react-digraph

react-digraph

Overview

A React component which makes it easy to create a directed graph editor without implementing any of the SVG drawing or event handling logic.

Important v5.0.0 Information

Version 5.0.0 is a breaking change to some of the API interfaces. Many of the component attributes are the same, and the data format is the same, but there have been some necessary changes to improve the API, make the component faster, and add new features. Many changes will be listed below in the deprecation notes section. If you notice a problem, please use the ^4.0.0 versions of the package and refer to the legacy documentation in the v4.x.x git branch.

Installation

npm install --save react-digraph

If you don't have the following peerDependenies, make sure to install them:

npm install --save react react-dom

Usage

The default export is a component called GraphView; it provides a multitude of hooks for various graph editing operations and a set of controls for zooming. Typically, it should be wrapped in a higher order component that supplies various callbacks (onCreateNode, onCreateEdge etc...).

GraphView expects several properties to exist on your nodes and edges. If these types conflict with existing properties on your data, you must transform your data to re-key these properties under different names and to add the expected properties. All nodes and edges can have a type attribute set - nodes also support a subtype attribute. For a full description of node and edge properties, see the sections for INode and IEdge below.

Configuration for nodes and edges can be passed to GraphView via the nodeTypes, nodeSubtypes, and edgeTypes props. Custom SVG elements can be defined here for the node's type/subtype and the edge's type.

It is often convenient to combine these types into a configuration object that can be referred to elsewhere in the application and used to associate events fired from nodes/edges in the GraphView with other actions in the application. Here is an abbreviated example:

import {
  GraphView, // required
  Edge, // optional
  type IEdge, // optional
  Node, // optional
  type INode, // optional
  type LayoutEngineType, // required to change the layoutEngineType, otherwise optional
  BwdlTransformer, // optional, Example JSON transformer
  GraphUtils // optional, useful utility functions
} from 'react-digraph';

const GraphConfig =  {
  NodeTypes: {
    empty: { // required to show empty nodes
      typeText: "None",
      shapeId: "#empty", // relates to the type property of a node
      shape: (
        <symbol viewBox="0 0 100 100" id="empty" key="0">
          <circle cx="50" cy="50" r="45"></circle>
        </symbol>
      )
    },
    custom: { // required to show empty nodes
      typeText: "Custom",
      shapeId: "#custom", // relates to the type property of a node
      shape: (
        <symbol viewBox="0 0 50 25" id="custom" key="0">
          <ellipse cx="50" cy="25" rx="50" ry="25"></ellipse>
        </symbol>
      )
    }
  },
  NodeSubtypes: {},
  EdgeTypes: {
    emptyEdge: {  // required to show empty edges
      shapeId: "#emptyEdge",
      shape: (
        <symbol viewBox="0 0 50 50" id="emptyEdge" key="0">
          <circle cx="25" cy="25" r="8" fill="currentColor"> </circle>
        </symbol>
      )
    }
  }
}

const NODE_KEY = "id"       // Allows D3 to correctly update DOM

class Graph extends Component {

  constructor(props) {
    super(props);

    this.state = {
      graph: sample,
      selected: {}
    }
  }

  /* Define custom graph editing methods here */

  render() {
    const nodes = this.state.graph.nodes;
    const edges = this.state.graph.edges;
    const selected = this.state.selected;

    const NodeTypes = GraphConfig.NodeTypes;
    const NodeSubtypes = GraphConfig.NodeSubtypes;
    const EdgeTypes = GraphConfig.EdgeTypes;

    return (
      <div id='graph' style={styles.graph}>

        <GraphView  ref='GraphView'
                    nodeKey={NODE_KEY}
                    nodes={nodes}
                    edges={edges}
                    selected={selected}
                    nodeTypes={NodeTypes}
                    nodeSubtypes={NodeSubtypes}
                    edgeTypes={EdgeTypes}
                    onSelectNode={this.onSelectNode}
                    onCreateNode={this.onCreateNode}
                    onUpdateNode={this.onUpdateNode}
                    onDeleteNode={this.onDeleteNode}
                    onSelectEdge={this.onSelectEdge}
                    onCreateEdge={this.onCreateEdge}
                    onSwapEdge={this.onSwapEdge}
                    onDeleteEdge={this.onDeleteEdge}/>
      </div>
    );
  }

