title: Retrive all of the same classes from an existing "g" tag
body: <p>I got a svg that as a g tag with a lot of differents tags in it (text and tspan). I just wanna try to retrieve all classname who are named "aftertext". I tried this but i don't retrieve anything..</p>
  
  <p><strong>svg</strong> is the g tag in the svg. :</p>
  
  <pre><code>function add_total_svg(svg) {
      var all_aftertext = svg.selectAll(".aftertext");
  }
  </code></pre>
  
  <p>Here is my code:</p>
  
  <p><div class="snippet" data-lang="js" data-hide="true" data-console="true" data-babel="false">
  <div class="snippet-code snippet-currently-hidden">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>var margin = {top: 30, right: 20, bottom: 30, left: 20},
      width = 400,
      barHeight = 20,
      barWidth = (width - margin.left - margin.right) * 0.8;
  
  var i = 0,
      duration = 0,
      root;
  
  var path = [];
  path[0] = {"attributes": "DPGF", "children": [{"attributes": "LOT:  nom 13.CVC", "children": [{"attributes": "Tous_DPGF:  Profondeur 1", "children": [{"attributes": "Poste:  Rang Rang 1 | 100509", "children": [{"attributes":"Debut_poste_Excel | 0.0"}, {"attributes":"Fin_poste_Excel | 19.0"}, {"attributes":"Mot_cle debut"}, {"attributes":"Rang Rang 1"}]}, {"attributes": "Poste:  Rang Rang 1 |     40", "children": [{"attributes":"Debut_poste_Excel | 20.0"}, {"attributes":"Fin_poste_Excel | 20.0"}, {"attributes":"Mot_cle chauffage"}, {"attributes":"Rang Rang 1"}]}, {"attributes": "Poste:  Rang Rang 1 |     44", "children": [{"attributes":"Debut_poste_Excel | 21.0"},
  {"attributes":"Fin_poste_Excel | 23.0"}, {"attributes":"Mot_cle Préambule"}, {"attributes":"Rang Rang 1"}]}, {"attributes": "Poste:  Rang Rang 1 |     49", "children": [{"attributes":"Debut_poste_Excel | 24.0"}, {"attributes":"Fin_poste_Excel |25.0"}, {"attributes":"Mot_cle Préambule"}, {"attributes":"Rang Rang 1"}]}, {"attributes": "Poste:  Rang Rang 1 |     53", "children": [{"attributes":"Debut_poste_Excel |26.0"}, {"attributes":"Fin_poste_Excel |27.0"}, {"attributes":"Mot_cle production thermique"}, {"attributes":"Rang Rang 1"}]}, {"attributes": "Poste:  Rang Rang 1 |     93", "children": [{"attributes":"Debut_poste_Excel | 28.0"}, {"attributes":"Fin_poste_Excel | 65.0"}, {"attributes":"Mot_cle chauffage"}, {"attributes":"Rang Rang 1"}, {"attributes": "Tous_DPGF:  Profondeur 2", "children": [{"attributes": "Poste:  Rang Rang 2", "children": [{"attributes":"Debut_poste_Excel | 31.0"}, {"attributes":"Fin_poste_Excel | 65.0"}, {"attributes":"Mot_cle Échangeur"}, {"attributes":"Rang Rang 2"}, {"attributes": "Tous_DPGF:  Profondeur 3", "children": [{"attributes": "Poste:  Rang Rang 4", "children": [{"attributes":"Debut_poste_Excel | 35.0"}, {"attributes":"Fin_poste_Excel| 35.0"},
  {"attributes":"Mot_cle Manchon"}, {"attributes":"Rang Rang 4"}]}, {"attributes": "Poste:  Rang Rang 4", "children": [{"attributes":"Debut_poste_Excel |36.0"}, {"attributes":"Fin_poste_Excel |36.0"}, {"attributes":"Mot_cle Vanne"}, {"attributes":"Rang Rang 4"}]}, {"attributes": "Poste:  Rang Rang 4", "children": [{"attributes":"Debut_poste_Excel| 37.0"}, {"attributes":"Fin_poste_Excel |37.0"}, {"attributes":"Mot_cle Thermomètre"}, {"attributes":"Rang Rang 4"}]}, {"attributes": "Poste:  Rang Rang 4", "children": [{"attributes":"Debut_poste_Excel    | 38.0"}, {"attributes":"Fin_poste_Excel| 38.0"}, {"attributes":"Mot_cle Sonde"}, {"attributes":"Rang Rang 4"}]}, {"attributes": "Poste:  Rang Rang 4", "children": [{"attributes":"Debut_poste_Excel  |39.0"}, {"attributes":"Fin_poste_Excel   |39.0"}, {"attributes":"Mot_cle Soupape"}, {"attributes":"Rang Rang 4"}]}, {"attributes": "Poste:  Rang Rang 4", "children": [{"attributes":"Debut_poste_Excel | 40.0"}, {"attributes":"Fin_poste_Excel |41.0"}, {"attributes":"Mot_cle Pressostat"}, {"attributes":"Rang Rang 4"}]}, {"attributes": "Poste:  Rang Rang 4", "children": [{"attributes":"Debut_poste_Excel             | 42.0"}]}]}]}]}]}]}]}]};
  
  var value = [];
  create_a_tree_obj(path);
  
