Mermaid Graph React Component

A customizable React component that renders Mermaid diagrams with interactive nodes and edges. Designed to simplify embedding Mermaid.js graphs in your React applications.

Features

• Render Mermaid diagrams within React applications.
• Interactively click nodes and edges with customizable click handlers.
• Automatically updates when props change for dynamic graphs.

Installation

Install the package via npm:

npm install mermaid-graph 

Usage

Import the MermaidGraph component and use it in your React application:

import React from "react";
import { MermaidGraph } from "mermaid-graph";

export default function App() {
  const graphCode = `
    graph TD
    A[Start] --> B{Decision}
    B -->|edge| C[End]
    B -->|edge| D[Alternative End]
  `;

  const paths = [
    "A -> edge -> B -> edge -> D",
    "A -> edge -> B -> edge -> C"
  ];

  const handleNodeClick = (node: string) => {
    alert(`Node clicked: ${node}`);
  };

  const handleEdgeClick = (edge: string) => {
    alert(`Edge clicked: ${edge}`);
  };

  return (
    <MermaidGraph
      graphCode={graphCode}
      paths={paths}
      onNodeClick={handleNodeClick}
      onEdgeClick={handleEdgeClick}
    />
  );
}

Props

graphCode

•	Type: string
•	Required: true
•	Description: The Mermaid syntax string that defines the graph structure. 

paths

•	Type: string[]
•	Required: false
•	Description: An array of paths to style within the graph. Each path should use -> syntax to denote nodes and edges in sequence.

onNodeClick

•	Type: (node: string) => void
•	Required: false
•	Description: Callback function triggered when a node is clicked. Returns the ID of the clicked node.

onEdgeClick

•	Type: (edge: string) => void
•	Required: false
•	Description: Callback function triggered when an edge is clicked. Returns the ID of the clicked edge.

Example Graph Code

Here’s an example of a more complex Mermaid graph definition you can use with graphCode:

const graphcode =`
graph TD
S0((S0)) -->|0a| D1((D1))
D1((D1)) -->|1a| D3((D3))
D1((D1)) -->|1b| D2((D2))
D2((D2)) -->|2a| D5((D5))
D2((D2)) -->|2b| D6((D6))
D2((D2)) -->|2c| D4((D4))
D3((D3)) -->|3a| E5((E5))
D3((D3)) -->|3b| D7((D7))
D4((D4)) -->|4a| D8((D8))
D4((D4)) -->|4b| E6((E6))
`

Customizing with paths

You can highlight specific paths within your graph. For example:

const paths = [
  "S0 -> 0a -> D1 -> 1b -> D2 -> 2c -> D4 -> 4a -> D8",
  "S0 -> 0a -> D1 -> 1a -> D3 -> 3b -> D7"
];

Development

For local development:

1.	Clone the repository.
2.	Install dependencies with npm install.
3.	Run Storybook to preview changes in a development environment:

npx storybook init

npm run storybook

License

This project is licensed under the MIT License.

Explanation of Sections

• Installation: Basic npm/yarn installation commands.
• Usage: Example usage of the component, including the key props and example values.
• Props Documentation: Details each prop with type, requirement, and description.
• Customizing Paths: Shows how to use the paths prop for customization.
• Development Instructions: For contributors to preview and test changes locally.

This structure gives your users a clear guide on how to get started, use the component, and customize it to fit their needs.