}

A typical graph that would be stored in the Graph component's state looks something like this:

{
  "nodes": [
    {
      "id": 1,
      "title": "Node A",
      "x": 258.3976135253906,
      "y": 331.9783248901367,
      "type": "empty"
    },
    {
      "id": 2,
      "title": "Node B",
      "x": 593.9393920898438,
      "y": 260.6060791015625,
      "type": "empty"
    },
    {
      "id": 3,
      "title": "Node C",
      "x": 237.5757598876953,
      "y": 61.81818389892578,
      "type": "custom"
    },
    {
      "id": 4,
      "title": "Node C",
      "x": 600.5757598876953,
      "y": 600.81818389892578,
      "type": "custom"
    }
  ],
  "edges": [
    {
      "source": 1,
      "target": 2,
      "type": "emptyEdge"
    },
    {
      "source": 2,
      "target": 4,
      "type": "emptyEdge"
    }
  ]
}

For a detailed example, check out src/examples/graph.js. To run the example:

npm install
npm run serve

A webpage will open in your default browser automatically.

• To add nodes, hold shift and click on the grid.
• To add edges, hold shift and click/drag to between nodes.
• To delete a node or edge, click on it and press delete.
• Click and drag nodes to change their position.

All props are detailed below.

Props

Prop	Type	Required	Notes
nodeKey	string	true	Key for D3 to update nodes(typ. UUID).
nodes	Array<INode>	true	Array of graph nodes.
edges	Array<IEdge>	true	Array of graph edges.
allowMultiselect	boolean	false	Use Ctrl-Shift-LeftMouse to draw a multiple selection box
selected	object	true	The currently selected graph entity.
selectedNodes	Map<string, INode>	false	If allowMultiselect is true, this should be the currently selected array of nodes.
selectedEdges	Map<string, IEdge>	false	If allowMultiselect is true, this should be the currently selected array of edges.
nodeTypes	object	true	Config object of available node types.
nodeSubtypes	object	true	Config object of available node subtypes.
edgeTypes	object	true	Config object of available edge types.
onSelect	func	false	Called when nodes are selected when allowMultiselect is true. Is passed an object with nodes and edges included.
onSelectNode	func	false	Called when a node is selected.
onCreateNode	func	true	Called when a node is created.
onContextMenu	func	true	Called when contextmenu event triggered.
onUpdateNode	func	true	Called when a node is moved.
onDeleteNode	func	true	Called when a node is deleted. This function should also delete connected edges.
onSelectEdge	func	true	Called when an edge is selected.
onCreateEdge	func	true	Called when an edge is created.
onSwapEdge	func	true	Called when an edge 'target' is swapped.
onDeleteEdge	func	true	Called when an edge is deleted. This function is not called when multiple nodes and edges are selected using the allowMultiselect feature. Only when a single edge is selected.
onBackgroundClick	func	false	Called when the background is clicked.
onArrowClicked	func	false	Called when the arrow head is clicked.
onUndo	func	false	A function called when Ctrl-Z is activated. React-digraph does not keep track of actions, this must be implemented in the client website.
onCopySelected	func	false	A function called when Ctrl-C is activated. React-digraph does not keep track of copied nodes or edges, the this must be implemented in the client website.
onPasteSelected	func	false	A function called when Ctrl-V is activated. React-digraph does not keep track of copied nodes or edges, the this must be implemented in the client website.
canDeleteNode	func	false	Called before a node is deleted.
canCreateEdge	func	false	Called before an edge is created.
canDeleteEdge	func	false	Called before an edge is deleted.
canSwapEdge	func	false	Called before an edge 'target' is swapped.
afterRenderEdge	func	false	Called after an edge is rendered.
renderNode	func	false	Called to render node geometry.
renderNodeText	func	false	Called to render the node text
renderDefs	func	false	Called to render SVG definitions.
renderBackground	func	false	Called to render SVG background.
readOnly	bool	false	Disables all graph editing interactions.
disableBackspace	bool	false	Disables using backspace to delete the selected node.
maxTitleChars	number	false	Truncates node title characters.
gridSize	number	false	Overall grid size.
gridSpacing	number	false	Grid spacing.
gridDotSize	number	false	Grid dot size.
minZoom	number	false	Minimum zoom percentage.
maxZoom	number	false	Maximum zoom percentage.
nodeSize	number	false	Node bbox size.
edgeHandleSize	number	false	Edge handle size.
edgeArrowSize	number	false	Edge arrow size in pixels. Default 8. Set to 0 to hide arrow.
zoomDelay	number	false	Delay before zoom occurs.
zoomDur	number	false	Duration of zoom transition.
showGraphControls	boolean	false	Whether to show zoom controls.
layoutEngineType	typeof LayoutEngineType	false	Uses a pre-programmed layout engine, such as 'SnapToGrid'
rotateEdgeHandle	boolean	false	Whether to rotate edge handle with edge when a node is moved
centerNodeOnMove	boolean	false	Whether the node should be centered on cursor when moving a node
initialBBox	typeof IBBox	false	If specified, initial render graph using the given bounding box
graphConfig	object	false	dagre graph setting configuration, which will override layout engine graph configuration - only apply to 'HorizontalTree'
nodeSizeOverridesAllowed	boolean	false	Flag to toggle sizeOverride in nodes - only apply to 'HorizontalTree'
nodeLocationOverrides	object	false	Nodes location overrides object - only apply to 'HorizontalTree'

