PDFs & screentshots for Rails using Ferrum & headless Chrome.
Inspired by Grover.
First, make sure Chrome is installed
Run the following or add the gem to your Gemfile:
bundle add "ferrum_pdf"
You can use FerrumPdf to render PDFs and Screenshots
There are two ways to render PDFs:
Use the render_pdf
helper in Rails controllers to render a PDF from the current action.
def show
respond_to do |format|
format.html
format.pdf {
pdf = render_pdf()
send_data pdf, disposition: :inline, filename: "example.pdf"
}
end
end
You can also customize which template is rendered. This will render the template to string with render_to_string
in Rails, then pass it along to Chrome. For example, you can add headers and footers using pdf_options
and use a specific layout:
render_pdf(
layout: "pdf,
pdf_options: {
display_header_footer: true,
header_template: FerrumPdf::DEFAULT_HEADER_TEMPLATE,
footer_template: FerrumPdf::DEFAULT_FOOTER_TEMPLATE
}
)
FerrumPdf can generate a PDF from HTML or a URL:
FerrumPdf.render_pdf(html: content)
FerrumPdf.render_pdf(url: "https://google.com")
You can also pass host and protocol to convert any relative paths to full URLs. This is helpful for converting relative asset paths to full URLs.
FerrumPdf.render_pdf(
html: content, # Provide HTML
url: "https://example.com", # or provide a URL to the content
host: request.base_url + "/", # Used for setting the host for relative paths
protocol: request.protocol, # Used for handling relative protocol paths
pdf_options: {
landscape: false, # paper orientation
scale: 1, # Scale of the webpage rendering
format: nil,
paper_width: 8.5, # Paper width in inches
paper_height: 11, # Paper height in inches
page_ranges: nil, # Paper ranges to print "1-5, 8 11-13"
# Margins (in inches, defaults to 1cm)
margin_top: 0.4,
margin_bottom: 0.4,
margin_left: 0.4,
margin_right: 0.4,
# Header, footer, and background options
#
# Variables can be used with CSS classes. For example <span class="date"></span>
# * date: formatted print date
# * title: document title
# * url: document location
# * pageNumber: current page number
# *totalPages: total pages in the document
display_header_footer: false,
print_background: false, # Print background graphics
header_template: "", # HTML template for the header
footer_template: "", # HTML template for the footer
}
)
See Chrome DevTools Protocol docs and Ferrum's #pdf
docs for the full set of options.
There are two ways to render Screenshots:
Use the render_screenshot
helper in Rails controllers to render a PDF from the current action.
def show
respond_to do |format|
format.html
format.png {
screenshot = render_screenshot()
send_data screenshot, disposition: :inline, filename: "example.png"
}
end
end
You can also customize which template is rendered. This will render the template to string with render_to_string
in Rails, then pass it along to Chrome.
render_screenshot(
screenshot_options: {
format: "png" # or "jpeg"
quality: nil # Integer 0-100 works for jpeg only
full: true # Boolean whether you need full page screenshot or a viewport
selector: nil # String css selector for given element, optional
area: nil # Hash area for screenshot, optional. {x: 0, y: 0, width: 100, height: 100}
scale: nil # Float zoom in/out
background_color: nil # Ferrum::RGBA.new(0, 0, 0, 0.0)
}
)
See Ferrum screenshot docs for the full set of options.
FerrumPdf can generate a screenshot from HTML or a URL:
FerrumPdf.render_screenshot(html: content)
FerrumPdf.render_screenshot(url: "https://google.com")
You can also pass host and protocol to convert any relative paths to full URLs. This is helpful for converting relative asset paths to full URLs.
FerrumPdf.render_screenshot(
html: "",
url: "",
root_url: "",
protocol: "",
screenshot_options: {
format: "png" # or "jpeg"
quality: nil # Integer 0-100 works for jpeg only
full: true # Boolean whether you need full page screenshot or a viewport
selector: nil # String css selector for given element, optional
area: nil # Hash area for screenshot, optional. {x: 0, y: 0, width: 100, height: 100}
scale: nil # Float zoom in/out
background_color: nil # Ferrum::RGBA.new(0, 0, 0, 0.0)
}
)
If you have an issue you'd like to submit, please do so using the issue tracker in GitHub. In order for us to help you in the best way possible, please be as detailed as you can.
The gem is available as open source under the terms of the MIT License.