Guide - Web Programming with F#

F# excels at building efficient, scalable and robust web solutions. Web programming is based around receiving a single HTTP request and replying with a result, which maps very well to a stateless, functional approach. Advantages to using F# for web programming include:

• Fast - F# code execution is fast, using native code generation from scripted or project code

• Succinct - F# is concise, readable and type-safe, for fast development of robust web solutions

• Reactive and Scalable - F# asynchronous programming simplifies scalable, reactive web programming

• Interoperable - F# interoperates seamlessly with languages such as C#, JavaScript and TypeScript

• JavaScript-ready - F# is JavaScript-ready through WebSharper and Fable

• Open-source and cross-platform

• Integrated Stacks
  • SAFE Stack
  • WebSharper
  • Fable
• Web Frameworks
  • Giraffe
  • ASP.NET Core
  • Suave
  • Saturn
  • Bolero
  • Falco
  • ServiceStack
• Web Testing Frameworks
  • Canopy for Client-side Testing
  • Unit Testing Libraries
• Live Examples
  • TodoBackend
• Tutorials
• Books
• Presentations
• Hosting

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Integrated Stacks

SAFE Stack

 SAFE Stack is an end-to-end, functional-first stack for cloud-ready web development that emphasizes type-safe programming. It is an application development stack that brings several technologies together into a single, coherent stack for type-safe, flexible, web-enabled applications that can be written almost entirely in F#.

• Getting Started
• Docs
• Dojo
• Support

WebSharper

 WebSharper allows end-to-end web applications with both client and server developed in F#. It includes TypeScript interoperability, mobile web apps, getting started material, templates and much more.

• Try Online

• Documentation

• Forums

Fable

 Fable is an F# to JS compiler designed to generate clean and standard code in order to maximize interoperability in both ways. It integrates with most of JS development pipelines like Babel, Webpack or React Hot Loader. Fable allows you to develop node.js services, desktop apps with Electron and mobile apps with React native.

• Try Online
• Docs

Web Frameworks

Giraffe

 Giraffe is an F# library for building rich web applications that use ASP.NET Core under the hood. It has been heavily inspired and is similar to Suave, but has been specifically designed with ASP.NET Core in mind and can be plugged into the ASP.NET Core pipeline via middleware.

• Docs
• Samples
• Blog post showing how to use it with .NET Core 2.0

ASP.NET Core

ASP.NET Core is a modern, cross-platform, high-performance, open-source framework for building modern, cloud-based, Internet-connected applications. It runs on .NET Core and supports F# out of the box. If you install the .NET Core SDK, there are F# templates available via the dotnet new command.

• Docs

Suave

 Suave is a simple web development F# library providing a lightweight web server and a set of combinators to manipulate route flow and task composition.

Saturn

 Saturn is a web development framework written in F# which implements the server-side MVC pattern. Many of its components and concepts will seem familiar to anyone with experience in other web frameworks like Ruby on Rails or Python’s Django. It’s built on top of Giraffe and ASP.Net Core - modern, cross-platform, high-performance development platform for building cloud-ready web applications.

It’s heavily inspired by Elixir’s Phoenix.

• NuGet
• GitHub
• Docs
• Install the project template with dotnet new --install Saturn.Template

Bolero

 Bolero - F# on the client side, no JavaScript - Bolero uses Blazor to bring F# to WebAssembly. Create dynamic HTML content using syntax familiar from WebSharper and Fable, in a full-fledged client-side .NET web framework.

• Get Started
• Project Template
• Try Online

Falco

Falco is a functional-first toolkit for building brilliant ASP.NET Core applications using F#. It is built upon the high-performance primitives of ASP.NET Core, optimized for building HTTP applications quickly, and seamlessly integrates with existing .NET Core middleware and frameworks.

• NuGet
• GitHub
• Docs
• Install the project template with dotnet new -i "Falco.Template::*"

ServiceStack

ServiceStack is a framework for simple and fast web services on .NET.

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Web Testing Frameworks

Canopy for Client-side Testing

canopy is a web testing framework built on top of selenium and written in F#. It’s syntax is clean and concise. You can easily leverage your existing .NET code to help you test.

Unit Testing Libraries

Some open source libraries that assist with web unit testing are:

• Expecto - An evolution of Fuchu

• FsCheck

• FsUnit

• Fuchu

• TickSpec

• Unquote

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Live Examples

TodoBackend

TodoBackend is a project that aims to be “a shared example to showcase backend tech stacks.” The F# community has contributed some examples, and a few more are in progress:

• F# - Freya (OWIN)

• F# - ASP.NET Web API

Please consider contributing, either directly to the TodoBackend project or via the TodoBackendFSharp project.

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Tutorials

• Suave Music Store Tutorial for creating applications with Suave.IO

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Books

Several books have been written that include information on building web applications with F#:

• Building Web, Cloud, and Mobile Solutions with F#

• Expert F# 4.0

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Presentations

There are several presentations and tutorials available that include information on build web applications with F#:

• Taking F# to the Masses with CloudSharper

• F# on the Web

• Tackle UI with Reactive DOM in F# and WebSharper

• Building an HTML5 application with WebSharper Sitelets, Part 1

• Building Better Web Apps with F#

• Building Data-Driven Websites

• F# on the Web Workshop

• F# 3.0: data, services, Web, cloud, at your fingertips

• F# Introduction

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Hosting

Common hosting options are:

• Heroku - See, for example, F#, ServiceStack and Heroku and complete article about hosting NancyFx and F# on Heroku

• Azure Web Sites - Create and deploy to free Azure web sites from Visual Studio and other tools

• AppHarbor - Free hosting of .NET web applications

• GearHost - Free hosting of .NET web applications (100 MB), IIS based, support for both .NET Framework and Core, MSSQL and MySQL databases (10 MB), support of simple WebJobs.