It offloads the library to an external service, keeping the JavaScript payload we need to serve from Rails smaller.Next, assuming the content is viewed in a JavaScript-enabled environment, we inject an iframe into the page, pointing the src attribute to the Viewscreen service.

We achieve this through a two-stage process-GitHub’s HTML pipeline and Viewscreen, our internal file rendering service.įirst, we add a filter to the HTML pipeline that looks for raw pre tags with the mermaid language designation and substitutes it with a template that works progressively, such that clients requesting content with embedded Mermaid in a non-JavaScript environment (such as an API request) will see the original Markdown code. When we encounter code blocks marked as mermaid, we generate an iframe that takes the raw Mermaid syntax and passes it to Mermaid.js, turning that code into a diagram in your local browser. The raw code block above will appear as this diagram in the rendered Markdown: Working with Knut and also the wider community at CommonMark, we’ve rolled out a change that will allow you to create graphs inline using Mermaid syntax, for example: Maintained by Knut Sveidqvist, it supports a bunch of different common diagram types for software projects, including flowcharts, UML, Git graphs, user journey diagrams, and even the dreaded Gantt chart. Mermaid is a JavaScript based diagramming and charting tool that takes Markdown-inspired text definitions and creates diagrams dynamically in the browser. We added support for embedding SVGs recently, but sometimes you want to keep your diagrams up to date with your docs and create something as easily as doing ASCII art, but a lot prettier.

A picture tells a thousand words, but up until now the only way to include pictures and diagrams in your Markdown files on GitHub has been to embed an image.

Notepad++ markdown theme