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.

Installation

npm install --save react-digraph

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...).

All nodes and edges can have a type attribute set - nodes also support a subtype attribute. These can be passed to GraphView via the nodeTypes, nodeSubtypes, and edgeTypes props. GraphView will look up the corresponding SVG elements for the node's type/subtype and the edge's type and draw it accordingly.

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 from 'react-digraph'



const GraphConfig =  {
  NodeTypes: {
    empty: {
      typeText: "None",
      shapeId: "#empty",
      shape: (
        <symbol viewBox="0 0 100 100" id="empty" key="0">
          <circle cx="50" cy="50" r="45"></circle>
        </symbol>
      )
    }
  }, 
  NodeSubtypes: {}, 
  EdgeTypes: {
    emptyEdge: {
      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 EMPTY_TYPE = "empty"  // Text on empty nodes is positioned differently 
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}
                    emptyType={EMPTY_TYPE}
                    nodes={nodes}
                    edges={edges}
                    selected={selected}
                    nodeTypes={NodeTypes}
                    nodeSubtypes={NodeSubtypes}
                    edgeTypes={EdgeTypes}
                    getViewNode={this.getViewNode}
                    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": "empty"
    },
    {
      "id": 4,
      "title": "Node C",
      "x": 600.5757598876953,
      "y": 600.81818389892578,
      "type": "empty"
    }
  ],
  "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 example 

go to localhost:8000.

• 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
primary	string	false	Primary color.
light	string	false	Light color.
dark	string	false	Dark color.
style	object	false	Style prop for wrapper.
nodeKey	string	true	Key for D3 to update nodes(typ. UUID).
emptyType	string	true	'Default' node type.
nodes	array	true	Array of graph nodes.
edges	array	true	Array of graph edges.
readOnly	bool	false	Disables all graph editing interactions.
enableFocus	bool	false	Adds a 'focus' toggle state to GraphView.
selected	object	true	The currently selected graph entity.
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.
getViewNode	func	true	Node getter.
onSelectNode	func	true	Called when a node is selected.
onCreateNode	func	true	Called when a node is created.
onUpdateNode	func	true	Called when a node is moved.
canDeleteNode	func	false	Called before a node is deleted.
onDeleteNode	func	true	Called when a node is deleted.
onSelectEdge	func	true	Called when an edge is selected.
canCreateEdge	func	false	Called before an edge is created.
onCreateEdge	func	true	Called when an edge is created.
onSwapEdge	func	true	Called when an edge 'target' is swapped.
canDeleteEdge	func	false	Called before an edge is deleted.
onDeleteEdge	func	true	Called when an edge is deleted.

Notes

• To run the tests, you'll need to be using at least node v4.0 (for jsDom).