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

Customizing Theming Variables

In this section, we will focus on using theme variables to modify the look of an ER diagram. In this section, we will continue from where Chapter 5, Changing Themes and Making Mermaid Look Good, left off and learn about overriding the theme variables of an ER diagram.

Let's imagine that there are some aspects of your ER diagram that you want to change, such as the background color from the default color that was assigned by the theme. Here, you will learn about such theme variables and how to override them.

To demonstrate the use of such variables, we will start by looking at a vanilla ER diagram with a neutral theme and override them one by one to see the impact of the override on the diagram. The following code snippet is for an ER diagram with the neutral theme enabled:

%%{init:{"theme":"neutral"}}%%
erDiagram
  Company ||--o{ Employees : hires

The following image shows how this code snippet is rendered...