optimus_prime optimus_prime - 1 year ago 187
HTML Question

Drop down button to filter a d3.js graph

I have a graph that works fine and even filters the data on button click. Now I am trying to use a drop down button instead of a regular button. When a user chooses Amount as either 1000 or 2000 from the drop down , nodes and links should get filtered based on the property

d.total_amt> 1000 or d.total_amt > 2000


.links line {
stroke: #999;
stroke-opacity: 0.6;

.nodes circle {
stroke: #fff;
stroke-width: 1.5px;

.nodes circle {
stroke: #fff;
stroke-width: 1.5px;

div.tooltip {
position: absolute;
background-color: white;
max-width: 200px;
height: auto;
padding: 1px;
border-style: solid;
border-radius: 4px;
border-width: 1px;
box-shadow: 3px 3px 10px rgba(0, 0, 0, .5);
pointer-events: none;

<svg id="Network_graph" width="400" height="350"></svg>

<label for="input ID">Amount</label>
<select id="select_ID" name="select_ID">
<option value="1000">1000</option>
<option value="2000">2000</option>
<button id="full_data">
full data


var IDData = JSON.stringify([
["node/105173", "node/38180995", "Agent", "Customer", "1379644.0", 1, 264, "1374903"],
["node/1061", "node/21373542", "Agent", "Customer", "530848.0", 1, 3000, "529502"],
["node/10750", "node/59648369", "Agent", "Customer", "1454228.0", 1, 120, "1454118"],
["node/10750", "node/78569210", "Agent", "Customer", "1425251.0", 1, 234, "1421416"],
["node/10750", "node/96726118", "Agent", "Customer", "1376239.0", 1, 434, "1376152"],
["node/10946829", "node/11190", "Customer", "Agent", "1409620.0", 20, 3380, "1406665"],
["node/10946829", "node/57774036", "Customer", "Customer", "1460029.0", 3, 960, "1459731"],
["node/109947", "node/97911872", "Agent", "Customer", "1323025.0", 1, 600, "1315582"],..])

Below is the piece of code that will make this data in a format suitable to render the graph:

var galData = JSON.parse(IDData);
var startnodes = [];
var endnodes = [];
var startnodetype = [];
var endnodetype = [];
var PayTime = [];
var TXN_COUNT = [];
var Total_Amt = [];
var SendTime = [];
galData.map(function(e, i) {
var final_data = createNodes(startnodes, endnodes, startnodetype, endnodetype, PayTime, TXN_COUNT, Total_Amt, SendTime);
makeGraph("#Network_graph", final_data);

I have made a force directed graph using this data. Jsfiddle is the link to the working graph.

Now I am trying to add drop down for data filtering. This is the section of code that holds on to the selection from the drop down

d3.select(this) //right way to hold on to the selection or need some jquery?
.filter(function(d, i) {
return this.selected;

This piece of code uses the filter function to filter the nodes and links.

function isUnique(id, nodes) {
for (var i = 0; i < nodes.length; i++) {
if (nodes[i].id == id) {
return false;
return true;

var filtered_data = [];
var nodes = [];
var links = [];
d3.selectAll("line").filter(function(d, i) {
if (d.total_amt > this.value) {
if (isUnique(d.source.id, nodes)) {

if (isUnique(d.target.id, nodes)) {
filtered_data.links = links;
filtered_data.nodes = nodes;
filtered_data.nodetype = final_data.nodetype;

makeGraph("#Network_graph", filtered_data);

Does the above approach make sense? So , far this has not worked. I don't know what is the missing piece. I am open to other ideas too that may work better for a drop down. Still finding my way around d3.js /javascript. Looking forward for some help.

Answer Source


Here's the code you need:

var elem = document.getElementById('select_ID');
elem.addEventListener("change", onSelectChange);

function onSelectChange(){
  var value = this.value;
  var fdata = filteredData(value);
  makeGraph("#Network_graph", fdata);

In order to do something when your select option changes. Select the element and attach an event listener (change in this case) to it.

var elem = document.getElementById('select_ID');
elem.addEventListener("change", onSelectChange);

And inside this change event get the value with this.value as you've already said and make the filtering.

Here's the fiddle: https://jsfiddle.net/tgv6s5cd/14/

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