     
  
   function add_total_svg(svg, globaldiv, cell) {
          var all_number = svg.selectAll('.node tspan.aftertext')
      .each(function (d) {
          console.log(d);
      });
      cell.attr("class", "total").attr("id", "total");
      cell.select("#title").text("Total");
      }
  
  function create_a_tree_obj(path) {
      var i = 0;
      var div;
      var cell;
      var svg_array = [];
      
      if (i === 0) {
          div = d3.select("body").append("div")
              .attr("id", "div");
      }
      for (i ; path[i]; i++) {
          cell = div.append("div").attr("class", "cell").attr("id", "cell");
          svg_array[i] = cell.append("svg")
          .attr("id", "" + i)
          .attr("width", 600) // + margin.left + margin.right)
          .append("g")
          .attr("transform", "translate(" + margin.left + "," + margin.top + ")");
          add_the_tree_graph(svg_array, path, i);
      }
      add_total_svg(svg_array[i - 1], div);
  }
  
  function add_the_tree_graph(svg_array, path, i) {
      var root = [];
      
  //    d3.json(path[i], function(error, json) {
  //        if (error) throw error;
          for (; path[i]; i++) { 
              root[i] = d3.hierarchy(path[i]);
              root[i].x0 = 0;
              root[i].y0 = 0;
              update(root[i], svg_array[i], "" + i, root);
          }
  //    });
  }    
  
  function update(source, svg_var, svg_id, all_sources) {
  
    // Compute the flattened node list.
      var nodes = source.descendants();
      var height = Math.max(500, nodes.length * barHeight + margin.top + margin.bottom);
  
      document.getElementById(svg_id).setAttribute("height", height);
  
    d3.select(self.frameElement).transition()
        .duration(duration)
        .style("height", height + "px");
  
    // Compute the "layout". TODO https://github.com/d3/d3-hierarchy/issues/67
    var index = -1;
    source.eachBefore(function(n) {
      n.x = ++index * barHeight;
      n.y = n.depth * 20;
    });
  
    // Update the nodes…
    var node = svg_var.selectAll(".node")
      .data(nodes, function(d) { return d.id || (d.id = ++i); });
  
    var nodeEnter = node.enter().append("g")
        .attr("class", "node")
        .attr("transform", function(d) { return "translate(" + source.y0 + "," + source.x0 + ")"; })
        .style("opacity", 0);
  
    // Enter any new nodes at the parent's previous position.
    nodeEnter.append("rect")
        .attr("y", -barHeight / 2)
        .attr("height", barHeight)
        .attr("width", barWidth)
        .style("fill", color)
        .on("click", function(d, e) {
        if (d.children) {
              d._children = d.children;
              d.children = null;
        } else {
          d.children = d._children;
          d._children = null;
        }
        update(source, svg_var, svg_id, all_sources); //recursion pour re-afficher la page dynamiquement.
      });
      nodeEnter.append("text")
      .attr("dy", 3.5)
      .attr("dx", 5.5)
      .each(function (d) {
      if(d.data.attributes.indexOf('|') &gt; -1) {
          var beforeText = d.data.attributes.substr(0,   d.data.attributes.indexOf('|')).trim(),
          afterText = d.data.attributes.substr(d.data.attributes.indexOf('|')+1, d.data.attributes.length).trim();
  
          d3.select(this).append('tspan').classed('beforetext', true).text(beforeText);
          var afterTextSpan = d3.select(this).append('tspan').classed('aftertext', true).text(afterText);
  
      // position aftertext
          var temp_text = svg_var.append('text').classed('temp_text', true).text(afterText);
          afterTextSpan.attr('x', (288 - afterText.length * 6) - 5)
          temp_text.remove();
      } else {
          d3.select(this).text(d.data.attributes); 
      }
    });
  
    // Transition nodes to their new position.
      nodeEnter.transition()
        .duration(duration)
        .attr("transform", function(d) { return "translate(" + d.y + "," + d.x + ")"; })
        .style("opacity", 1);
      node.transition()
        .duration(duration)
        .attr("transform", function(d) { return "translate(" + d.y + "," + d.x + ")"; })
        .style("opacity", 1)
      .select("rect")
        .style("fill", color);
  
    // Transition exiting nodes to the parent's new position.
    node.exit().transition()
        .duration(duration)
        .attr("transform", function(d) { return "translate(" + source.y + "," + source.x + ")"; })
        .style("opacity", 0)
        .remove();
  }
  
  //setTimeout(() =&gt; simulateClick(240, 141), 2000); //Click test worked
  function color(d) {
    return d._children ? "#3182bd" : d.children ? "#c6dbef" : "#fd8d3c";
  }</code></pre>
  <pre class="snippet-code-css lang-css prettyprint-override"><code>.node rect {
    cursor: pointer;
    fill: #fff;
    fill-opacity: 0.5;
    stroke: #3182bd;
    stroke-width: 1.5px;
  }
  
  #div { display: table-row; }
  #div .cell { display: table-cell; vertical-align: top;}
      
  .node text {
    font: 10px sans-serif;
    pointer-events: none;
  }
  
  .link {
    fill: none;
    stroke: #9ecae1;
    stroke-width: 1.5px;
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;script src="https://d3js.org/d3.v4.min.js"&gt;&lt;/script&gt;</code></pre>
  </div>
  </div>
  </p>
  
  <p>i only need to retrieve in a array all classes who are named "aftertext" (the blue rect with a number) ..</p>