dpvreony

Using Mermaid diagrams with Statiq.

TLDR: The sample repository is available at: https://github.com/dpvreony/article-statiq-mermaid.

Introduction

Mermaid is a toolset for producing diagrams using markdown notation. Statiq is a .NET based static website generation toolset. This article details a way to integrate the pair to display diagrams inside a statically generated website.

Getting started

  1. Create a .NET Core 3.1 (or NET5) console app project and add Statiq as a dependency.

    dotnet add package Statiq.Web
  2. Update the Program Entry point to utilize Statiq.

    using System.Threading.Tasks; using Statiq.App; using Statiq.Web; namespace StatiqMermaid.Website { public static class Program { public static async Task<int> Main(string[] args) { return await Bootstrapper .Factory .CreateWeb(args) .RunAsync(); } } }
  3. Mermaid has a NodeJS Command Line Interface tool which can be installed as an development dependency. You will need a recent version of NodeJS installed then you can install the CLI:

    npm install @mermaid-js/mermaid-cli -D

You're now ready to get running with Mermaid

Preparing a Mermaid Markdown file

This sample makes use of the flowchart example from the Mermaid website, where you can find more samples and instructions on the markdown notation.
  1. Create a folder structure in your console app project of "input\img\mermaid"
  2. Add a text file to the mermaid folder with an .mmd file extension. For example flowchart.mmd
  3. Add the following markdown notation to the file:

    graph TD; A-->B; A-->C; B-->D; C-->D;

Transforming the Mermaid diagram to an image

You may want to consider changing your .gitignore to include the following lines: src/StatiqMermaid.Website/input/img/mermaid/*.svg
src/StatiqMermaid.Website/input/img/mermaid/*.png
src/StatiqMermaid.Website/output
  1. In the folder containing your solution create a batch file along the lines of build-mermaid.cmd
  2. Add the following commands:

    pushd StatiqMermaid.Website\input\img\mermaid ..\..\..\node_modules\.bin\mmdc -i flowchart.mmd -o flowchart.svg popd

Building Statiq and Viewing the result

The following script can sometimes error in Kestrel with the message "An attempt was made to access a socket in a way forbidden" if the port it is trying to use has been reserved by the operating system. Try changing the port number. For more detailed information check out https://ardalis.com/attempt-made-to-access-socket/
  1. In the folder containing your solution create a batch file along the lines of run-testserver.cmd
  2. Add the following command:

    dotnet run --project StatiqMermaid.Website -- preview --port 30080
Screenshot of a webpage containing a diagram generated from Mermaid notation

Going further

Now you have the basic flow you can consider:
  1. Playing with more diagrams and different image output styles and file formats.
  2. Using a foreach loop in a batch file or powershell script to transfrom multiple markdown files.
  3. Using a shellexecute stage during your Statiq Console app build phase.
  4. Setting up a CI\CD flow to automate the build and deploy.

References

  • Github mermaid-cli https://github.com/mermaid-js/mermaid-cli
  • Mermaid Flowchart Sameple https://mermaid-js.github.io/mermaid/#/flowchart?id=flowcharts-basic-syntax
  • MARTIN BJÖRKSTRÖM: I ported my blog to Statiq https://martinbjorkstrom.com/posts/2020-04-20-i-ported-my-blog-to-statiq
Article Status Released
Article Version 1.2
First Written 2021-03-27
Last Revision 2021-04-18
Next Review 2022-04-18
License MIT