How to calculate the dimensions of an SVG element

Question

How to calculate the dimensions of an element svg consistently across browsers? In fact the only one not to respond consistently is Firefox.

It would be interesting to understand the reason for the disparities in getBoundingClientRect in different browsers also.

I tried to compare the results using getBoundingClientRect and getComputedStyle. The getComputedStyle is consistent but does not exist in IE8.

var svg = document.querySelector('svg');
var gBCR = svg.getBoundingClientRect().width;
var bBox = svg.getBBox().width;
var gCS = window.getComputedStyle(svg, null).width;
console.log('gBCR: ' + Math.round(gBCR) + ' - gCS: ' + gCS + ' - bBox: ' + Math.round(bBox));

// Resultados:
// Firefox: gBCR: 142 - gCS: 400px - bBox: 363
// Chrome:  gBCR: 400 - gCS: 400px - bBox: 363 

http://jsfiddle.net/23x8S/

HTML:

<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512" height="200px">
    <title>HTML5 Logo</title>
    <polygon fill="#E44D26" points="107.644,470.877 74.633,100.62 437.367,100.62 404.321,470.819 255.778,512" />
    <polygon fill="#F16529" points="256,480.523 376.03,447.246 404.27,130.894 256,130.894             " />
    <polygon fill="#EBEBEB" points="256,268.217 195.91,268.217 191.76,221.716 256,221.716 256,176.305 255.843,176.305 142.132,176.305 143.219,188.488 154.38,313.627 256,313.627" />
    <polygon fill="#EBEBEB" points="256,386.153 255.801,386.206 205.227,372.55 201.994,336.333 177.419,336.333 156.409,336.333 162.771,407.634 255.791,433.457 256,433.399" />
    <path d="M108.382,0h23.077v22.8h21.11V0h23.078v69.044H152.57v-23.12h-21.11v23.12h-23.077V0z" />
    <path d="M205.994,22.896h-20.316V0h63.72v22.896h-20.325v46.148h-23.078V22.896z" />
    <path d="M259.511,0h24.063l14.802,24.26L313.163,0h24.072v69.044h-22.982V34.822l-15.877,24.549h-0.397l-15.888-24.549v34.222h-22.58V0z" />
    <path d="M348.72,0h23.084v46.222h32.453v22.822H348.72V0z" />
    <polygon fill="#FFFFFF" points="255.843,268.217 255.843,313.627 311.761,313.627 306.49,372.521 255.843,386.191 255.843,433.435 348.937,407.634 349.62,399.962 360.291,280.411 361.399,268.217 349.162,268.217" />
    <polygon fill="#FFFFFF" points="255.843,176.305 255.843,204.509 255.843,221.605 255.843,221.716 365.385,221.716 365.385,221.716 365.531,221.716 366.442,211.509 368.511,188.488 369.597,176.305" />
<svg>

Cross-post in the OS: https://stackoverflow.com/q/23731026/2256325

Answer 1

The most consistent solution seems to be .getComputedStyle. And since IE8 does not support svg elements, neither the .getComputedStyle so in the case of IE8 and earlier "Unsolved problem is`.

So, as I put in the question this morning getComputedStyle gives the same value between FF and Chrome. I then created a function to take into account margin and padding:

The Solution I found for this was to use .getComputedStyle(). And Since svg Elements are not supported in old IE8- browsers, computed style is the way to Give consistent Results.

So I ended up making in my library:

function svgSize(el) {
    var gCS = window.getComputedStyle(this),
        bounds;
    var gCScomponents = {
        height: ['height', 'paddingTop', 'paddingBottom', 'borderTopWidth', 'borderBottomWidth'],
        width: ['width', 'paddingLeft', 'paddingRight', 'borderLeftWidth', 'borderRightWidth']
    };
    bounds = {
        x: 0,
        y: 0
    };
    gCScomponents.height.each(function (css) {
        bounds.y += computeSize(gCS[css]);
    });
    gCScomponents.width.each(function (css) {
        bounds.x += computeSize(gCS[css]);
    });
    return bounds;
}

// Resultados:
// Firefox: gBCR: 142 - gCS: 400px - bBox: 363
// Chrome:  gBCR: 400 - gCS: 400px - bBox: 363 

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