d3 - Search tree and highlight node and path for d3 v5

Question

I have been using Patrick Brockmann's CollapsibleTree Search with d3 v3.5. The search function populates a Select2 with leaves of the tree which can then be used to find a leaf and highlight the path to the leaf node in red.

I am now trying to get it to work with d3 v5 .

I can get the Select2 populated OK, but selecting a leaf in the Select2 open all leaves in the tree and no highlighting occurs when making the selection.

Note : If you collapse the tree, then expand manually you can see the highlighted nodes and path... So sort of working, but I presume not collapsing nodes where d.class !== "found"

function collapseAllNotFound( d ) {
        if ( d.children ) {
            if ( d.class !== "found" ) {
                d._children = d.children;
                d._children.forEach( collapseAllNotFound );
                d.children = null;
            } else
                d.children.forEach( collapseAllNotFound );
        }
    }

See fiddle

Full code:

   $("#search").select2("val", "");

var treeData =
  {
    "name": "Top Level",
    "children": [
      { 
        "name": "A",
        "children": [
          { "name": "A1", "type": "unit" },
          { "name": "A2", "type": "unit" },
          { "name": "A3", "type": "unit" },
          { "name": "A4", "type": "unit" },
          { "name": "A5", "type": "unit" },
          { "name": "A6", "type": "unit" },
        ]
      },
      { "name": "B",
        "children": [
          { "name": "B1", "type": "unit" },
          { "name": "B2", "type": "unit" },
          { "name": "B3", "type": "unit" },
          { "name": "B4", "type": "unit" },
          { "name": "B5", "type": "unit" },
          { "name": "B6", "type": "unit" },
        ]
      }
    ]
  };

      var colourScale = d3.scaleOrdinal()
        .domain(["Top Level", "A", "B"])
        .range(["#abacab", "#53e28c", "#4b80fa"]);

  function select2DataCollectName( d ) {
                if ( d.children )
                    d.children.forEach( select2DataCollectName );
                else if ( d._children )
                    d._children.forEach( select2DataCollectName );
                if ( !d.children && d.data.type == 'unit' ) select2Data.push( d.data.name );
            }

            //===============================================
            function searchTree( d ) {
                if ( d.children )
                    d.children.forEach( searchTree );
                else if ( d._children )
                    d._children.forEach( searchTree );
                var searchFieldValue = eval( searchField );
                if ( searchFieldValue && searchFieldValue.toLowerCase().match( searchText.toLowerCase() ) ) {
                    // Walk parent chain
                    var ancestors = [];
                    var parent = d;
                    while ( typeof ( parent ) !== "undefined" ) {
                        ancestors.push( parent );
                        //console.log(parent);
                        parent.class = "found";
                        parent = parent.parent;
                    }
                    console.log(ancestors);
                }
            }

            //===============================================
            function clearAll( d ) {
                d.class = "";
                if ( d.children )
                    d.children.forEach( clearAll );
                else if ( d._children )
                    d._children.forEach( clearAll );
            }
            //===============================================
            function collapse( d ) {

                if ( d.children ) {
                    d._children = d.children;
                    //set the parent object in all the children
                    d._children.forEach( function ( d1 ) {
                        d1.parent = d;
                        collapse( d1 );
                    } );
                    d.children = null;
                }
            }
            //===============================================
            function collapseAllNotFound( d ) {
                if ( d.children ) {

                    if ( d.class !== "found" ) {
                        d._children = d.children;
                        d._children.forEach( collapseAllNotFound );
                        d.children = null;
                    } else
                        d.children.forEach( collapseAllNotFound );
                }
            }
            //===============================================
            function expandAll( d ) {
                if ( d._children ) {
                    d.children = d._children;
                    d.children.forEach( expandAll );
                    d._children = null;
                } else if ( d.children )
                    d.children.forEach( expandAll );
            }

