Custom Router In Grid

by Roman Bruckner

HTML

<html>
<head>
    <link rel="stylesheet" type="text/css" href="https://cdnjs.cloudflare.com/ajax/libs/jointjs/3.5.5/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/3.5.5/joint.js"></script>
    
    </body>
</html>

JavaScript

const columnCount = 5;
const count = 30;
const elWidth = 80;
const elHeight = 100;
const gapX = 100;
const gapY = 50;

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

const paper = new joint.dia.Paper({
    el: document.getElementById('paper'),
    width: 1000,
    height: 600,
    model: graph,
    cellViewNamespace: joint.shapes,
    defaultConnectionPoint: {
        name: 'boundary',
        args: {
            extrapolate: true,
            sticky: true,
        },
    },
    snapLinks: true,
    linkPinning: false,
    interactive: { elementMove: false },
    defaultLink: () => new joint.shapes.standard.Link(),
    validateConnection: function(sv, sm, tv, tm) {
        if (sv.model.get('column') >= tv.model.get('column')) return false;
        if (tv.findAttribute('port-group', tm) === 'out') return false;
        return true;
    },
    defaultRouter: (_, opt, linkView) => {
        const sourceView = linkView.getEndView('source');
        const targetView = linkView.getEndView('target');
        if (!sourceView || !targetView) return [];
        const source = sourceView.model;
        const target = targetView.model;
        const sourceColumn = source.get('column');
        const targetColumn = target.get('column');
        const sourceRow = source.get('row');
        const targetRow = target.get('row');
        const sourceAnchor = linkView.getEndAnchor('source');
        const targetAnchor = linkView.getEndAnchor('target');

        const neighbors = sourceColumn !== targetColumn - 1;
        const fx = neighbors ? (sourceRow > targetRow ? -1 : 1) : 0;
        const fx2 = (sourceRow === targetRow ? -1 : 1)
        const fy = (sourceColumn > targetColumn ? -1 : 1);

        // a formula to calculate the number of points to be added to the path
        // to avoid overlapping of the links
        const shift = (sourceAnchor.y - source.position().y) / elHeight * 20;

        const p1 = {
            x: sourceColumn * (gapX +...