mattstuehler mattstuehler - 6 months ago 57
CSS Question

CSS: Using raw svg in the URL parameter of a background-image in IE

So, I'm trying to do something like this:

div {
width: 100px;
height: 100px;
background-position: center center;
background-repeat: no-repeat;
background-size: 100px 100px;
background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='100' height='100' style='fill:red; stroke:none'><rect x='0' y='40' width='100' height='20' /><rect x='40' y='0' width='20' height='100' /></svg>");
}


See here: http://jsfiddle.net/trxkcx41/4/

This works beautifully in current versions Chrome, Safari (OS X and iOS), and Firefox. However, the SVG doesn't appear at all in IE 9, 10, or 11.

Is that because this is not supported in IE, or because I'm doing something wrong?

[UPDATE WITH SOLUTION]

Thanks to hungerstar, I've got this working. To summarize his recommendation, I needed to make the following changes:


  1. Change the data type from
    data:image/svg+xml;utf8
    to
    data:image/svg+xml;charset=utf8
    (i.e.,
    charset=
    is required)

  2. URL encode the svg. To minimize the URL-encoding, use
    '
    instead of
    "
    to enclose the attributes. So, in my case, only the
    <
    and
    >
    needed to be encoded.



To, ultimately, my CSS looked like this:

background-image: url("data:image/svg+xml;charset=utf8,%3Csvg xmlns='http://www.w3.org/2000/svg' width='100' height='100' style='fill:red; stroke:none' %3E%3Crect x='0' y='40' width='100' height='20' /%3E%3Crect x='40' y='0' width='20' height='100' /%3E%3C/svg%3E");

Answer

IE does appear to support using utf8 in a data URI, it's simply being more fussy about it. See this Codepen Blog Post for more details but here are the highlights:

The author points to RFC2397 and highlights:

data:[<mediatype>][;base64],<data>

The <mediatype> is an Internet media type specification (with optional parameters.) The appearance of ";base64" means that the data is encoded as base64. Without ";base64", the data (as a sequence of octets) is represented using ASCII encoding for octets inside the range of safe URL characters and using the standard %xx hex encoding of URLs for octets outside that range. If <mediatype> is omitted, it defaults to text/plain;charset=US-ASCII. As a shorthand, "text/plain" can be omitted but the charset parameter supplied.

  • Most browsers are lenient about the charset= string, but it's required for Internet Explorer. That means you need to use ;charset=utf8, instead of ;utf8,.
  • From above, "Without ";base64", the data (as a sequence of octets) is represented using ASCII encoding for octets inside the range of safe URL characters and using the standard %xx hex encoding of URLs for octets outside that range." Which means you will have to percent-encode characters that aren't URL-safe. For example, <svg> to %3Csvg%3E. You can minimize the amount of percent encoding that needs to be done by using single quotes ' instead of double quotes ".