !token {
        app.set_status(401, '')
        return app.text('Not valid token')
    }

    response := app.service_get_all_user() or {
        app.set_status(400, '')
        return app.text('$err')
    }
    return app.json(response)
}

- html

Response HTTP_OK with payload with content-type text/html Example:

pub fn (mut app App) html_page() vweb.Result {
    return app.html('<h1>ok</h1>')
}

- text

Response HTTP_OK with payload with content-type text/plain Example:

pub fn (mut app App) simple() vweb.Result {
    return app.text('A simple result')
}

- json

Response HTTP_OK with payload with content-type application/json Examples:

['/articles'; get]
pub fn (mut app App) articles() vweb.Result {
    articles := app.find_all_articles()
    json_result := json.encode(articles)
    return app.json(json_result)
}

['/user/create'; post]
pub fn (mut app App) controller_create_user() vweb.Result {
    body := json.decode(User, app.req.data) or {
        app.set_status(400, '')
        return app.text('Failed to decode json, error: $err')
    }

    response := app.service_add_user(body.username, body.password) or {
        app.set_status(400, '')
        return app.text('error: $err')
    }

    return app.json(response)
}

- json_pretty

Response HTTP_OK with a pretty-printed JSON result Example:

fn (mut app App) time_json_pretty() {
    app.json_pretty({
        'time': time.now().format()
    })
}

- file

Response HTTP_OK with file as payload

- ok

Response HTTP_OK with payload Example:

['/form_echo'; post]
pub fn (mut app App) form_echo() vweb.Result {
    app.set_content_type(app.req.header.get(.content_type) or { '' })
    return app.ok(app.form['foo'])
}

- server_error

Response a server error Example:

fn (mut app App) sse() vweb.Result {
    return app.server_error(501)
}

- not_found

Response HTTP_NOT_FOUND with payload Example:

['/:user/:repo/settings']
pub fn (mut app App) user_repo_settings(username string, repository string) vweb.Result {
    if username !in known_users {
        return app.not_found()
    }
    return app.html('username: $username | repository: $repository')
}

Requests

- get_header

Returns the header data from the key Example:

['/user/get_all'; get]
pub fn (mut app App) controller_get_all_user() vweb.Result {
    token := app.get_header('token')
    return app.text(token)
}

- get_cookie

Sets a cookie Example:

pub fn (mut app App) before_request() {
    app.user_id = app.get_cookie('id') or { '0' }
}

- add_header

Adds an header to the response with key and val Example:

['/upload'; post]
pub fn (mut app App) upload() vweb.Result {
    fdata := app.files['upfile']

    data_rows := fdata[0].data.split('\n')

    mut output_data := ''

    for elem in data_rows {
        delim_row := elem.split('\t')
        output_data += '${delim_row[0]}\t${delim_row[1]}\t'
        output_data += '${delim_row[0].int() + delim_row[1].int()}\n'
    }

    output_data = output_data.all_before_last('\n')

    app.add_header('Content-Disposition', 'attachment; filename=results.txt')
    app.send_response_to_client('application/octet-stream', output_data)

    return $vweb.html()
}

- set_cookie

Sets a cookie Example:

pub fn (mut app App) cookie() vweb.Result {
    app.set_cookie(name: 'cookie', value: 'test')
    return app.text('Response Headers\n$app.header')
}

- set_cookie_with_expire_date

Sets a cookie with a expire_data Example:

pub fn (mut app App) cookie() vweb.Result {
    key := 'cookie'
    value := 'test'
    duration := time.Duration(2 * time.minute ) // add 2 minutes
    expire_date := time.now().add(duration)

    app.set_cookie_with_expire_date(key, value, expire_date)
    return app.text('Response Headers\n$app.header')
}

- set_content_type

Sets the response content type Example:

['/form_echo'; post]
pub fn (mut app App) form_echo() vweb.Result {
    app.set_content_type(app.req.header.get(.content_type) or { '' })
    return app.ok(app.form['foo'])
}

Template

-handle_static

handle_static is used to mark a folder (relative to the current working folder) as one that contains only static resources (css files, images etc).

If root is set the mount path for the dir will be in '/'

Example:

fn main() {
    mut app := &App{}
    app.serve_static('/favicon.ico', 'favicon.ico')
    // Automatically make available known static mime types found in given directory.
    os.chdir(os.dir(os.executable()))?
    app.handle_static('assets', true)
    vweb.run(app, port)
}

-mount_static_folder_at

makes all static files in directory_path and inside it, available at http://server/mount_path.

For example: suppose you have called .mount_static_folder_at('/var/share/myassets', '/assets'), and you have a file /var/share/myassets/main.css . => That file will be available at URL: http://server/assets/main.css .

-serve_static

Serves a file static. url is the access path on the site, file_path is the real path to the file, mime_type is the file type

Example:

fn main() {
    mut app := &App{}
    app.serve_static('/favicon.ico', 'favicon.ico')
    app.mount_static_folder_at(os.resource_abs_path('.'), '/')
    vweb.run(app, 8081)
}

Others

-ip

Returns the ip address from the current user

Example:

pub fn (mut app App) ip() vweb.Result {
    ip := app.ip()
    return app.text('ip: $ip')
}

-error

Set a string to the form error

Example:

pub fn (mut app App) error() vweb.Result {
    app.error('here as an error')
    println(app.form_error) //'vweb error: here as an error'
}

Cross-Site Request Forgery (CSRF) protection

Provides protection against Cross-Site Request Forgery

Usage

When building a csrf-protected service, first of all create a structthat implements csrf.App

module main

import vweb
import vweb.csrf

// embeds the csrf.App struct in order to empower the struct to protect against CSRF
struct App {
    csrf.App
}

Start a server e.g. in the main function.

fn main() {
    vweb.run_at(&App{}, vweb.RunParams{
        port: 8080
    }) or { panic(err) }
}

Enable CSRF-protection

Then add a handler-function to define on which route or on which site the CSRF-Token shall be set.

fn (mut app App) index() vweb.Result {

    // Set a Csrf-Cookie (Token will be generated automatically)
    app.set_csrf_cookie()

    // Get the token-value from the csrf-cookie that was just setted
    token := app.get_csrf_token() or { panic(err) }

    return app.text("Csrf-Token set! It's value is: $token")
}

If you want to set the cookies's HttpOnly-status to false in order to make it
accessible to scripts on your site, you can do it like this: app.set_csrf_cookie(csrf.HttpOnly{false}) If no argument is passed the value will be set to true by default.

Protect against CSRF

If you want to protect a route or a site against CSRF just add
app.csrf_protect() at the beginning of the handler-function.

fn (mut app App) foo() vweb.Result {
    // Protect this handler-function against CSRF
    app.csrf_protect()
    return app.text("Checked and passed csrf-guard")
}

Constants #

const (
	methods_with_form = [http.Method.post, .put, .patch]
	headers_close     = http.new_custom_header_from_map({
		'Server':                           'VWeb'
		http.CommonHeader.connection.str(): 'close'
	}) or { panic('should never fail') }

