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  1. Examples

Node collapsing

This example shows how to use the nodeCollapsing transformation to collapse nodes in a graph.

ts
import Ogma, { NodeCollapsing } from '@linkurious/ogma';

interface NodeData {
  type: 'person' | 'company' | 'building';
  name: string;
}

interface EdgeData {
  type: 'employee_of' | 'works_at' | 'located_at';
}

const ogma = new Ogma<NodeData, EdgeData>({
  container: 'graph-container',
  options: {
    backgroundColor: '#f6f6f6'
  },
  graph: {
    nodes: [
      {
        id: 0,
        data: { type: 'person', name: 'John Smith' },
        attributes: { x: 0, y: 0 }
      },
      {
        id: 1,
        data: { type: 'company', name: 'Proton Brews' },
        attributes: { x: 30, y: -20 }
      },
      {
        id: 2,
        data: { type: 'building', name: '211 Golden Star Rd' },
        attributes: { x: 60, y: 0 }
      }
    ],
    edges: [
      { id: 0, source: 0, target: 1, data: { type: 'employee_of' } },
      { id: 1, source: 1, target: 2, data: { type: 'located_at' } }
    ]
  }
});

const ICONS = {
  person: '\uf007',
  company: '\uf155',
  building: '\uf1ad'
};

const COLORS = {
  person: 'orange',
  company: 'dodgerblue',
  building: 'green'
};

ogma.styles.addRule({
  nodeAttributes: {
    color: node => COLORS[node.getData('type')],
    text: node => node.getData('name'),
    icon: {
      content: node => ICONS[node.getData('type')],
      font: 'Font Awesome 5 Free'
    }
  },
  edgeAttributes: {
    shape: 'arrow',
    text: edge => edge.getData('type')
  }
});

const button = document.getElementById('btn') as HTMLButtonElement;
let transformation: NodeCollapsing<NodeData, EdgeData> | null = null;

const enableButton = () => {
  button.disabled = false;
  button.textContent = button.textContent === 'Collapse' ? 'Undo' : 'Collapse';
};

document.getElementById('btn')!.addEventListener('click', () => {
  if (transformation) {
    transformation.destroy(500).then(enableButton);
    button.disabled = true;
    transformation = null;
  } else {
    transformation = ogma.transformations.addNodeCollapsing({
      selector: node => node.getData('type') === 'company',
      edgeGenerator: hiddenNode => {
        console.log('generating edge from node', hiddenNode.getId());

        return { data: { type: 'works_at' } };
      },
      duration: 500
    });
    button.disabled = true;
    transformation.whenApplied().then(enableButton);
  }
});
html
<!doctype html>
<html>
  <head>
    <meta charset="utf-8" />
    <link
      href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/5.11.2/css/solid.min.css"
      rel="stylesheet"
    />

    <link type="text/css" rel="stylesheet" href="styles.css" />
  </head>
  <body>
    <div id="graph-container"></div>
    <div class="panel">
      <button id="btn">Collapse</button>
    </div>
    <script type="module" src="index.ts"></script>
  </body>
</html>
css
html,
body {
  font-family: 'Inter', sans-serif;
}

:root {
  --base-color: #4999f7;
  --active-color: var(--base-color);
  --gray: #d9d9d9;
  --white: #ffffff;
  --lighter-gray: #f4f4f4;
  --light-gray: #e6e6e6;
  --inactive-color: #cee5ff;
  --group-color: #525fe1;
  --group-inactive-color: #c2c8ff;
  --selection-color: #04ddcb;
  --darker-gray: #b6b6b6;
  --dark-gray: #555;
  --dark-color: #3a3535;
  --edge-color: var(--dark-color);
  --border-radius: 5px;
  --button-border-radius: var(--border-radius);
  --edge-inactive-color: var(--light-gray);
  --button-background-color: #ffffff;
  --shadow-color: rgba(0, 0, 0, 0.25);
  --shadow-hover-color: rgba(0, 0, 0, 0.5);
  --button-shadow: 0 0 4px var(--shadow-color);
  --button-shadow-hover: 0 0 4px var(--shadow-hover-color);
  --button-icon-color: #000000;
  --button-icon-hover-color: var(--active-color);
}

#graph-container {
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  position: absolute;
  margin: 0;
  overflow: hidden;
}

.ui {
  position: absolute;
  display: flex;
  flex-direction: column;
  gap: 0.5em;
}

#custom-group-btn {
  top: 40px;
}

.panel {
  background: var(--button-background-color);
  border-radius: var(--button-border-radius);
  box-shadow: var(--button-shadow);
  padding: 10px;
}

.panel {
  position: absolute;
  top: 20px;
  left: 20px;
}

.panel h2 {
  text-transform: uppercase;
  font-weight: 400;
  font-size: 14px;
  margin: 0;
}

.panel {
  margin-top: 1px;
  padding: 5px 10px;
  text-align: center;
}

.panel button {
  background: var(--button-background-color);
  border: none;
  border-radius: var(--button-border-radius);
  border-color: var(--shadow-color);
  padding: 5px 10px;
  cursor: pointer;
  width: 100%;
  color: var(--dark-gray);
  border: 1px solid var(--light-gray);
}

.panel button:hover {
  background: var(--lighter-gray);
  border: 1px solid var(--darker-gray);
}

.panel button[disabled] {
  color: var(--light-gray);
  border: 1px solid var(--light-gray);
  background-color: var(--lighter-gray);
}