Convert svg into base64

Question

SVG which was created programmatically does not convert into base64 correctly.

In my application I\'ve got a service which get a response with g-element and then pu

Answer 1

HTML elements and SVG elements have different namespaces. By putting the <g> element in your HTML you have created an <html:g> element. When it is moved inside the <svg>, it is still an <html:g> and won't be recognised by the SVG renderer.

You either have to put it inside soem <svg> tags as @guest271314 described. Or, after you append to the SVG, go through all the elements in the <g> and change all their namespaces to the SVG one.

Answer 2

Difference between @guest271314 and my answer:

@guest271314 his answer:

Wrap the g element inside a svg element to make sure that the browser renders the g element onload.

My answer:

Forces the svg element inside #test to render the g element since the g element wasn't rendered onload.

Best answer in this case: @guest271314

Reason: A g element should be inside a svg element in valid html.

When should my answer be used?
In the case that the g element is not an element in the html document.

You didn't close test() with a }. Code below returns a base64 encoded svg: https://jsfiddle.net/seahorsepip/6sra5c5L/1/

Edit:

svg render issue is something I ran into myself before, here's the fix with a line of jquery: https://jsfiddle.net/seahorsepip/6sra5c5L/3/

//Force refresh svg
$("#test").html($("#test").html());

Here's the original SO thread about the issue: jquery's append not working with svg element?

I don't know the javascript equivalent for the jQuery code I added, I tried to write it but it didn't work :/

Edit 2:

Here's the pure js equivalent:

https://jsfiddle.net/seahorsepip/6sra5c5L/4/

//Force refresh svg
var svg = document.body.querySelector('#test').innerHTML;
document.body.querySelector('#test').innerHTML = "";
document.body.querySelector('#test').innerHTML = svg;

Answer 3

Try adding <svg></svg> around <g> element , closing } at test function ; defining test as a named function

    var xmlns = 'http://www.w3.org/2000/svg',
      IMAGE_TEMPLATE = document.createElementNS(xmlns, 'svg');
    IMAGE_TEMPLATE.appendChild(document.body.querySelector('#ico-appliance-thermostat-128'));
    IMAGE_TEMPLATE.setAttribute('id', 'svg');
    IMAGE_TEMPLATE.setAttributeNS(null, 'width', 128);
    IMAGE_TEMPLATE.setAttributeNS(null, 'height', 128);
    IMAGE_TEMPLATE.setAttributeNS(null, 'viewBox', '0 0 128 128');

    document.body.querySelector('#test').appendChild(IMAGE_TEMPLATE);

    function test() {
      var s = new XMLSerializer().serializeToString(document.getElementById("svg"))
      console.log(document.getElementById("svg"))
      console.log(s)
      var encodedData = window.btoa(s);
      console.log('data:image/svg+xml;base64,' + encodedData);
    }

<svg>
  <g id="ico-appliance-thermostat-128" transform="scale(2)">
    <path d="M106.949,128.009 L105.294,124.692 C115.967,119.333 123.298,108.278 123.298,95.500 C123.298,82.722 115.967,71.666 105.294,66.308 L106.949,62.990 C118.835,68.958 126.999,81.270 126.999,95.500 C126.999,109.730 118.835,122.042 106.949,128.009 ZM117.376,95.500 C117.376,105.954 111.378,115.000 102.645,119.384 L100.990,116.067 C108.510,112.292 113.676,104.502 113.676,95.500 C113.676,86.497 108.510,78.708 100.990,74.933 L102.645,71.615 C111.378,76.000 117.376,85.045 117.376,95.500 ZM106.999,95.213 C106.999,98.063 104.756,100.373 101.988,100.373 C100.251,100.373 98.720,99.462 97.822,98.080 L91.490,98.080 L85.840,116.427 L85.662,116.427 L85.840,117.000 L80.829,117.000 L70.082,82.422 L65.795,97.506 L65.795,98.080 L54.999,98.080 L54.999,92.920 L62.087,92.920 L67.465,74.000 L72.477,74.000 L83.234,108.615 L88.067,92.920 L89.738,92.920 L93.079,92.920 L97.504,92.920 C98.324,91.222 100.021,90.053 101.988,90.053 C104.756,90.053 106.999,92.363 106.999,95.213 ZM24.999,128.000 C11.787,128.000 0.999,117.189 0.999,103.993 C0.999,96.779 4.177,90.380 8.986,85.988 C8.986,85.173 8.986,84.776 8.986,83.981 L8.986,15.997 C8.986,7.193 16.177,-0.000 24.979,-0.000 C33.780,-0.000 40.972,7.193 40.972,15.997 L40.972,83.981 C40.972,84.796 40.972,85.194 40.972,85.988 C45.780,90.380 48.979,96.779 48.999,103.993 C48.999,117.210 38.212,128.000 24.999,128.000 ZM33.999,90.000 L33.999,17.000 C33.999,12.373 29.662,8.009 24.988,8.009 C20.314,8.009 16.000,12.373 16.000,17.000 L16.000,90.000 C10.903,92.952 7.985,97.813 7.985,104.136 C7.985,113.411 15.641,120.990 25.011,120.990 C34.380,120.990 42.037,113.389 41.992,104.114 C41.992,97.791 39.118,92.952 33.999,90.000 ZM24.999,112.990 C19.904,112.990 15.999,109.082 15.999,103.983 C15.999,100.092 18.383,96.796 21.989,95.588 C21.989,95.290 21.989,95.290 21.989,94.992 L21.989,38.991 C21.989,37.500 23.181,35.994 24.984,35.994 C26.787,35.994 27.979,37.187 27.979,38.991 L27.979,95.008 C27.979,95.306 27.979,95.306 27.979,95.604 C31.585,96.812 33.984,100.107 33.999,103.983 C33.999,109.082 30.095,112.990 24.999,112.990 Z"
    style="fill: #5aac21;fill-rule: evenodd;"></path>
  </g>
</svg>
<div id="test"></div>
<button onclick="test()">Test</button>

jsfiddle https://jsfiddle.net/6sra5c5L/5/

Answer 4

I don't see a full explanation what actually happened anywhere here, so here it goes.

Browsers parse HTML as HTML

While this seems obvious, it is not so in the case, when you put non-HTML (SVG, XML, ...) elements into it.

Browsers are too nice and when you provide valid SGML (parent of XML, HTML, ...) and they find element that doesn't belong there(<g>) according to what you said will be there (HTML) - they don't complain and only treat the unknown elmenents as unknown HTML elements, resulting in class HTMLUnknownElement.

Browsers generally don't change element object class

So you are basically putting HTMLUnknownElement into SVGSVGElement, which will put the tag content into the svg, but since the underlying object is not a valid subelement of SVG (SVGGElement) it won't do anything.
This is the same reason why dynamically created <svg> has to be created with namespace => the namespace, when combined with <svg> element, is telling browser - hey!, this tag is from SVG specification => treat it as an SVG!

Solutions

Your current example code has a syntax error, which I will not address, since that is not the real issue.

Statically defined <g> template

If the template is already in the original document - force browser to take it as SVGSVGElement by wrapping with <svg xmlns="http://www.w3.org/2000/svg"></svg> (browsers may eat it without xmlns attribute, but it is the safer way).
Worried that it would display? Just hide it with CSS display: none; - it will not affect the rendering.

Dynamically defined <g> template

If you are creating <g> element dynamically, you should create it while specifying the namespace using createElementNS() like:

document.createElementNS('http://www.w3.org/2000/svg', 'g');

Static, but non-changable <g> template

If you are stuck in the middle and can't change the static template, you can still build upon the dynamic approach:

1. create new <g> with the right namespace

   var newGroup = document.createElementNS('http://www.w3.org/2000/svg', 'g');

2. get the "raw" old <g> - it will be HTMLUnknownElement, but it is ok, since it is built upon HTMLElement and that gives us enaugh API to transfer all we need

   var oldGroup = document.querySelector('oldGroupSelector');

3. possibly transfer old group attributes to new group - handy is element.attributes

   for (var i = 0; i < oldGroup.attributes.length; ++i) { newGroup.setAttribute( oldGroup.attributes.item(i).name, oldGroup.attributes.item(i).value ); }

4. Now browser already knows contents of newGroup <g> are actually svg - newGroup is SVGGElement - now we can just refill the contents

   newGroup.innerHTML = oldGroup.innerHTML;