Create JPGs using plain old HTML+CSS. Uses wkhtmltoimage on the backend which renders HTML using Webkit.
Heavily based on PDFKit.
gem install imgkit
- Automatic:
sudo imgkit --install-wkhtmltoimageinstall latest version into /usr/local/bin (overwrite defaults with e.g. ARCHITECTURE=amd64 TO=/home/foo/bin) - By hand: http://code.google.com/p/wkhtmltopdf/downloads/list
# IMGKit.new takes the HTML and any options for wkhtmltoimage
# run `wkhtmltoimage --extended-help` for a full list of options
kit = IMGKit.new(html, :quality => 50)
kit.stylesheets << '/path/to/css/file'
# Get the image BLOB
img = kit.to_img
# New in 1.3!
img = kit.to_img(:jpg) #default
img = kit.to_img(:jpeg)
img = kit.to_img(:png)
img = kit.to_img(:tif)
img = kit.to_img(:tiff)
# Save the image to a file
file = kit.to_file('/path/to/save/file.jpg')
file = kit.to_file('/path/to/save/file.png')
# IMGKit.new can optionally accept a URL or a File.
# Stylesheets can not be added when source is provided as a URL of File.
kit = IMGKit.new('http://google.com')
kit = IMGKit.new(File.new('/path/to/html'))
# Add any kind of option through meta tags
IMGKit.new('<html><head><meta name="imgkit-quality" content="75"...
# Format shortcuts - New in 1.3!
IMGKit.new("hello").to_jpg
IMGKit.new("hello").to_jpeg
IMGKit.new("hello").to_png
IMGKit.new("hello").to_tif
IMGKit.new("hello").to_tiff
Note: Ruby's buffered I/O means that if you want to write the string data to a file or tempfile make sure to call `#flush` to ensure the contents don't get stuck in the buffer.
If you're on Windows or you installed wkhtmltoimage by hand to a location other than /usr/local/bin you will need to tell IMGKit where the binary is. You can configure IMGKit like so:
# config/initializers/imgkit.rb
IMGKit.configure do |config|
config.wkhtmltoimage = '/path/to/wkhtmltoimage'
config.default_options = {
:quality => 60
}
config.default_format = :png
end
get a version of wkhtmltoimage as an amd64 binary and commit it
to your git repo. I like to put mine in "./bin/wkhtmltoimage-amd64"
assuming its in that location you can just do:
IMGKit.configure do |config|
config.wkhtmltoimage = Rails.root.join('bin', 'wkhtmltoimage-amd64').to_s if ENV['RACK_ENV'] == 'production'
end
If you're not using Rails just replace Rails.root with the root dir of your app.
register a .jpg mime type in:
#config/initializers/mime_type.rb
Mime::Type.register "image/jpeg", :jpg
register a .png mime type in:
#config/initializers/mime_type.rb
Mime::Type.register "image/png", :png
You can respond in a controller with:
@kit = IMGKit.new(render_to_string)
format.jpg do
send_data(@kit.to_jpg, :type => "image/jpeg", :disposition => 'inline')
end
- or -
format.png do
send_data(@kit.to_png, :type => "image/png", :disposition => 'inline')
end
- or -
respond_to do |format|
send_data(@kit.to_img(format.to_sym),
:type => "image/png", :disposition => 'inline')
end
This allows you to take advantage of rails page caching so you only generate the image when you need to.
To overcome the lack of support for --user-style-sheet option by wkhtmltoimage 0.10.0 rc2 as reported here http://code.google.com/p/wkhtmltopdf/issues/detail?id=387
require 'imgkit'
require 'restclient'
require 'stringio'
url = 'http://domain/path/to/stylesheet.css'
css = StringIO.new( RestClient.get(url) )
kit = IMGKit.new(<<EOD)
<!DOCTYPE HTML>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>coolest converter</title>
</head>
<body>
<div class="cool">image kit</div>
</body>
</html>
EOD
kit.stylesheets << css
Model:
class Model < ActiveRecord::Base
# attr_accessible :title, :body
has_attached_file :snapshot, :storage => :s3,
:s3_credentials => "#{Rails.root}/config/s3.yml"
endController:
def upload_image
model = Model.find(params[:id])
html = render_to_string
kit = IMGKit.new(html)
img = kit.to_img(:png)
file = Tempfile.new(["template_#{model.id}", 'png'], 'tmp',
:encoding => 'ascii-8bit')
file.write(img)
file.flush
model.snapshot = file
model.save
file.unlink
endContributed by @ticktricktrack
class MyClass < ActiveRecord::Base
mount_uploader :snapshot, SnapshotUploader
after_create :take_snapshot
# private
def take_snapshot
file = Tempfile.new(["template_#{self.id.to_s}", 'jpg'], 'tmp', :encoding => 'ascii-8bit')
file.write(IMGKit.new(self.html_body, quality: 50, width: 600).to_jpg)
file.flush
self.snapshot = file
self.save
file.unlink
end
end- Fork the project.
- Setup your development environment with: gem install bundler; bundle install
- Make your feature addition or bug fix.
- Add tests for it. This is important so I don't break it in a future version unintentionally.
- Commit, do not mess with rakefile, version, or history. (if you want to have your own version, that is fine but bump version in a commit by itself I can ignore when I pull)
- Send me a pull request. Bonus points for topic branches.
Copyright (c) 2010 Chris Continanza Based on work by Jared Pace See LICENSE for details.