reactjs d3 tree component

index.html

<div id="huffmandemo">
  <textarea id="RawText">🍒🍊🍍🍑🍎🍌🍑🥝🍎🍎🍇🍊🍇🍌🍎🍎🍎🍊🍎🍉🍎🍉🍎🍑🍌🍇🍍🍊🍎🍊🍎🍇🍎🍌🍓🍓🍎🍊🍓🍉🍍🍓🍎🍎🍌🍌🍎🍇🍌🍎🍉🍉🍌🍊🍇🍍🍎🍓🍌🥝🍊🍇🍌🍊🍌🍎🍎🍊🍍🍎🍇🍊🍌🍒🍇🍌🍎🍎🍎🍎🍊🍌🍌🍌🍇🍎🍑🍎🍑🍊🍌🍊🍎🍌🍌🍒🍎🍌🍎🍊</textarea>
  <div id="TreeChart"></div>
  <button id="reset">reset tree</button>
  <button id="step">Step</button>
  <button id="stepAll">Build Tree</button>
  <pre>
  <code id="codebook" class="language-python" data-lang="python">
  </code>
  </pre>
</div>

reactjs-d3-tree-component.markdown

reactjs d3 tree component

A Pen by Shawn Tan on CodePen.

License.

script.babel

function initTree()  {
  let d3Tree = {};
d3Tree.create = function(el, props, state) {
  let svg = d3.select(el).append('svg')
    .attr('width', props.width)
    .attr('height', props.height);
  this.width = props.width;
  this.height = props.height;
  var compWidth = el.getBoundingClientRect().width;
  this.tree = d3.layout.tree().size([compWidth, 300]);
  this.svg = d3.select(el).select('svg');
  this.nodeCounts = 0;
  this.update(el, state);
};

d3Tree.update = function(el, state, cb)  {
  console.log("update", el, state, cb);
  return this._drawTree(el, state.data, cb);
};

d3Tree._drawTree = function(el, data, cb) {
  let tree = this.tree;
  let svg = this.svg;
  let nodes = tree.nodes(data);
  let nodeCounts = this.nodeCounts;
  let g = svg.selectAll('g.node')
             .data(nodes, (d) => d.id || (d.id = ++nodeCounts));
  this.nodeCounts = nodeCounts;
  
  let node = g.data(nodes);
  let p = svg.selectAll('path.link');
  let link = p.data(tree.links(nodes.slice(1)), 
                    function(d) { return d.target.id; });
  let linkLabel = svg.selectAll('text.link-label')
                     .data(tree.links(nodes.slice(1)), (d) => d.target.id);
  // let nodeLabels = svg.selectAll('text.tree-node-label').data(node, )
  g = node.enter().append('svg:g')
    .attr('class', 'node')
    .attr('transform', (d) => `translate(${d.x},${d.y-10})`);
  
  g.append("svg:circle")
    .attr('fill', '#AAAAAA')
    .attr('stroke', '#000000')
    .attr('stroke-width', 2)
    .attr('class', 'treenode')
    .attr("r", d => d.root?0:(15 * Math.sqrt(d.p)));
  
  g.append('text')
   .attr('dy', 30)
   .attr('text-anchor', 'middle')
   .attr('class', 'treesymbol')
   .text((d) => d.symbol)
  
  g.append('text')
    .attr('text-anchor', 'middle')
    .attr('class', 'treep')
    .attr('dy', -16)
    .text((d) => d.p?Number(d.p).toFixed(2):"" );
 
  link.enter().insert("svg:path", "g")
    .attr('class', 'link')
    .attr('style', d => d.root?'display:none':'display:visible')
    .attr('d', function(d) {
      var o = {x: d.source.x, y: d.source.y};
      return d3.svg.diagonal().projection(function(d) {
        return [o.x, o.y - 10];
      })(d);
    });
  
  linkLabel.enter().append('text')
           .attr('class', 'link-label')
           .attr('text-anchor', 'middle')
           .attr('x', d => (d.source.x + d.target.x) / 2)
           .attr('y', d => (d.source.y + d.target.y) / 2)
           .text(d => d.edgeLabel || (d.edgeLabel = d.source.children && d.source.children[0] === d.target ? '0' : '1'));
  
  
  var duration = 250;
  var transitionCounts = node.length
  let t = node.transition()
    .duration(duration)
    .attr('transform', (d) => `translate(${d.x},${d.y})`)
    .each('end', function(d) {
      transitionCounts--;
      if (transitionCounts == 0 && cb) {
        cb();
      }
    } )
  