onCreateNode

You have access to d3 mouse event in onCreateNode function.

  onCreateNode = (x, y, mouseEvent) => {
    // we can get the exact mouse position when click happens with this line
    const {pageX, pageY} = mouseEvent;
    // rest of the code for adding a new node ...
  };

Prop Types:

See prop types in the typings folder.

INode

Prop	Type	Required	Notes
anyIDKey	string	true	An id or key for nodes, same as the nodeKey prop
title	string	true	Used in edges and to render the node text.
x	number	false	X coordinate of the node.
y	number	false	Y coordinate of the node.
type	string	false	Node type, for displaying a custom SVG shape.
subtype	string	false	Node subtype, for displaying a custom SVG shape.

title

The title attribute is used for the IDs in the SVG nodes in the graph. Because Element.querySelector() is used to locate graph entities, please ensure that all titles are properly escaped (for example, with CSS.escape()).

IEdge

Prop	Type	Required	Notes
source	string	true	The title of the parent node.
target	string	true	The title of the child node.
type	string	false	Edge type, for displaying a custom SVG shape.
handleText	string	false	Text to render on the edge.
handleTooltipText	string	false	Used to render the SVG title element.
label_from	string	false	Text to render along the edge with label_to.
label_to	string	false	Text to render along the edge with label_from.

Imperative API

You can call these methods on the GraphView class using a ref.

Method	Type	Notes
panToNode	(id: string, zoom?: boolean) => void	Center the node given by id within the viewport, optionally zoom in to fit it.
panToEdge	(source: string, target: string, zoom?: boolean) => void	Center the edge between source and target node IDs within the viewport, optionally zoom in to fit it.

Deprecation Notes

Prop	Type	Required	Notes
emptyType	string	true	'Default' node type.
getViewNode	func	true	Node getter.
renderEdge	func	false	Called to render edge geometry.
enableFocus	bool	false	Adds a 'focus' toggle state to GraphView.
transitionTime	number	false	Fade-in/Fade-out time.
primary	string	false	Primary color.
light	string	false	Light color.
dark	string	false	Dark color.
style	object	false	Style prop for wrapper.
gridDot	number	false	Grid dot size.
graphControls	boolean	true	Whether to show zoom controls.