Book Image

The Official Guide to Mermaid.js

By : Knut Sveidqvist, Ashish Jain
Book Image

The Official Guide to Mermaid.js

By: Knut Sveidqvist, Ashish Jain

Overview of this book

Mermaid is a JavaScript-based charting and diagramming tool that lets you represent diagrams using text and code, which simplifies the maintenance of complex diagrams. This is a great option for developers as they’re more familiar with code, rather than using special tools for generating diagrams. Besides, diagrams in code simplify maintenance and ensure that the code is supported by version control systems. In some cases, Mermaid makes refactoring support for name changes possible while also enabling team collaboration for review distribution and updates. Developers working with any system will be able to put their knowledge to work with this practical guide to using Mermaid for documentation. The book is also a great reference for looking up the syntax for specific diagrams when authoring diagrams. You’ll start by learning the importance of accurate and visual documentation. Next, the book introduces Mermaid and establishes how to use it to create effective documentation. By using different tools, editors, or a custom documentation platform, you’ll also understand how to use Mermaid syntax for various diagrams. Later chapters cover advanced configuration settings and theme options to manipulate your diagram as per your needs. By the end of this book, you’ll be well-versed with Mermaid diagrams and how they can be used in your workflows.
Table of Contents (19 chapters)
1
Section 1: Getting Started with Mermaid
7
Section 2: The Most Popular Diagrams
12
Section 3: Powerful Diagrams for the Advanced User

Subgraphs

In this section, you will learn how to structure your flowchart by separating subsets of shapes into a group visualized by a surrounding rectangle. In Mermaid, this grouping is called subgraphs, and although this is well outside the flowchart paradigm, it is very useful. If you are following a standardized flowchart modeling paradigm, you can use it as an alternative to the subroutine shape if you have space available. A more common use of subgraphs would be when you are using flowcharts to render something that is not really a flowchart but something else, such as the fictitious system overview shown in the following example:

Figure 6.50 – A flowchart showing an example of how subgraphs can be used for modeling

Figure 6.50 – A flowchart showing an example of how subgraphs can be used for modeling

Now that you have a fair idea of what subgraphs are, we will start looking at the syntax. When you add a subgraph, you start with the subgraph keyword, followed by the subgraph's ID. From now until the subgraph ends, any new...