	http_302          = http.new_response(
		status: .found
		body: '302 Found'
		header: headers_close
	)
	http_400          = http.new_response(
		status: .bad_request
		body: '400 Bad Request'
		header: http.new_header(
			key: .content_type
			value: 'text/plain'
		).join(headers_close)
	)
	http_404          = http.new_response(
		status: .not_found
		body: '404 Not Found'
		header: http.new_header(
			key: .content_type
			value: 'text/plain'
		).join(headers_close)
	)
	http_500          = http.new_response(
		status: .internal_server_error
		body: '500 Internal Server Error'
		header: http.new_header(
			key: .content_type
			value: 'text/plain'
		).join(headers_close)
	)
	mime_types        = {
		'.aac':    'audio/aac'
		'.abw':    'application/x-abiword'
		'.arc':    'application/x-freearc'
		'.avi':    'video/x-msvideo'
		'.azw':    'application/vnd.amazon.ebook'
		'.bin':    'application/octet-stream'
		'.bmp':    'image/bmp'
		'.bz':     'application/x-bzip'
		'.bz2':    'application/x-bzip2'
		'.cda':    'application/x-cdf'
		'.csh':    'application/x-csh'
		'.css':    'text/css'
		'.csv':    'text/csv'
		'.doc':    'application/msword'
		'.docx':   'application/vnd.openxmlformats-officedocument.wordprocessingml.document'
		'.eot':    'application/vnd.ms-fontobject'
		'.epub':   'application/epub+zip'
		'.gz':     'application/gzip'
		'.gif':    'image/gif'
		'.htm':    'text/html'
		'.html':   'text/html'
		'.ico':    'image/vnd.microsoft.icon'
		'.ics':    'text/calendar'
		'.jar':    'application/java-archive'
		'.jpeg':   'image/jpeg'
		'.jpg':    'image/jpeg'
		'.js':     'text/javascript'
		'.json':   'application/json'
		'.jsonld': 'application/ld+json'
		'.mid':    'audio/midi audio/x-midi'
		'.midi':   'audio/midi audio/x-midi'
		'.mjs':    'text/javascript'
		'.mp3':    'audio/mpeg'
		'.mp4':    'video/mp4'
		'.mpeg':   'video/mpeg'
		'.mpkg':   'application/vnd.apple.installer+xml'
		'.odp':    'application/vnd.oasis.opendocument.presentation'
		'.ods':    'application/vnd.oasis.opendocument.spreadsheet'
		'.odt':    'application/vnd.oasis.opendocument.text'
		'.oga':    'audio/ogg'
		'.ogv':    'video/ogg'
		'.ogx':    'application/ogg'
		'.opus':   'audio/opus'
		'.otf':    'font/otf'
		'.png':    'image/png'
		'.pdf':    'application/pdf'
		'.php':    'application/x-httpd-php'
		'.ppt':    'application/vnd.ms-powerpoint'
		'.pptx':   'application/vnd.openxmlformats-officedocument.presentationml.presentation'
		'.rar':    'application/vnd.rar'
		'.rtf':    'application/rtf'
		'.sh':     'application/x-sh'
		'.svg':    'image/svg+xml'
		'.swf':    'application/x-shockwave-flash'
		'.tar':    'application/x-tar'
		'.tif':    'image/tiff'
		'.tiff':   'image/tiff'
		'.ts':     'video/mp2t'
		'.ttf':    'font/ttf'
		'.txt':    'text/plain'
		'.vsd':    'application/vnd.visio'
		'.wav':    'audio/wav'
		'.weba':   'audio/webm'
		'.webm':   'video/webm'
		'.webp':   'image/webp'
		'.woff':   'font/woff'
		'.woff2':  'font/woff2'
		'.xhtml':  'application/xhtml+xml'
		'.xls':    'application/vnd.ms-excel'
		'.xlsx':   'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet'
		'.xml':    'application/xml'
		'.xul':    'application/vnd.mozilla.xul+xml'
		'.zip':    'application/zip'
		'.3gp':    'video/3gpp'
		'.3g2':    'video/3gpp2'
		'.7z':     'application/x-7z-compressed'
	}
	max_http_post_size = 1024 * 1024
	default_port       = 8080
)

fn not_found #

fn not_found() Result

Returns an empty result

fn run #

fn run[T](global_app &T, port int)

run - start a new VWeb server, listening to all available addresses, at the specified port

fn run_at #

fn run_at[T](global_app &T, params RunParams) !

run_at - start a new VWeb server, listening only on a specific address host, at the specified port

Example

vweb.run_at(new_app(), vweb.RunParams{ host: 'localhost' port: 8099 family: .ip }) or { panic(err) }

type RawHtml #

type RawHtml = string

A type which don't get filtered inside templates

struct Context #

struct Context {
mut:
	content_type string = 'text/plain'
	status       string = '200 OK'
pub:
// HTTP Request
	req http.Request
// TODO Response
pub mut:
	done bool
// time.ticks() from start of vweb connection handle.
// You can use it to determine how much time is spent on your request.
	page_gen_start i64
// TCP connection to client.
// But beware, do not store it for further use, after request processing vweb will close connection.
	conn              &net.TcpConn = unsafe { nil }
	static_files      map[string]string
	static_mime_types map[string]string
// Map containing query params for the route.
// http://localhost:3000/index?q=vpm&order_by=desc => { 'q': 'vpm', 'order_by': 'desc' }
	query map[string]string
// Multipart-form fields.
	form map[string]string
// Files from multipart-form.
	files map[string][]http.FileData

	header http.Header // response headers
// ? It doesn't seem to be used anywhere
	form_error string
}

