WkHtmlToPdf for Crystal - PROJECT UNMAINTAINED

This project is not maintained anymore

If you like it or continue to use it fork it please.

Crystal wrapper for libwkhtmltox C library.

wkhtmltopdf and wkhtmltoimage permit to render HTML into PDF and various image formats using the Qt WebKit rendering engine - see wkhtmltopdf.org

Requirements

libwkhtmltox must be installed
pkg-config must be available

Installation

Add this to your application's shard.yml:

dependencies:
  wkhtmltopdf-crystal:
    github: blocknotes/wkhtmltopdf-crystal

If wkhtmltox library is installed but missing for Crystal compiler: copy wkhtmltox.pc (from lib/wkhtmltopdf-crystal folder) in a pkg-config folder (ex. /usr/local/lib/pkgconfig) or set the environment variable PKG_CONFIG_PATH with the path to wkhtmltox.pc before compiling
Optinally edit wkhtmltox.pc with the correct path to wkhtmltox (default headers path: /usr/local/include/wkhtmltox)

Usage

HTML to PDF:

require "wkhtmltopdf-crystal"
Wkhtmltopdf::WkPdf.new( "test.pdf" ).convert( "<h3>Just a test</h3>" )

Fetch URL content and convert it to JPG:

require "wkhtmltopdf-crystal"
img = Wkhtmltopdf::WkImage.new
img.set_url "http://www.google.com"
img.set_output "test.jpg"
img.set "quality", "90"
img.convert

Write to buffer (only if no output is specified):

require "wkhtmltopdf-crystal"
pdf = Wkhtmltopdf::WkPdf.new
pdf.convert "<h3>Just a test</h3>"
pdf.object_setting "footer.right", "[page] / [topage]" # Set page counter on footer
unless pdf.buffer.nil?
  puts "PDF buffer size: " + pdf.buffer.try( &.size ).to_s
end

Lib settings (available with set / object_setting methods on wrappers): libwkhtmltox pagesettings

More examples

See examples folder. Includes a Kemal example to print an ECR view in PDF.

Troubleshooting

Invalid memory access

If this component needs to be called multiple times it's necessary to initialize the library in the constructor and call deinitialize when all is done. Example:

require "wkhtmltopdf-crystal"
pdf = Wkhtmltopdf::WkPdf.new "", true
at_exit do
  pdf.deinitialize
end

pdf.set_output "test1.pdf"
pdf.convert "<h3>Just a test 1</h3>"

pdf.set_output "test2.pdf"
pdf.convert "<h3>Just a test 2</h3>"

Contributors

Mattia Roccoberton - creator, maintainer

yrgoldteeth/wkhtmltopdf-crystal