javascriptnode.jscytoscape.jscytoscape

Show/Hide labels on elements in the graph on button click


I have a Node application using Cytoscape v3.15.2. I have the styling set as follows

let cy = cytoscape({
            container: document.getElementById('graph-div'),
            style: [
                {
                    selector: 'node',
                    style: {
                        'label': 'data(id)',
                    }
               },
               {
                    selector: 'edge',
                    style: {
                        'label': (ele) => {
                            if(ele.data('type') === '1') return 'data(category1)';
                            if(ele.data('type') === '2') return 'data(category2)';
                            return value;
                        }
               }]
         }); 

Now, using a checkbox, I am trying to show/hide the labels on the elements. I have tried doing the following:

cy.elements().style("label","");

But this doesn't work. The same thing works when I pass a random string instead an empty string, something like this : cy.elements().style("label","random");. Doing this sets the labels of all elements in the graph to hidden. How can I do this?


Solution

  • You can manage showing/hiding labels by specifying a class in the stylesheet and then toggling it on button click as in the below example.

    var cy = window.cy = cytoscape({
      container: document.getElementById('cy'),
      layout: {name: 'grid', rows: 2},
      style: [{
          selector: '.hasLabel',
          css: {
            'label': (ele) => {
              if(ele.isNode()) return ele.data('id');
              if(ele.isEdge()) return ele.data('weight');         
            }
          }
        }
      ],
      elements: {
        nodes: [{
            data: {
              id: 'n0'          
            }
          },
          {
            data: {
              id: 'n1'
            }
          },
          {
            data: {
              id: 'n2'
            }
          },
          {
            data: {
              id: 'n3'
            }
          }
        ],
        edges: [{
            data: {
              id: 'n0n1',
              source: 'n0',
              target: 'n1',
              weight: 3
            }
          },
          {
            data: {
              id: 'n1n2',        
              source: 'n1',
              target: 'n2',
              weight: 5
            }
          },
          {
            data: {
              id: 'n2n3',        
              source: 'n2',
              target: 'n3',
              weight: 7
            }
          }
        ]
      }
    });
    
    document.getElementById("labelButton").addEventListener("click", function() {
      cy.elements().toggleClass('hasLabel');
    });
    body {
      font: 14px helvetica neue, helvetica, arial, sans-serif;
    }
    
    #button {
      z-index = 1000;
    }
    
    #cy {
      height: 95%;
      width: 95%;
      left: 0;
      top: 50;
      z-index = 900;
      position: absolute;
    }
    <html>
    
    <head>
      <meta charset=utf-8 />
      <meta name="viewport" content="user-scalable=no, initial-scale=1.0, minimum-scale=1.0, maximum-scale=1.0, minimal-ui">
      <script src="https://unpkg.com/cytoscape@3.10.0/dist/cytoscape.min.js">
      </script>
    </head>
    
    <body>
      <button id="labelButton" type="button">Show/Hide Labels</button>
      <div id="cy"></div>
    </body>
    
    </html>