Getting Started with DocFX

1. What is DocFX

DocFX is an API documentation generator for .NET, which currently supports C#, VB and F#. It generates API reference documentation from triple-slash comments in your source code. It also allows you to use Markdown files to create additional topics such as tutorials and how-tos, and to customize the generated reference documentation. DocFX builds a static HTML website from your source code and Markdown files, which can be easily hosted on any web server (for example, github.io). Also, DocFX provides you the flexibility to customize the layout and style of your website through templates. If you are interested in creating your own website with your own styles, you can follow how to create custom template to create custom templates.

DocFX also has the following cool features:

  • Integration with your source code. You can click "View Source" on an API to navigate to the source code in GitHub (your source code must be pushed to GitHub).
  • Cross-platform support. We have an exe version that runs natively on Windows and with Mono it can also run on Linux and macOS.
  • Integration with Visual Studio. You can seamlessly use DocFX within Visual Studio.
  • Markdown extensions. We introduced DocFX Flavored Markdown(DFM) to help you write API documentation. DFM is 100% compatible with GitHub Flavored Markdown(GFM) with some useful extensions, like file inclusion, code snippet, cross reference, and yaml header. For a detailed description about DFM, please refer to DFM.
Warning

Prerequisites Visual Studio 2019 is needed for docfx metadata msbuild projects. It's not required when generating metadata directly from source code (.cs, .vb) or assemblies (.dll)

2. Use DocFX as a command-line tool

Step1. Install DocFX. Choose from one of the following sources:

  • Chocolatey: choco install docfx -y.
  • Homebrew (owned by community):
    • Intel chip: brew install docfx.
    • M1 chip: DocFX doesn't support the new mac M1 chips so you will need to use Rosetta to run it. Follow these steps:
      • Uninstall Homebrew
      • Re-install brew with the following command: arch -x86_64 /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
      • Install docfx: arch -x86_64 brew install docfx
      • Run docfx: arch -x86_64 docfx path/to/docfx.json --serve
  • GitHub: download and unzip docfx.zip from https://github.com/dotnet/docfx/releases, extract it to a local folder, and add it to PATH so you can run it anywhere.
  • NuGet: nuget install docfx.console. docfx.exe is under folder docfx.console/tools/.

Step2. Create a sample project

docfx init -q

This command generates a default project named docfx_project.

Step3. Build the website

docfx docfx_project\docfx.json --serve

Now you can view the generated website on http://localhost:8080.

Important

For macOS/Linux users: Use Mono version >= 5.10. Do NOT install Debian/Ubuntu-provided packages, since they typically do not provide all the packages required (for example, msbuild is missing). Once you have the Mono project's repositories added, the following command line can be used to install the prerequisites on Debian/Ubuntu: sudo apt-get install mono-runtime mono-devel msbuild.

For macOS users: DO NOT Install Mono from Homebrew, but rather from the Mono download page.

3. Use DocFX integrated with Visual Studio

Step1. Create a Class Library (.NET Framework) project

Step2. Right click on the project and select Manage NuGet Package

Step3. Search and install the docfx.console NuGet package. It adds itself to the build targets and adds the docfx.json configuration file along with other files.

Step4. Build the project, and a _site folder will be generated with the documentation.

Note

Possible warning:

  • Cache is corrupted: if your project targets multiple frameworks, you have to indicate one to be the main for the documentation, through the TargetFramework property in docfx.json:

    "metadata": [ { "src": "...", "dest": "...", "properties": { "TargetFramework": <one_of_your_framework> } }, ]

4. Use DocFX with a Build Server

4.1 Steps

DocFX can be used in a Continuous Integration (CI) environment.

Consider a typical scenario: We want to set up a job on a CI service (e.g. Azure Pipelines) to build documents automatically and publish to a website (e.g. GitHub Pages). We can achieve this with a script in a CI job with the following steps:

  1. clone repo
  2. choco install docfx
  3. docfx {docsetPath}, while you can change build.dest in docfx.json to set the output path
  4. push all the content in docsetPath/_site to gh-pages branch
Note

These steps give an overall impression of what to do. You can adjust them depending on actual scenario.

docfx-seed project provides a sample integrating with AppVeyor.

4.2 Set branch name

Most build systems do not checkout the branch that is being built, but use a detached head for the specific commit. DocFX needs the branch name to implement the View Source link in the API documentation.

Many build systems set an environment variable with the branch name. DocFX uses the following automatically:

Setting the environment variable DOCFX_SOURCE_BRANCH_NAME tells DocFX which branch name to use, if the CI service you use is not in the list above.

Note

Known issue in AppVeyor: Currently platform: Any CPU in appveyor.yml causes docfx metadata failure. https://github.com/dotnet/docfx/issues/1078

5. A seed project to play with DocFX

Here is a seed project: https://github.com/docascode/docfx-seed. It contains:

/ - The site’s root folder, which contains:

  • docfx.json - the configuration file that docfx depends upon.
  • index.md - used to create the Home page of the site
  • toc.yml – renders as the navigation menu bar, shown across the top of each page of the website.

/articles - Several conceptual .md files plus image files under /images. These Markdown files are published under the Articles section of the menu bar.

/restapi - REST API Swagger .json files, plus a toc.md that references them which are published under the REST API section of the menu bar.

/specs - Markdown "overwrite" files that are used to embellish content under the API Documentation menu, which is derived from the source code in /src. These are configured in docfx.json using the "overwrite": "specs/*.md" entry.

/src - A basic Visual Studio solution with 3 projects, which contain source code that defines the types published under the "API Documentation" section of the menu bar. The left-hand TOC shows the hierarchy of types defines, starting with the namespaces.

After running DocFx on the seed project files, additional folders will be created:

/_site - contains all of the site files generated by DocFx, including the resulting HTML/JSON/JS/Images files required by the web site.

/obj/api – contains the .yml files for .NET API classes/enums/interfaces contained under /src, plus a TOC.yml used for the "API Documentation" menu item.

Tip

It's good practice to separate files with different types into different folders.

6. Q&A

  1. Q: How do I quickly reference APIs from other APIs or conceptual files? A: Use @uid syntax.
  2. Q: What is uid and where do I find uid? A: Refer to Cross Reference section in DFM.
  3. Q: How do I quickly find uid in the website? A: In the generated website, hit F12 to view source, and look at the title of an API. You can find uid in data-uid attribute.