How to embed Unicode Supplementary Private Use characters in CSS generated content?

Question

I'm using a webfont for icons. The icon glyphs are mapped to Unicode's Supplementary Private Use Area-A & B.

Everything works fine if I pass characters into CSS via data-* attributes:

<div class="icon" data-icon="&#xF005A;"></div>

And then:

.icon::before {
    font-family: IconFont;
    content: attr(data-icon)
}

But if I try to embed the escaped character directly in CSS...

.icon::before {
    font-family: IconFont;
    content: '\0F005A ';
}

It shows up as a missing symbol question mark.

But if I try a different special character...

.icon::before {
    font-family: IconFont;
    content: '\F8FF ';
}

It works fine!

I can't find anything in the spec that says this isn't possible... It just doesn't seem to work.

Anybody have any insight into this?

Answer 1

Visit Icomoon to map your icon font to Private Use Area. When you download the font, keyamoon has provided html, which has two methods for displaying the special characters.

Method 1 (from CSS-tricks) and included in Icomoon download:

<i aria-hidden="true" data-icon="&#xe000;"></i>

 ......

[data-icon]:before {
    font-family: 'icomoon';
    content: attr(data-icon);
    speak: none;
    font-weight: normal;
    font-variant: normal;
    text-transform: none;
    line-height: 1;
    -webkit-font-smoothing: antialiased;
}

Method 2 from Icomoon:

 <span aria-hidden="true" class="icon-pencil"></span>

 ......

.icon-pencil, .icon-folder {
    font-family: 'icomoon';
    speak: none;
    font-style: normal;
    font-weight: normal;
    font-variant: normal;
    text-transform: none;
    line-height: 1;
    -webkit-font-smoothing: antialiased;
}
.icon-pencil:before {
    content: "\e000";
}
.icon-folder:before {
    content: "\e001";
}

You can use any tag for the html really; I agree with one of the comments in CSS-tricks that the italic tag may be best semantically, since it was redefined in html5. I just like i for icon.