Run wkhtmltopdf With Chinese Font Support on Travis CI

Run wkhtmltopdf on Travis CI, which convert HTML files with chinese characters to PDF.

We need to overcome the following two problems:

1. error message: wkhtmltopdf: cannot connect to X server

   The solution comes from this answer on Stack Overflow. Add the following lines in your .travis.yml

   sudo: required
   dist: trusty
   before_install:
   - sudo apt-get -qq update
   - sudo apt-get install -y xfonts-75dpi
   - wget http://download.gna.org/wkhtmltopdf/0.12/0.12.2/wkhtmltox-0.12.2_linux-trusty-amd64.deb
   - sudo dpkg -i wkhtmltox-0.12.2_linux-trusty-amd64.deb
   

2. wkhtmltopdf Chinese character support

   The solution comes from this blog post. Add the following lines in your .travis.yml

   before_install:
   - sudo apt-get install -y language-pack-zh-hant fonts-wqy-microhei ttf-wqy-microhei fonts-wqy-zenhei ttf-wqy-zenhei
   install:
   - fc-cache -f -v
   

Combine the above two solution together, your final .travis.yml will looks like:

sudo: required
dist: trusty
before_install:
- sudo apt-get -qq update
- sudo apt-get install -y language-pack-zh-hant fonts-wqy-microhei ttf-wqy-microhei fonts-wqy-zenhei ttf-wqy-zenhei
- sudo apt-get install -y xfonts-75dpi
- wget http://download.gna.org/wkhtmltopdf/0.12/0.12.2/wkhtmltox-0.12.2_linux-trusty-amd64.deb
- sudo dpkg -i wkhtmltox-0.12.2_linux-trusty-amd64.deb
install:
- fc-cache -f -v

Example Bash script to run wkhtmltopdf:

#!/bin/bash

# $1 is the directory in which files to be processed
# $2 is the css file
for path in $(find $1 -name "*.html")
do
  echo -e "\033[92mProcessing ${path}\033[0m"
  wkhtmltopdf ${path} --disable-javascript --user-style-sheet $2 "${path%.html}.pdf"
done

Tested on: Travis CI - The Trusty beta Build Environment, http://download.gna.org/wkhtmltopdf/0.12/0.12.2/wkhtmltox-0.12.2_linux-trusty-amd64.deb

References: