How to style SVG with external CSS?

It is possible to style an SVG by dynamically creating a style element in JavaScript and appending it to the SVG element. Hacky, but it works.

<object id="dynamic-svg" type="image/svg+xml" data="your-svg.svg">
    Your browser does not support SVG
</object>
<script>
    var svgHolder = document.querySelector('object#dynamic-svg');
    svgHolder.onload = function () {
        var svgDocument = svgHolder.contentDocument;
        var style = svgDocument.createElementNS("http://www.w3.org/2000/svg", "style");

        // Now (ab)use the @import directive to load make the browser load our css
        style.textContent = '@import url("/css/your-dynamic-css.css");';

        var svgElem = svgDocument.querySelector('svg');
        svgElem.insertBefore(style, svgElem.firstChild);
    };
</script>

You could generate the JavaScript dynamically in PHP if you want to - the fact that this is possible in JavaScript opens a myriad of possibilities.


You can include in your SVG files link to external css file using:

<link xmlns="http://www.w3.org/1999/xhtml" rel="stylesheet" href="mystyles.css" type="text/css"/>

You need to put this after opening tag:

<svg>
  <link xmlns="http://www.w3.org/1999/xhtml" rel="stylesheet" href="mystyles.css" type="text/css"/>
  <g>
    <path d=.../>
  </g>
</svg>

It's not perfect solution, because you have to modify svg files, but you modify them once and than all styling changes can be done in one css file for all svg files.


You can do what you want, with one (important) caveat: the paths within your symbol can't be styled independently via external CSS -- you can only set the properties for the entire symbol with this method. So, if you have two paths in your symbol and want them to have different fill colors, this won't work, but if you want all your paths to be the same, this should work.

In your html file, you want something like this:

<style>
  .fill-red { fill: red; }
  .fill-blue { fill: blue; }
</style>

<a href="//www.example.com/">
  <svg class="fill-red">
    <use xlink:href="images/icons.svg#example"></use>
  </svg>
</a>

And in the external SVG file you want something like this:

<svg xmlns="http://www.w3.org/2000/svg">
   <symbol id="example" viewBox="0 0 256 256">
    <path d="M120...." />
  </symbol>
</svg>

Swap the class on the svg tag (in your html) from fill-red to fill-blue and ta-da... you have blue instead of red.

You can partially get around the limitation of being able to target the paths separately with external CSS by mixing and matching the external CSS with some in-line CSS on specific paths, since the in-line CSS will take precedence. This approach would work if you're doing something like a white icon against a colored background, where you want to change the color of the background via the external CSS but the icon itself is always white (or vice-versa). So, with the same HTML as before and something like this svg code, you'll get you a red background and a white foreground path:

<svg xmlns="http://www.w3.org/2000/svg">
  <symbol id="example" viewBox="0 0 256 256">
    <path class="background" d="M120..." />
    <path class="icon" style="fill: white;" d="M20..." />
  </symbol>
</svg>

Your main.css file would only have an effect on the content of the SVG if the SVG file is included inline in the HTML:

https://developer.mozilla.org/en/docs/SVG_In_HTML_Introduction

<html>
  <body>
  <svg version="1.1" id="Layer_1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="0 0 56.69 56.69">
    <g>
      <path d="M28.44......."/>
    </g>
  </svg>
</html>

If you want to keep your SVG in files, the CSS needs to be defined inside of the SVG file.

You can do it with a style tag:

http://www.w3.org/TR/SVG/styling.html#StyleElementExample

<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" 
  "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg xmlns="http://www.w3.org/2000/svg" version="1.1"
     width="50px" height="50px" viewBox="0 0 50 50">
  <defs>
    <style type="text/css"><![CDATA[
      .socIcon g {
        fill:red;
      }
    ]]></style>
  </defs>
  <g>
    <path d="M28.44......./>
  </g>
</svg>

You could use a tool on the server side to update the style tag depending on the active style. In ruby you could achieve this with Nokogiri. SVG is just XML. So there are probably many XML libraries available that can probably achieve this.

If you're not able to do that, you will have to just have to use them as though they were PNGs; creating a set for each style, and saving their styles inline.

Tags:

Html

Css

Svg

External

Stylesheet

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