Resize svg when window is resized in d3.js

Question

Look for 'responsive SVG' it is pretty simple to make a SVG responsive and you don't have to worry about sizes any more.

Here is how I did it:

d3.select("div#chartId")
   .append("div")
   // Container class to make it responsive.
   .classed("svg-container", true) 
   .append("svg")
   // Responsive SVG needs these 2 attributes and no width and height attr.
   .attr("preserveAspectRatio", "xMinYMin meet")
   .attr("viewBox", "0 0 600 400")
   // Class to make it responsive.
   .classed("svg-content-responsive", true)
   // Fill with a rectangle for visualization.
   .append("rect")
   .classed("rect", true)
   .attr("width", 600)
   .attr("height", 400);

.svg-container {
  display: inline-block;
  position: relative;
  width: 100%;
  padding-bottom: 100%; /* aspect ratio */
  vertical-align: top;
  overflow: hidden;
}
.svg-content-responsive {
  display: inline-block;
  position: absolute;
  top: 10px;
  left: 0;
}

svg .rect {
  fill: gold;
  stroke: steelblue;
  stroke-width: 5px;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/5.7.0/d3.min.js"></script>

<div id="chartId"></div>

Note: Everything in the SVG image will scale with the window width. This includes stroke width and font sizes (even those set with CSS). If this is not desired, there are more involved alternate solutions below.

More info / tutorials:

http://thenewcode.com/744/Make-SVG-Responsive

http://soqr.fr/testsvg/embed-svg-liquid-layout-responsive-web-design.php

Use window.onresize:

function updateWindow(){
    x = w.innerWidth || e.clientWidth || g.clientWidth;
    y = w.innerHeight|| e.clientHeight|| g.clientHeight;

    svg.attr("width", x).attr("height", y);
}
d3.select(window).on('resize.updatesvg', updateWindow);

http://jsfiddle.net/Zb85u/1/

UPDATE just use the new way from @cminatti

---

old answer for historic purposes

IMO it's better to use select() and on() since that way you can have multiple resize event handlers... just don't get too crazy

d3.select(window).on('resize', resize); 

function resize() {
    // update width
    width = parseInt(d3.select('#chart').style('width'), 10);
    width = width - margin.left - margin.right;

    // resize the chart
    x.range([0, width]);
    d3.select(chart.node().parentNode)
        .style('height', (y.rangeExtent()[1] + margin.top + margin.bottom) + 'px')
        .style('width', (width + margin.left + margin.right) + 'px');

    chart.selectAll('rect.background')
        .attr('width', width);

    chart.selectAll('rect.percent')
        .attr('width', function(d) { return x(d.percent); });

    // update median ticks
    var median = d3.median(chart.selectAll('.bar').data(), 
        function(d) { return d.percent; });

    chart.selectAll('line.median')
        .attr('x1', x(median))
        .attr('x2', x(median));


    // update axes
    chart.select('.x.axis.top').call(xAxis.orient('top'));
    chart.select('.x.axis.bottom').call(xAxis.orient('bottom'));

}

http://eyeseast.github.io/visible-data/2013/08/28/responsive-charts-with-d3/

It's kind of ugly if the resizing code is almost as long as the code for building the graph in first place. So instead of resizing every element of the existing chart, why not simply reloading it? Here is how it worked for me:

function data_display(data){
   e = document.getElementById('data-div');
   var w = e.clientWidth;
   // remove old svg if any -- otherwise resizing adds a second one
   d3.select('svg').remove();
   // create canvas
   var svg = d3.select('#data-div').append('svg')
                                   .attr('height', 100)
                                   .attr('width', w);
   // now add lots of beautiful elements to your graph
   // ...
}

data_display(my_data); // call on page load

window.addEventListener('resize', function(event){
    data_display(my_data); // just call it again...
}

The crucial line is d3.select('svg').remove();. Otherwise each resizing will add another SVG element below the previous one.

In force layouts simply setting the 'height' and 'width' attributes will not work to re-center/move the plot into the svg container. However, there's a very simple answer that works for Force Layouts found here. In summary:

Use same (any) eventing you like.

window.on('resize', resize);

Then assuming you have svg & force variables:

var svg = /* D3 Code */;
var force = /* D3 Code */;    

function resize(e){
    // get width/height with container selector (body also works)
    // or use other method of calculating desired values
    var width = $('#myselector').width(); 
    var height = $('#myselector').height(); 

    // set attrs and 'resume' force 
    svg.attr('width', width);
    svg.attr('height', height);
    force.size([width, height]).resume();
}

In this way, you don't re-render the graph entirely, we set the attributes and d3 re-calculates things as necessary. This at least works when you use a point of gravity. I'm not sure if that's a prerequisite for this solution. Can anyone confirm or deny ?

Cheers, g

For those using force directed graphs in D3 v4/v5, the size method doesn't exist any more. Something like the following worked for me (based on this github issue):

simulation
    .force("center", d3.forceCenter(width / 2, height / 2))
    .force("x", d3.forceX(width / 2))
    .force("y", d3.forceY(height / 2))
    .alpha(0.1).restart();