            //===============================================
            // Toggle children on click.
            function toggle( d ) {
                if ( d.children ) {
                    d._children = d.children;
                    d.children = null;
                } else {
                    d.children = d._children;
                    d._children = null;
                }
                clearAll( root );
                update( d );
                $( "#search" ).select2( "val", "" );
            }

            //===============================================
            $( "#search" ).on( "select2-selecting", function ( e ) {
                clearAll( root );
                expandAll( root );
                update( root );
                searchField = "d.data.name";
                searchText = e.object.text;
                searchTree( root );
                root.children.forEach( collapseAllNotFound );
                update( root );
            } )

       function findParent(datum) {
            if (datum.depth < 2) {
                return datum.data.name
            } else {
                return findParent(datum.parent)
            }
        }

        function findParentLinks(datum) {
            if (datum.depth < 2) {
                return datum.data.name
            } else {
                return findParent(datum.parent)
            }
        }

// Set the dimensions and margins of the diagram
var margin = {top: 20, right: 90, bottom: 30, left: 90},
    width = 960 - margin.left - margin.right,
    height = 500 - margin.top - margin.bottom;

// append the svg object to the body of the page
// appends a 'group' element to 'svg'
// moves the 'group' element to the top left margin
var svg = d3.select("body").append("svg")
    .attr("width", width + margin.right + margin.left)
    .attr("height", height + margin.top + margin.bottom)
  .append("g")
    .attr("transform", "translate("
          + margin.left + "," + margin.top + ")");

var i = 0,
    duration = 750,
    root;

// declares a tree layout and assigns the size
var treemap = d3.tree().size([height, width]);

// Assigns parent, children, height, depth
root = d3.hierarchy(treeData, function(d) { return d.children; });
root.x0 = height / 2;
root.y0 = 0;

// Collapse after the second level
root.children.forEach(collapse);

update(root);

select2Data = [];
                select2DataCollectName( root );
                select2DataObject = [];
                select2Data.sort( function ( a, b ) {
                        if ( a > b ) return 1; // sort
                        if ( a < b ) return -1;
                        return 0;
                    } )
                    .filter( function ( item, i, ar ) {
                        return ar.indexOf( item ) === i;
                    } ) // remove duplicate items
                    .filter( function ( item, i, ar ) {
                        select2DataObject.push( {
                            "id": i,
                            "text": item
                        } );
                    } );
                $( "#search" ).select2( {
                    placeholder: "Select a Leaf...",
                    data: select2DataObject,
                    containerCssClass: "search"
                } );

// Collapse the node and all it's children
function collapse(d) {
  if(d.children) {
    d._children = d.children
    d._children.forEach(collapse)
    d.children = null
  }
}

function update(source) {

  // Assigns the x and y position for the nodes
  var treeData = treemap(root);

  // Compute the new tree layout.
  var nodes = treeData.descendants(),
      links = treeData.descendants().slice(1);

  // Normalize for fixed-depth.
  nodes.forEach(function(d){ d.y = d.depth * 180});

  // ****************** Nodes section ***************************

  // Update the nodes...
  var node = svg.selectAll('g.node')
      .data(nodes, function(d) {return d.id || (d.id = ++i); });

  // Enter any new modes at the parent's previous position.
  var nodeEnter = node.enter().append('g')
      .attr('class', 'node')
      .attr("transform", function(d) {
        return "translate(" + source.y0 + "," + source.x0 + ")";
    })
    .on('click', click);

  // Add Circle for the nodes
  nodeEnter.append('circle')
      .attr('class', 'node')
      .attr('r', 1e-6)
      .style("fill", function(d) {
          return d._children ? "lightsteelblue" : "#fff";
      });

  // Add labels for the nodes
  nodeEnter.append('text')
      .attr("dy", ".35em")
      .attr("x", function(d) {
          return d.children || d._children ? -13 : 13;
      })
      .attr("text-anchor", function(d) {
          return d.children || d._children ? "end" : "start";
      })
      .text(function(d) { return d.data.name; });

