SVG<use>It

About

In many web projects there are browser lists including IE10 and 11 which sadly don't support SVG fragment identifiers on external resources.

This polyfill solves this problem by simply inlining the referenced shapes from the given file without user agent sniffing.

Usage

SVG gives us the ability to use instances of shapes which is pretty amazing for icon libraries. Just add a svg tag to your markup with a use tag as child and add your resource's file path with the id hash of your desired shape like this:

<svg viewBox="0 0 64 64">
    <!-- referencing id "menu" from "/path/to/my/icons.svg" -->
    <use xlink:href="/path/to/my/icons.svg#menu"></use>
</svg>

Just import svgUseIt into your script (which gets included at the bottom of your HTML) or execute it on DOMContentLoaded:

import svgUseIt from 'svg-use-it';
 
document.addEventListener('DOMContentLoaded', () => {
    svgUseIt();
});

Options

svgUseIt takes two paramters:

rootSelector

Provide a root selector to search in <string>.

• Default: body
• Optional: true

blacklist

You can pass an array of direct children of rootSelector to be ignored for replacement.

• Default: []
• Optional: true

Good to know

Feature detection

Of course this polyfill should only do its job on browsers that don't support fragment identifiers from external resources. So I researched for a feature that could identify each IE except for MSEdge. Due to the fact, that documentMode is just supported in Internet Explorer <= 11, we can use it here to detect support for external fragments.

// false on all browsers except for IE <= 11
Boolean(document.documentMode);