Simple documents, templates and helpers on top of Prawn.
Because writing Prawn documents PHP 4 style is no fun.
If you're using this with Ruby on Rails, get PrawnCocktailRails
.
Ruby 1.9 only since we use and love instance_exec.
You can change where PrawnCocktail looks for its templates. This is the default (suitable for Ruby on Rails):
PrawnCocktail.template_root = "app/views/documents"
The document class provides a data hash for the template, and optionally a filename:
class InvoiceDocument < PrawnCocktail::Document
def initialize(invoice)
@invoice = invoice
end
def filename
"invoice_#{@invoice.id}.pdf"
end
private
def data
{
number: @invoice.id,
amount: @invoice.amount,
customer: { name: @invoice.customer_name }
}
end
end
In Ruby on Rails, we suggest putting this in app/documents/invoice_document.rb
. But anywhere is fine as long as the file is loaded, automatically or otherwise.
The document has render
and render_file(name)
methods, just like Prawn::Document
.
The filename is not required. Other libraries like PrawnCocktailRails
may make use of it.
The data
value is passed to the template as a recursive OpenStruct
-like object.
If the data becomes complex, you are advised to extract one or many builder classes like InvoiceDocument::Data
and call those from data
.
Put the Prawn code in a template in the PrawnCocktail.template_root
directory, named after the document, with a .pdf.rb
extension.
The defaults (suitable for Ruby on Rails) would make that e.g. app/views/documents/invoice_document.pdf.rb
.
meta page_size: "A4"
content do |data|
text "Invoice #{data.number}"
move_down 10
text "Amount: #{data.amount}"
move_down 10
text data.customer.name
end
The meta
declaration is optional. It takes a hash which will be passed to Prawn::Document.new
. This is where you specify page_size
, page_layout
and such.
The content
block will be passed the data from the document as a recursive OpenStruct
-type object (actually a RecursiveClosedStruct
utility class).
The content
block will be rendered in the context of a Prawn::Document
instance.
You are advised to extract any complexity or shared code out of the template and into helpers:
# Document
class InvoiceDocument
helper BaseDocumentHelper
helper InvoiceDocumentHelper
end
# Template
content do |data|
common_header
text "Yo."
end
# Helper
module BaseDocumentHelper
def common_header
text "Document generated #{Time.now}."
end
end
Any loaded module can be used as a helper, as long as its methods can run in the context of a Prawn document.
If you use PrawnCocktailRails
, you can put modules in app/documents/helpers
, e.g. app/documents/helpers/base_document_helper.rb
, and they will be autoloaded.
Note that you must explicitly declare the helpers you want. No helpers are automatically included. You can declare base helpers in a base document class, though, and they will be inherited.
If you want to run some code in every template, use an initialize_template
block:
class BaseDocument < PrawnCocktail::Document
initialize_template do
font "Courier"
end
end
This is incidentally how helpers are implemented:
def self.helper(mod)
initialize_template { extend mod }
end
You can have any number of template initializers, not just one.
Template initializers in a superclass are inherited by subclasses, and the subclass can add its own.
Add this line to your application's Gemfile:
gem 'prawn_cocktail'
And then execute:
$ bundle
Or install it yourself as:
$ gem install prawn_cocktail
Copyright (c) 2013 Barsoom AB
MIT License
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.