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Published May 26, 2012 Updated January 7, 2022
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Prawn+

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Prawn+ is a lightweight Rails Engine that wraps the Prawn PDF generator in order to render PDFs within Rails views. This allows you to build view templates which render PDFs using the Prawn syntax.

Features

  • Loads the Prawn gem by default (no Gemfile entry necessary).

  • Registers PDF as a MIME type.

  • Registers a template handler for rendering “.prawn” template view files.

Requirements

Setup

To install, run:

gem install prawn_plus

Add the following to your Gemfile:

gem "prawn_plus"

Usage

Views

Within your views you can craft Prawn templates using Ruby code. For example, assuming there are document resources, then the following structure might exist:

/views/documents/show.html.slim
/views/documents/show.pdf.prawn

The show.html.slim could have a link to the PDF download. Example:

= link_to "PDF Download", action: "show", id: @document.id, format: "pdf"

The show.pdf.prawn file would contain the Prawn syntax for crafting the PDF. A simple example might look like this:

pdf.text "Hello, I'm a PDF!"

…​which would render the following output:

Basic Example

You could also render a more complex PDF with tabular information, for example:

pdf.text "Metals"
pdf.move_down 10
pdf.font_size = 10

data = [
  ["Name", "Atomic Number", "Price"],
  ["Mercury", "80", number_to_currency(10)],
  ["Platinum", "78", number_to_currency(25)],
  ["Titanium", "22", number_to_currency(50)]
]

pdf.table data, header: true, column_widths: [100, 50, 50], row_colors: ["FFFFFF", "E5ECF9"] do
  columns(0).align = :left
  columns(1..2).align = :right
  row(0).text_color = "FFFFFF"
  row(0).background_color = "000000"
  row(0).columns(0..2).font_style = :bold
  row(0).columns(0..2).align = :center
end

…​which would render the following output:

Complex Example

NOTE: The pdf object must always be referenced when making using of the Prawn syntax - it is initialized for you as a Prawn::Document instance.

Controllers

Within your controller, only the respond_to method is required. Example:

class DocumentsController < ApplicationController
  respond_to :pdf

  def show
  end
end

That’s it!

Development

To contribute, run:

git clone https://github.com/bkuhlmann/prawn_plus.git
cd prawn_plus
bin/setup

You can also use the IRB console for direct access to all objects:

bin/console

Tests

To test, run:

bundle exec rake

Credits