  link.transition()
    .duration(duration)
    .attr('d', (d) => `M${d.source.x},${d.source.y}L${d.target.x},${d.target.y}`);
  
  linkLabel.transition()
    .duration(duration)
    .attr('text-anchor', 'middle')
    .attr('x', d => (d.source.x + d.target.x) / 2)
    .attr('y', d => (d.source.y + d.target.y) / 2)
    .attr('dx', d => d.source.children && d.source.children[0] === d.target ? -10:10)
    .text(d => d.source.children && d.source.children[0] === d.target ? '0' : '1');
  
  link.exit().remove();
  return t;
};
 return d3Tree;
}

var state = {
  data: {
        "root": true,
        "children": []
      }
}
state.countSymbols = function() {
  textbox = document.getElementById("RawText");
  var freq = {};
  var string = textbox.value;
  var totalCount = 0;
  for (const character of string) {
    freq[character] = (freq[character]?freq[character]:0) + 1;
    totalCount += 1;
  }
  dataNodes = [];
  for (var k in freq) {
    dataNodes.push({"symbol": k, "p": freq[k] / totalCount});
  }
  
  console.log(dataNodes);
  this.data.children = dataNodes;
}

state.computeCodeBook = function() {
  var currNode = this.data.children[0];
  console.log(currNode);
  var codebook = {};
  function dfs(node, code) {
    
    if (node.symbol) {
      codebook[node.symbol] = code;
      console.log(code);
    }
    else {
      
      dfs(node.children[0], code + "0");
      dfs(node.children[1], code + "1");
    }
  }
  dfs(currNode, "");
  document.getElementById("codebook").innerHTML = JSON.stringify(codebook, null, 2);
}
state.addNode = function(cb) {
    //this.state.data.children = this.state.data.children||[];
    //this.state.data.children.push({});
    var children = this.data.children;
    if (children.length == 1) return;
    children.sort((a, b) => b.p - a.p);
    var self = this;
    function noop() {}
    function merge() {
      var child2 = children.pop();
      var child1 = children.pop();
      children.push({
        "children": [child1, child2],
        "p": child1.p + child2.p
      });
      
      state.d3Tree.update(this.el, self, cb);
      if (children.length == 1) {
        state.computeCodeBook();
      }
    };
    console.log("before running, ", merge)
    this.d3Tree.update(this.el, self, merge);
}

state.addAllNodes = function() {
  var children = this.data.children;
  function nextStep() {
    state.addNode(function () {
      if (children.length == 1) return;
      else {
        nextStep();
      }
    });
  }
  nextStep();
}

state.init = function() {
  state.data =  {
          "root": true,
          "children": []
        };
  this.d3Tree = initTree();
  const el = document.getElementById("TreeChart");
  this.el = el
  this.el.innerHTML = '';
  this.countSymbols();
  this.d3Tree.create(this.el, {width: '100%', height: '400px'}, state);
}


state.init();

var resetBtn = document.getElementById("reset");
resetBtn.onclick = function() {
  console.log("hello reset");
  state.init();
};

var stepBtn = document.getElementById("step");
stepBtn.onclick = function() {  state.addNode(); };


var stepBtn = document.getElementById("stepAll");
stepBtn.onclick = function() {  state.addAllNodes(); };

scripts

<script src="https://npmcdn.com/react@15.3.0/dist/react.min.js"></script>
<script src="https://npmcdn.com/react-dom@15.3.0/dist/react-dom.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.17/d3.min.js"></script>

style.css

#huffmandemo {
  width: 100%;
}
.link {
  fill: none;
  stroke: black;
  stroke-width: 1.5px;
}
g {
    overflow: visible;
}
g.node { 
  background-color: gray;
  height: 40px;
}

g.node circle {
  background-color: #AAAAAA;
  color: #AAAAAA;
}
text {
    overflow: visible;
  line-height: 5;
  font-size: 2em;
  font-family: monospace;
}
text.treep {
  display: none;
}
.node:hover text.treep {
  display: block;

}


text.treesymbol {
  overflow: visible;
  line-height: 5;
  font-size: 2em;
  font-family: monospace;
}

#RawText {
  min-height: 50px;
  width: 100%;
  padding: 10px;
  font-size: 18px;
  line-height: 1.5;
  border: solid 1px;
  resize: none; /* disable resizing */
  border-radius: 5px;
}
#TreeChart {
  align-content: center;
  width: 100%;
  
}
#TreeChart svg{
  width: 100%;
  display: block;
}