prawnpdf/prawn

# frozen_string_literal: true

require 'prawn/manual_builder'

Prawn::ManualBuilder::Chapter.new do
  title 'Creating a PDF Document'

  text do
    prose <<~TEXT
      There are three ways to create a PDF Document in Prawn: creating a new
      <code>Prawn::Document</code> instance, or using the
      <code>Prawn::Document.generate</code> method with and without block
      arguments.

      The following snippet showcase each way by creating a simple document with
      some text drawn.

      When we instantiate the <code>Prawn::Document</code> object the actual pdf
      document will only be created after we call <code>render_file</code>.

      The generate method will render the actual pdf object after exiting the
      block. When we use it without a block argument the provided block is
      evaluated in the context of a newly created <code>Prawn::Document</code>
      instance. When we use it with a block argument a
      <code>Prawn::Document</code> instance is created and passed to the block.

      The generate method without block arguments requires less typing and
      defines and renders the pdf document in one shot. Almost all of the
      examples are coded this way.
    TEXT
  end

  example eval: false, standalone: true do
    # Assignment
    pdf = Prawn::Document.new
    pdf.text('Hello World')
    pdf.render_file('assignment.pdf')

    # Implicit Block
    Prawn::Document.generate('implicit.pdf') do
      text 'Hello World'
    end

    # Explicit Block
    Prawn::Document.generate('explicit.pdf') do |pdf|
      pdf.text('Hello World')
    end
  end
end