Use prawn-rails instead of custom View Handler, refactor invoice

* Use prawn-rails
* Delete old view handler code
* Refactor invoice to partials
* Adjust table width so they're dynamic (and the template can also handle A4
* Refactor packaging slip, too
* Override prawn_rails' configuration

app/models/spree/invoice.rb

@@ -0,0 +1,106 @@
+class Spree::Invoice < ActiveRecord::Base
+  belongs_to :invoiceable, polymorphic: true
+  validates :invoiceable, presence: true
+
+  before_save :set_date
+  before_save :set_number, if: :use_sequential_number?
+  after_save :increase_invoice_number, if: :use_sequential_number?
+
+  # Returns the given template as pdf binary suitable for Rails send_data
+  #
+  # If the file is already present it returns this
+  # else it generates a new file, stores and returns this.
+  #
+  # You can disable the pdf file generation with setting
+  #
+  #   Spree::PrintInvoice::Config.store_pdf to false
+  #
+  def pdf_file(template)
+    if Spree::PrintInvoice::Config.store_pdf
+      send_or_create_pdf(template)
+    else
+      render_pdf(template)
+    end
+  end
+
+  # = The PDF filename
+  #
+  # Tries to take invoice_number attribute.
+  # If this is not present it takes the order number.
+  #
+  def pdf_filename
+    number.present? ? number : invoiceable.number
+  end
+
+  # = PDF file path for template name
+  #
+  def pdf_file_path(template)
+    Rails.root.join(pdf_storage_path(template), "#{pdf_filename}.pdf")
+  end
+
+  # = PDF storage folder path for given template name
+  #
+  # Configure the storage path with +Spree::PrintInvoice::Config.storage_path+
+  #
+  # Each template type gets it own pluralized folder inside
+  # of +Spree::PrintInvoice::Config.storage_path+
+  #
+  # == Example:
+  #
+  #   pdf_storage_path('invoice') => "tmp/pdf_prints/invoices"
+  #
+  # Creates the folder if it's not present yet.
+  #
+  def pdf_storage_path(template)
+    storage_path = Rails.root.join(Spree::PrintInvoice::Config.storage_path, template.pluralize)
+    FileUtils.mkdir_p(storage_path)
+    storage_path
+  end
+
+  # Renders the prawn template for give template name in context of ActionView.
+  #
+  # Prawn templates need to be placed in +app/views/spree/admin/invoices/+ folder.
+  #
+  # Assigns +@invoice+ instance variable
+  #
+  def render_pdf(template)
+    ActionView::Base.new(
+      ActionController::Base.view_paths,
+      {invoice: self, template: template}
+    ).render(template: "spree/admin/invoices/#{template}.pdf.prawn")
+  end
+
+  private
+
+  # Sends stored pdf for given template from disk.
+  #
+  # Renders and stores it if it's not yet present.
+  #
+  def send_or_create_pdf(template)
+    file_path = pdf_file_path(template)
+
+    unless File.exist?(file_path)
+      File.open(file_path, 'wb') { |f| f.puts render_pdf(template) }
+    end
+
+    IO.binread(file_path)
+  end
+
+  ### AR Callback actions
+
+  def set_date
+    self.date ||= Date.today
+  end
+
+  def set_number
+    self.number ||= Spree::PrintInvoice::Config.next_number
+  end
+
+  def increase_invoice_number
+    Spree::PrintInvoice::Config.increase_invoice_number!
+  end
+
+  def use_sequential_number?
+    @_use_sequential_number ||= Spree::PrintInvoice::Config.use_sequential_number?
+  end
+end

app/models/spree/order_decorator.rb

@@ -95,7 +95,7 @@ def send_or_create_pdf(template)
     file_path = pdf_file_path(template)
 
     unless File.exist?(file_path)
-      File.open(file_path, "wb") { |f| f.puts render_pdf(template) }
+      File.open(file_path, 'wb') { |f| f.puts render_pdf(template) }
     end
 
