Let's say I have the following html context, which I don't have access to its creation :

<div id="outer">
  <div id="chart-div">
    <svg id="chart"></svg>
  </div>
  <div id="legend-div">
    <svg id="legend"></svg>
  </div>
</div>

What I'm trying to do is export this SVG to an image using canvg library, the problem here is that they are separated and so I get two canvas, and canvg library accepts a SVG definition string as input.

How can I modify the html elements above so that they are only one SVG? Using Javascript as this is a browser extension.

I have tried just switching the DIVs tags to SVG but it just broke everything and the SVG became blank

Let's say I have the following html context, which I don't have access to its creation :

<div id="outer">
  <div id="chart-div">
    <svg id="chart"></svg>
  </div>
  <div id="legend-div">
    <svg id="legend"></svg>
  </div>
</div>

What I'm trying to do is export this SVG to an image using canvg library, the problem here is that they are separated and so I get two canvas, and canvg library accepts a SVG definition string as input.

How can I modify the html elements above so that they are only one SVG? Using Javascript as this is a browser extension.

I have tried just switching the DIVs tags to SVG but it just broke everything and the SVG became blank

• javascript
• html
• svg
• html5-canvas
• canvg

• please attach example svg contents – Stranger in the Q Commented Mar 21, 2019 at 22:46
• The easier way is mixing two canvas to one image – Duannx Commented Mar 22, 2019 at 3:48

2 Answers 2

This is my solution to your problem: I make the outer div display:none, I'm creating another svg element (you may do it dynamicaly) end inside the #new svg I'm using the #chart and the #legend. I hope it helps.

svg{border:1px solid;}
#outer {display:none}
#outer div{position:absolute; width:500px;}

<div id="outer">
  <div id="chart-div">
    <svg id="chart" viewBox="0 0 300 150">
      <circle stroke="gold" fill="none" cx="100" cy="75" stroke-width="40" stroke-dasharray="124.85" stroke-dashoffset="20" r="20"  />
    </svg>
  </div>
  <div id="legend-div">
    <svg id="legend"  viewBox="0 0 300 150">
      <rect fill="skyBlue" x="200" y="100" width="80" height ="30" />
    </svg>
  </div>
</div>


<svg id="new" viewBox="0 0 300 150" width="500"> 
  <use xlink:href="#chart" />
  <use xlink:href="#legend" />
</svg>

This is a Javascript solution for merging two svg accessibles in the document through DOM manipulation.

var svgNS = "http://www.w3/2000/svg";  
var outer = document.getElementById('outer');

// get chart content
var chart = document.getElementById('chart-div');
var chartSvg = chart.getElementsByTagName('svg')[0];
var chartContent = Array.from(chartSvg.childNodes);

// get legend content
var legend = document.getElementById('legend-div');
var legendSvg = legend.getElementsByTagName('svg')[0];
var legendContent = Array.from(legendSvg.childNodes);

// create a merged-div where we are going to merge the svgs
var merged = document.createElement('div');
merged.setAttribute('id', 'merged-div');
outer.appendChild(merged);

// createElementNS for svg
var mergedSvg = document.createElementNS(svgNS, 'svg');
mergedSvg.setAttribute('id', 'merged');
// keep the viewBox of the chart
mergedSvg.setAttribute('viewBox', chartSvg.getAttribute('viewBox'));
merged.appendChild(mergedSvg);

// adding the content of both svgs
for (let i = 0; i < chartContent.length; i++) {
  mergedSvg.appendChild(chartContent[i]);
}
for (let i = 0; i < legendContent.length; i++) {
  mergedSvg.appendChild(legendContent[i]);
}

// the unmerged svgs can be removed
chart.remove();
legend.remove();

<div id="outer">
  <div id="chart-div">
    <svg id="chart" viewBox="0 0 300 150">
      <circle stroke="gold" fill="none" cx="100" cy="75" stroke-width="40" stroke-dasharray="124.85" stroke-dashoffset="20" r="20"  />
    </svg>
  </div>
  <div id="legend-div">
    <svg id="legend"  viewBox="0 0 300 150">
      <rect fill="skyBlue" x="200" y="100" width="80" height ="30" />
    </svg>
  </div>
</div>

Resulting markup:

    <div id="outer">
        <div id="merged-div">
            <svg id="merged" viewBox="0 0 300 150">
                <circle stroke="gold" fill="none" cx="100" cy="75" stroke-width="40" stroke-dasharray="124.85" stroke-dashoffset="20" r="20"></circle>
                <rect fill="skyBlue" x="200" y="100" width="80" height="30"></rect>
            </svg>
        </div>
    </div>