Renaming fonts to solve Multiple @font-face rules issue with wkhtmltopdf

A tool for Renaming fonts to solve Multiple font-face rules issue with wkhtmltopdf.md

The Problem

wkhtmltopdf is broken and cannot render multiple fonts because of some issues around names. See wkhtmltopdf/wkhtmltopdf#2435

Workaround

1. Pick an 8 or less char name for each font and variation e.g. HelvBold, HelvLite, TimeReg
2. Every variation needs to be a separate font file, with all the details renamed in Font Forge using the short name determined before.
3. Give the font files the same short name (e.g. HelvBold.ttf)
4. Setup the font-family with the same:

Rename Fonts

To rename a font use the rename_font.fs script attached to this gist with the original font name and the new shortfont as arguments.

rename_font.fs SuperFont-Book.otf BookSupr

rename_font.fs

#!/usr/local/bin/fontforge
Open($1)

# Language choice 
#
# Primary Language	Locale Name	LCID		Win CP	OEM CP
# English (6):		American	(0409; ENU)	1252	437

# Nameid
# 
# http://partners.adobe.com/public/developer/opentype/index_name.html#enc4
# 
# ID FIELD
# 1  Family
# 2  Sub-Family - Same as Family because default font
# 4  Fullname
# 6  PostScript Name
# 16 Preferred Family

SetFontNames($2, $2, $2, 500)
SetTTFName(0x409,1,$2)
SetTTFName(0x409,2,$2)
SetTTFName(0x409,4,$2)
SetTTFName(0x409,6,$2)
SetTTFName(0x409,16,$2)

Generate("out/" + $2:r + ".ttf")

z_font.css

/* Include the file as a base64 URL */
@font-face {
  font-family: BookSupr;
  src: url(data:application/octet-stream;base64,{{b64file 'emails/pdf/fonts/BookSupr.ttf' }});
  font-weight: normal;
}

Thanks, for this snipped! It worked great, but I had to change line 20 of rename_font.fs from

SetFontNames($2, $2, $2, 500)

to

SetFontNames($2, $2, $2, "500")

to fix SetFontNames: Bad type for argument. Also the directory out should exist, otherwise save would fail, too.