Setting the Viewbox so that the inline SVG will “Snap” to the size of the containing element?

I created this simple inline SVG by saving as "Optimized SVG" in inkscape. Prior to saving I set the size to 200X200px.

<div style="width: 200px; background-color: red;">
          <?xml version="1.0" encoding="UTF-8"?>
        <svg viewBox="0 0 200 200" version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:cc="http://creativecommons.org/ns#" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
         <g>
          <path class="fs-logo-fill" d="m71.679 40.782v52.917h52.917v-52.917zm26.458 7.2166a19.242 19.242 0 0 1 19.242 19.242 19.242 19.242 0 0 1-19.242 19.242 19.242 19.242 0 0 1-19.242-19.242 19.242 19.242 0 0 1 19.242-19.242z"/>
         </g>
        </svg>

I then put it inside a the div element seen that has a width of 200px.

This is the codepen:

https://codepen.io/oleersoy/pen/dLxvEJ

As can be seen the red div is a lot larger than the inline svg rendering. How do we set the viewbox parameters so that the inline SVG will always fit the size of the containing element?

Solution

In order to get the viewBox right you need to get the size of the bounding box of the path, and use the values you get to define the viewBox.

console.log(thePath.getBBox())

<div style="width: 200px; background-color: red;">
          
        <svg viewBox="71.68 40.782 52.92 52.92" style="display:block;">
         <g>
          <path id="thePath" class="fs-logo-fill" d="m71.679 40.782v52.917h52.917v-52.917zm26.458 7.2166a19.242 19.242 0 0 1 19.242 19.242 19.242 19.242 0 0 1-19.242 19.242 19.242 19.242 0 0 1-19.242-19.242 19.242 19.242 0 0 1 19.242-19.242z"/>
         </g>
        </svg>
</div>

In this case the bounding box of the path is:

let BB = {
  "x": 71.67900085449219,
  "y": 40.78200149536133,
  "width": 52.91699981689453,
  "height": 52.9170036315918
}

The viewBox will have this aspect:

viewBox=`${BB.x} ${BB.y} ${BB.width} ${BB.height}`