The Context struct represents the Context which hold the HTTP request and response.
It has fields for the query, form, files.

fn (Context) init_server #

fn (ctx Context) init_server()

Defining this method is optional.
This method called at server start.
You can use it for initializing globals.

fn (Context) before_request #

fn (ctx Context) before_request()

Defining this method is optional.
This method called before every request (aka middleware).
Probably you can use it for check user session cookie or add header.

fn (Context) send_response_to_client #

fn (mut ctx Context) send_response_to_client(mimetype string, res string) bool

TODO - test vweb intern function

fn (Context) html #

fn (mut ctx Context) html(s string) Result

Response HTTP_OK with s as payload with content-type text/html

fn (Context) text #

fn (mut ctx Context) text(s string) Result

Response HTTP_OK with s as payload with content-type text/plain

fn (Context) json #

fn (mut ctx Context) json[T](j T) Result

Response HTTP_OK with json_s as payload with content-type application/json

fn (Context) json_pretty #

fn (mut ctx Context) json_pretty[T](j T) Result

Response HTTP_OK with a pretty-printed JSON result

fn (Context) file #

fn (mut ctx Context) file(f_path string) Result

TODO - test Response HTTP_OK with file as payload

fn (Context) ok #

fn (mut ctx Context) ok(s string) Result

Response HTTP_OK with s as payload

fn (Context) server_error #

fn (mut ctx Context) server_error(ecode int) Result

TODO - test Response a server error

fn (Context) redirect #

fn (mut ctx Context) redirect(url string) Result

Redirect to an url

fn (Context) not_found #

fn (mut ctx Context) not_found() Result

Send an not_found response

fn (Context) set_content_type #

fn (mut ctx Context) set_content_type(typ string)

Sets the response content type

fn (Context) set_status #

fn (mut ctx Context) set_status(code int, desc string)

TODO - test Sets the response status

fn (Context) add_header #

fn (mut ctx Context) add_header(key string, val string)

TODO - test Adds an header to the response with key and val

fn (Context) get_header #

fn (ctx &Context) get_header(key string) string

TODO - test Returns the header data from the key

fn (Context) handle_static #

fn (mut ctx Context) handle_static(directory_path string, root bool) bool

handle_static is used to mark a folder (relative to the current working folder) as one that contains only static resources (css files, images etc).
If root is set the mount path for the dir will be in '/' Usage:

os.chdir( os.executable() )?
app.handle_static('assets', true)

fn (Context) mount_static_folder_at #

fn (mut ctx Context) mount_static_folder_at(directory_path string, mount_path string) bool

TODO - test mount_static_folder_at - makes all static files in directory_path and inside it, available at http://server/mount_path For example: suppose you have called .mount_static_folder_at('/var/share/myassets', '/assets'), and you have a file /var/share/myassets/main.css .
=> That file will be available at URL: http://server/assets/main.css .

fn (Context) serve_static #

fn (mut ctx Context) serve_static(url string, file_path string)

TODO - test Serves a file static url is the access path on the site, file_path is the real path to the file, mime_type is the file type

fn (Context) ip #

fn (ctx &Context) ip() string

Returns the ip address from the current user

fn (Context) error #

fn (mut ctx Context) error(s string)

Set s to the form error

struct Result #

struct Result {}

A dummy structure that returns from routes to indicate that you actually sent something to a user

struct RunParams #

struct RunParams {
	host   string
	port   int = 8080
	family net.AddrFamily = .ip6 // use `family: .ip, host: 'localhost'` when you want it to bind only to 127.0.0.1
}
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