🌊 React Flow

React Flow is a library for building node-based graphs. You can easily implement custom node types and it comes with plugins like a mini-map and graph controls. You can check out the examples or read the blog post to get started.

• Key Features
• Installation
• Usage
• Props
• Nodes
  • Props
  • Node Types / Custom Nodes
• Edges
  • Props
  • Edge Types / Custom Edges
• Helper Functions
• Plugins
  • Minimap
  • Controls
• Examples
• Development
• Testing

Key Features

• Easy to use: Seamless zooming & panning behaviour and single and multi-selections of elements
• Customizable: Different node and edge types and support for custom nodes and edges
• Fast rendering: only elements that are in the view port are displayed
• Utils: Snap-to-grid behaviour, background styles and graph helper functions
• Plugin system: Mini map and graph controls
• Reliable: Written in Typescript and tested with cypress

Installation

npm install react-flow-renderer

Usage

This is a very basic example of how to use react-flow. There are more advanced examples in the example folder.

import React from 'react';
import ReactFlow from 'react-flow-renderer';

const elements = [
  { id: '1', data: { label: 'Node 1' }, position: { x: 250, y: 5 } },
  { id: '2', data: { label: 'Node 2' }, position: { x: 100, y: 100 } },
  { id: 'e1-2', source: '1', target: '2', animated: true },
];

const graphStyles = { width: '100%', height: '100%' };

const BasicGraph = () => (
  <ReactFlow elements={elements} style={graphStyles} />
);

Props

• elements: array of nodes and edges (required)
• onElementClick: element click handler
• onElementsRemove: element remove handler
• onNodeDragStop: node drag stop handler
• onConnect: connect handler
• onLoad: editor load handler
• onMove: move handler
• nodeTypes: object with node types
• edgeTypes: object with edge types
• style: css style passed to the wrapper
• connectionLineType: connection line type = straight or bezier
• connectionLineStyle: connection style as svg attributes
• deleteKeyCode: default: 8 (delete)
• selectionKeyCode: default: 16 (shift)
• showBackground: default: true
• backgroundGap: gap size - default: 16
• backgroundColor: color of dots or lines - default: #eee
• backgroundType: background type = dots or lines - default: dots
• snapToGrid: default: false
• snapGrid: [x, y] array - default: [16, 16]
• onlyRenderVisibleNodes: default: true
• isInteractive: default: true. If the graph is not interactive you can't drag any nodes

Nodes

There are three different node types (default, input, output) you can use. You can also create custom nodes.

Node example: { id: '1', type: 'input', data: { label: 'Node 1' }, position: { x: 250, y: 5 } }

Props

• id: string (required)
• position: { x: number, y: number } (required)
• data: {} (required if you are using a standard type, otherwise depends on your implementation)
• type: 'input' | 'output' | 'default' or a custom one you implemented
• style: css properties
• targetPosition: 'left' | 'right' | 'top' | 'bottom' handle position - default: 'top'
• sourcePosition: 'left' | 'right' | 'top' | 'bottom' handle position - default: 'bottom'

Node Types / Custom Nodes

The standard node types are input, default and output. The default node types object looks like this:

{
  input: InputNode,
  default: DefaultNode,
  output: OutputNode
}

The keys represent the type names and the values are the node components that gets rendered. If you want to introduce a new node type you can pass a node types object like this:

nodeTypes={{
  special: MyCustomNode
}}

You can now use type special for a node. The default, input and output types will be still available except you overwrite one of them. You can find an example of how to implement a custom node in the custom node example.

Edges

There are three edge types (straight, default, step) you can use. The default type is default. You can also create custom edges.

Edge example: { id: 'e1-2', type: 'straight', source: '1', target: '2', animated: true }

Props

• id: string (required)
• source: string (required)
• target: string (required)
• type: 'input' | 'output' | 'default' or a custom one you implemented
• animated: boolean
• style: css properties

Edge Types / Custom Edges

The standard edge types are straight, default and step. The default edge types object looks like this:

{
  default: BezierEdge,
  straight: StraightEdge,
  step: StepEdge
}

The keys represents the type name and the value is the edge component. If you want to introduce a new edge type you can pass a edge types object like this:

edgeTypes={{
  special: MyCustomEdge
}}

You can now use type special for an edge. The straight, default and step types will be still available except you overwrite one of them.

Helper Functions

If you want to remove a node or connect two nodes with each other you need to pass a function to the onElementsRemove or the onConnect. In order to simplify this process we are exporting some helper functions so that you don't need to implement them by yourself:

import ReactFlow, { isNode, isEdge, removeElements, addEdge } from 'react-flow-renderer';

isEdge

isEdge = (element: Node | Edge): boolean

isNode

isNode = (element: Node | Edge): boolean

removeElements

removeElements = (elementsToRemove: Elements, elements: Elements): Elements

addEdge

addEdge = (edgeParams: Edge, elements: Elements): Elements

You can use these function to update your state as seen in this example.

Plugins

MiniMap

You can use the MiniMap plugin by passing it as a children of you graph:

import Graph, { MiniMap } from 'react-flow';

const GraphWithMiniMap = () => (
  <Graph
    elements={elements}
  >
    <MiniMap />
  </Graph>
);

Props

• nodeColor: string | function - if you pass a color as a string all nodes will get that color. If you pass a function you can return a color depending on the node.
• nodeBorderRadius: number
• maskColor: string
• style: css properties
• className: class name

Controls

The control panel contains a zoom-in, zoom-out and a fit-view button. You can use it by passing it as children to your graph:

import Graph, { Controls } from 'react-flow';

const GraphWithControls = () => (
  <Graph
    elements={elements}
  >
    <Controls />
  </Graph>
);

Props

• style: css properties
• className: class name

Examples

You can find all examples in the example folder or check out the live versions:

• rich
• basic
• empty
• inactive
• custom node

Development

If you want to contribute or develop some custom features the easiest way is to start the dev server:

npm run dev

This serves the content of the examples folder and watches changes inside the src folder. The examples are using the source of the src folder.

Testing

Testing is done with cypress. You can find all test in the integration/flow folder. In order to run the test you can do:

npm run test

Thanks!

Special thanks to Andy Lindemann for a lot of helpful contributions!