GitHub Discussion #2152

https://github.com/clientIO/joint/discussions/2152

by Roman Bruckner

HTML

<html>
<head>
    <link rel="stylesheet" type="text/css" href="https://cdnjs.cloudflare.com/ajax/libs/jointjs/3.7.0/joint.css" />
</head>
<body>
      <!-- content -->
      <div id="paper"></div>

      <!-- dependencies -->
        <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.4.1/jquery.js"></script>
        <script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.20/lodash.min.js"></script>
        <script src="https://cdnjs.cloudflare.com/ajax/libs/backbone.js/1.4.0/backbone.js"></script>
        <script src="https://cdnjs.cloudflare.com/ajax/libs/jointjs/3.7.0/joint.js"></script>
    
    </body>
</html>

JavaScript

var graph = new joint.dia.Graph({}, {
  cellNamespace: joint.shapes
});

const paper = new joint.dia.Paper({
  el: document.getElementById('paper'),
  width: 800,
  height: 900,
  model: graph,
  defaultConnectionPoint: {
    name: 'boundary',
    args: {
      selector: false
    }
  },
  cellViewNamespace: joint.shapes,
  gridSize: 10,
  async: true,
  sorting: joint.dia.Paper.sorting.APPROX,
  linkPinning: false
});


// Example

var el1 = new joint.shapes.uml.Class({
  position: {
    x: 10,
    y: 170
  },
  size: {
    width: 100,
    height: 90
  }
});

var el2 = el1.clone().position(300, 100);
var el3 = el1.clone().position(300, 400);

graph.resetCells([el1, el2, el3]);

paper.unfreeze();

let color = 'black';

el1.findView(paper).addTools(new joint.dia.ToolsView({
  tools: [
    new joint.linkTools.Connect({
      x: 'calc(w + 10)',
      y: 'calc(h/2)',
      magnet: (view) => { color = 'red'; return view.el },
      markup: joint.util.svg `
         <circle r="7" fill="red" />
      `
    }),
    new joint.linkTools.Connect({
      x: 'calc(w + 10)',
      y: 'calc(h/2 + 20)',
      magnet: (view) => { color = 'blue'; return view.el },
      markup: joint.util.svg `
         <circle r="7" fill="blue" />
      `
    }),
  ]
}));

paper.options.defaultLink = (elementView, magnet) => {
  return new joint.shapes.standard.Link({
    attrs: {
      line: {
        stroke: color
      }
    }
  });
}