False positives

[jonathantneal]

False positives

[jonathantneal]

Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/44.0.2403.155 Safari/537.36

That User Agent string does not pass the regex test.

Could you setup a test page?

[liamness]

Thanks for the quick reply. I'm using your polyfill in my blog and I've tried to set it up with 2.0.0 so I can support MS Edge.

[jdalton]

I've been kicking around a feature test that works for most
(except Safari so that could reduce the UA sniffing):

var polycheck = false;

;(function() {
  function check(e) {
    polycheck = use.getBoundingClientRect().width === 1;
    if (e || !--retries) {
      body.removeChild(svg);
      clearInterval(id);
    }
  }

  try {
    var url = URL.createObjectURL(
      new Blob([
        '<svg xmlns="http://www.w3.org/2000/svg">' +
        '<rect width="1" height="1" id="x"/>' +
        '</svg>'
      ], { 'type': 'image/svg+xml' })
    );

    var body = document.body;
    body.insertAdjacentHTML('beforeend',
      '<svg style="position:absolute;visibility:hidden">' +
      '<use xlink:href="' + url + '#x"/>' +
      '</svg>'
    );

    var retries = 3,
        svg = body.lastChild,
        use = svg.firstChild,
        id = setInterval(check, 50);

    use.addEventListener('load', check);
  } catch(e) {}
}());

[liamness]

I changed my build process to include the unminified version, so I could step through the code... and I can't replicate the bug anymore. I don't understand why but it all seems to work fine now, so I'm closing the issue. Thanks for taking a look.

[patrickkettner]

@jdalton wanna open that up on modernizr?

[gregwhitworth]

Looking at this code, I think it can be simplified and possibly address some coverage for interop differences/bugs by changing 1 to 0, since the external resource was accessed, thus the feature does work.

polycheck = use.getBoundingClientRect().width != 0;

Any issues with this approach? This now results in Chrome/Edge/Firefox all returning true, IE11 returning false.

[jpdevries]

@gregwhitworth Hm, I'm getting false with this in Safari 10.0.1

var polycheck = false;

;(function() {
  function check(e) {
    polycheck = use.getBoundingClientRect().width != 0;
    if (e || !--retries) {
      body.removeChild(svg);
      clearInterval(id);
    }
  }

  try {
    var url = URL.createObjectURL(
      new Blob([
        '<svg xmlns="http://www.w3.org/2000/svg">' +
        '<rect width="1" height="1" id="x"/>' +
        '</svg>'
      ], { 'type': 'image/svg+xml' })
    );

    var body = document.body;
    body.insertAdjacentHTML('beforeend',
      '<svg style="position:absolute;visibility:hidden">' +
      '<use xlink:href="' + url + '#x"/>' +
      '</svg>'
    );

    var retries = 3,
        svg = body.lastChild,
        use = svg.firstChild,
        id = setInterval(check, 50);

    use.addEventListener('load', check);
  } catch(e) {}
}());