cytoscape-dagre

Description

The Dagre layout for DAGs and trees for Cytoscape.js (demo)

The dagre layout organises the graph using a DAG (directed acyclic graph) system, written by Chris Pettitt. It is especially suitable for DAGs and trees. For more information, please refer to Dagre's documentation.

Dependencies

• Cytoscape.js ^3.2.0
• Dagre ^0.8.2

Usage instructions

Download the library:

• via npm: npm install cytoscape-dagre,
• via bower: bower install cytoscape-dagre, or
• via direct download in the repository (probably from a tag).

Import the library as appropriate for your project:

ES import:

import cytoscape from 'cytoscape';
import dagre from 'cytoscape-dagre';

cytoscape.use( dagre );

CommonJS require:

let cytoscape = require('cytoscape');
let dagre = require('cytoscape-dagre');

cytoscape.use( dagre ); // register extension

AMD:

require(['cytoscape', 'cytoscape-dagre'], function( cytoscape, dagre ){
  dagre( cytoscape ); // register extension
});

Plain HTML/JS has the extension registered for you automatically, because no require() is needed.

API

Call the layout, e.g. cy.layout({ name: 'dagre', ... }).run(), with options:

var defaults = {
  // dagre algo options, uses default value on undefined
  nodeSep: undefined, // the separation between adjacent nodes in the same rank
  edgeSep: undefined, // the separation between adjacent edges in the same rank
  rankSep: undefined, // the separation between each rank in the layout
  rankDir: undefined, // 'TB' for top to bottom flow, 'LR' for left to right,
  align: undefined,  // alignment for rank nodes. Can be 'UL', 'UR', 'DL', or 'DR', where U = up, D = down, L = left, and R = right
  acyclicer: undefined, // If set to 'greedy', uses a greedy heuristic for finding a feedback arc set for a graph.
                        // A feedback arc set is a set of edges that can be removed to make a graph acyclic.
  ranker: undefined, // Type of algorithm to assign a rank to each node in the input graph. Possible values: 'network-simplex', 'tight-tree' or 'longest-path'
  minLen: function( edge ){ return 1; }, // number of ranks to keep between the source and target of the edge
  edgeWeight: function( edge ){ return 1; }, // higher weight edges are generally made shorter and straighter than lower weight edges

  // general layout options
  fit: true, // whether to fit to viewport
  padding: 30, // fit padding
  spacingFactor: undefined, // Applies a multiplicative factor (>0) to expand or compress the overall area that the nodes take up
  nodeDimensionsIncludeLabels: false, // whether labels should be included in determining the space used by a node
  animate: false, // whether to transition the node positions
  animateFilter: function( node, i ){ return true; }, // whether to animate specific nodes when animation is on; non-animated nodes immediately go to their final positions
  animationDuration: 500, // duration of animation in ms if enabled
  animationEasing: undefined, // easing of animation if enabled
  boundingBox: undefined, // constrain layout bounds; { x1, y1, x2, y2 } or { x1, y1, w, h }
  transform: function( node, pos ){ return pos; }, // a function that applies a transform to the final node position
  ready: function(){}, // on layoutready
  sort: undefined, // a sorting function to order the nodes and edges; e.g. function(a, b){ return a.data('weight') - b.data('weight') }
                   // because cytoscape dagre creates a directed graph, and directed graphs use the node order as a tie breaker when
                   // defining the topology of a graph, this sort function can help ensure the correct order of the nodes/edges.
                   // this feature is most useful when adding and removing the same nodes and edges multiple times in a graph.
  stop: function(){} // on layoutstop
};

Build targets

• npm run test : Run Mocha tests in ./test
• npm run build : Build ./src/** into cytoscape-dagre.js
• npm run watch : Automatically build on changes with live reloading (N.b. you must already have an HTTP server running)
• npm run dev : Automatically build on changes with live reloading with webpack dev server
• npm run lint : Run eslint on the source

N.b. all builds use babel, so modern ES features can be used in the src.

Publishing instructions

This project is set up to automatically be published to npm and bower. To publish:

1. Build the extension : npm run build:release
2. Commit the build : git commit -am "Build for release"
3. Bump the version number and tag: npm version major|minor|patch
4. Push to origin: git push && git push --tags
5. Publish to npm: npm publish .
6. If publishing to bower for the first time, you'll need to run bower register cytoscape-dagre https://github.com/cytoscape/cytoscape.js-dagre.git
7. Make a new release for Zenodo.