  // UPDATE
  var nodeUpdate = nodeEnter.merge(node);

  // Transition to the proper position for the node
  nodeUpdate.transition()
    .duration(duration)
    .attr("transform", function(d) { 
        return "translate(" + d.y + "," + d.x + ")";
     });

  // Update the node attributes and style
 nodeUpdate.select('circle.node')
            .attr('r', 6)
            .attr("fill-opacity", "0.7")
            .attr("stroke-opacity", "1")
            .style("fill", function(d) {
                if (d.class === "found") {
                    return "#ff4136"; //red
                } else {
                    return (typeof d._children !== 'undefined') ? (colourScale(findParent(d))) : '#FFF';
                }
            })
            .style("stroke", function(d) {
                if (d.class === "found") {
                    return "#ff4136"; //red
                } else {
                    return colourScale(findParent(d));
                }
            });


  // Remove any exiting nodes
  var nodeExit = node.exit().transition()
      .duration(duration)
      .attr("transform", function(d) {
          return "translate(" + source.y + "," + source.x + ")";
      })
      .remove();

  // On exit reduce the node circles size to 0
  nodeExit.select('circle')
    .attr('r', 1e-6);

  // On exit reduce the opacity of text labels
  nodeExit.select('text')
    .style('fill-opacity', 1e-6);

  // ****************** links section ***************************

  // Update the links...
  var link = svg.selectAll('path.link')
      .data(links, function(d) { return d.id; });

  // Enter any new links at the parent's previous position.
  var linkEnter = link.enter().insert('path', "g")
      .attr("class", "link")
      .attr('d', function(d){
        var o = {x: source.x0, y: source.y0}
        return diagonal(o, o)
      });

  // UPDATE
  var linkUpdate = linkEnter.merge(link);

  // Transition back to the parent element position
  linkUpdate.transition()
            .duration(duration)
            .attr('d', function(d) {
                return diagonal(d, d.parent)
            })
            .style( "stroke", function ( d ) {
                        if ( d.class === "found" ) {
                            return "#ff4136";
                        } else {
                            return colourScale( findParentLinks( d ) );
                        }
                    } );

  // Remove any exiting links
  var linkExit = link.exit().transition()
      .duration(duration)
      .attr('d', function(d) {
        var o = {x: source.x, y: source.y}
        return diagonal(o, o)
      })
      .remove();

  // Store the old positions for transition.
  nodes.forEach(function(d){
    d.x0 = d.x;
    d.y0 = d.y;
  });

  // Creates a curved (diagonal) path from parent to the child nodes
  function diagonal(s, d) {

    path = `M ${s.y} ${s.x}
            C ${(s.y + d.y) / 2} ${s.x},
              ${(s.y + d.y) / 2} ${d.x},
              ${d.y} ${d.x}`

    return path
  }

  // Toggle children on click.
  function click(d) {
    if (d.children) {
        d._children = d.children;
        d.children = null;
      } else {
        d.children = d._children;
        d._children = null;
      }
    update(d);
  }
}

Answer 1

It seems that function searchTree() is not working properly. In particular the root node has no ancestors but you don't control that parent !== null on while loop. Adding this control everything seems to work properly. The correct function becomes:

function searchTree( d ) {
                    if ( d.children )
                        d.children.forEach( searchTree );
                    else if ( d._children )
                        d._children.forEach( searchTree );
                    var searchFieldValue = eval( searchField );
                    if ( searchFieldValue && searchFieldValue.toLowerCase().match( searchText.toLowerCase() ) ) {
                        // Walk parent chain
                        var ancestors = [];
                        var parent = d;
                        while (parent !== null && typeof (parent) !== "undefined") {
                            ancestors.push( parent );
                            //console.log(parent);
                            parent.class = "found";
                            parent = parent.parent;
                        }
                        console.log(ancestors);
                    }
                }

Here's the fiddle .