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# frozen_string_literal: true
require 'prawn/manual_builder'
Prawn::ManualBuilder::Chapter.new do
title 'View'
text do
prose <<~TEXT
The recommended way to extend Prawn's functionality is to include the
<code>Prawn::View</code> mixin in your own class, which will make all
<code>Prawn::Document</code> methods available to your custom objects.
This approach is preferred over inheriting from
<code>Prawn::Document</code>, as your state will be kept completely
separate from <code>Prawn::Document</code>'s, thus avoiding accidental
method collisions.
Note that <code>Prawn::View</code> lazily instantiates a
<code>Prawn::Document</code> with default initialization settings, such
as page size, layout, margins, etc.
By defining your own <code>document</code> method you will be able to
override those settings and initialize a <code>Prawn::Document</code> to
your heart's content. This method will be called repeatedly by
<code>Prawn::View</code>, so be sure to memoize the object by assigning
it to an instance variable via the <code>||=</code> operator.
TEXT
end
# rubocop: disable Lint/ConstantDefinitionInBlock
example eval: false, standalone: true do
class Greeter
include Prawn::View
def initialize(name)
@name = name
end
def document
@document ||= Prawn::Document.new(page_size: 'A4', margin: 30)
end
def say_hello
font('Courier') do
text("Hello, #{@name}!")
end
end
end
greeter = Greeter.new('Gregory')
greeter.say_hello
greeter.save_as('greetings.pdf')
end
# rubocop: enable Lint/ConstantDefinitionInBlock
end
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