     IO.binread(file_path)

app/views/spree/admin/invoices/_address_block.pdf.prawn

@@ -0,0 +1,25 @@
+bill_address = invoice.invoiceable.bill_address
+ship_address = invoice.invoiceable.ship_address
+
+pdf.move_down 2
+address_cell_billing  = pdf.make_cell(content: Spree.t(:billing_address), font_style: :bold)
+address_cell_shipping = pdf.make_cell(content: Spree.t(:shipping_address), font_style: :bold)
+
+billing =  "#{bill_address.firstname} #{bill_address.lastname}"
+billing << "\n#{bill_address.address1}"
+billing << "\n#{bill_address.address2}" unless bill_address.address2.blank?
+billing << "\n#{bill_address.city}, #{bill_address.state_text} #{bill_address.zipcode}"
+billing << "\n#{bill_address.country.name}"
+billing << "\n#{bill_address.phone}"
+
+shipping =  "#{ship_address.firstname} #{ship_address.lastname}"
+shipping << "\n#{ship_address.address1}"
+shipping << "\n#{ship_address.address2}" unless ship_address.address2.blank?
+shipping << "\n#{ship_address.city}, #{ship_address.state_text} #{ship_address.zipcode}"
+shipping << "\n#{ship_address.country.name}"
+shipping << "\n#{ship_address.phone}"
+shipping << "\n\n#{Spree.t(:via, scope: :print_invoice)} #{@invoice.invoiceable.shipments.first.shipping_method.name}"
+
+data = [[address_cell_billing, address_cell_shipping], [billing, shipping]]
+
+pdf.table(data, position: :center, column_widths: [pdf.bounds.width / 2, pdf.bounds.width / 2])

app/views/spree/admin/invoices/_footer.pdf.prawn

@@ -0,0 +1,14 @@
+pdf.repeat(:all) do
+  pdf.grid([7,0], [7,4]).bounding_box do
+
+    data  = []
+    data << [pdf.make_cell(content: Spree.t(:vat, scope: :print_invoice), colspan: 2, align: :center)]
+    data << [pdf.make_cell(content: '', colspan: 2)]
+    data << [pdf.make_cell(content: Spree::PrintInvoice::Config[:footer_left],  align: :left),
+    pdf.make_cell(content: Spree::PrintInvoice::Config[:footer_right], align: :right)]
+
+    pdf.table(data, position: :center, column_widths: [pdf.bounds.width / 2, pdf.bounds.width / 2]) do
+      row(0..2).style borders: []
+    end
+  end
+end

app/views/spree/admin/invoices/_header.pdf.prawn

@@ -0,0 +1,22 @@
+im = Rails.application.assets.find_asset(Spree::PrintInvoice::Config[:logo_path])
+
+if im && File.exist?(im.pathname)
+  pdf.image im, vposition: :top, height: 40, scale: Spree::PrintInvoice::Config[:logo_scale]
+end
+
+pdf.grid([0,3], [1,4]).bounding_box do
+  pdf.text Spree.t(template.to_sym, scope: :print_invoice), align: :right, style: :bold, size: 18
+  pdf.move_down 4
+
+  pdf.text I18n.l(invoice.invoiceable.completed_at.to_date), align: :right if invoice.invoiceable.completed_at?
+
+  if Spree::PrintInvoice::Config.use_sequential_number? && invoice.number.present?
+    pdf.text Spree.t(:invoice_number, number: invoice.number), align: :right
+    pdf.move_down 2
+    pdf.text "#{Spree.t(:invoice_date, scope: :print_invoice)} #{I18n.l invoice.date}", align: :right
+  else
+    pdf.text Spree.t(:order_number, number: invoice.invoiceable.number), align: :right
+    pdf.move_down 2
+    pdf.text I18n.l(invoice.invoiceable.completed_at.to_date), align: :right
+  end
+end

app/views/spree/admin/invoices/_invoice_items.pdf.prawn

@@ -0,0 +1,29 @@
+header = [
+  pdf.make_cell(content: Spree.t(:sku)),
+  pdf.make_cell(content: Spree.t(:item_description)),
+  pdf.make_cell(content: Spree.t(:options)),
+  pdf.make_cell(content: Spree.t(:price)),
+  pdf.make_cell(content: Spree.t(:qty)),
+  pdf.make_cell(content: Spree.t(:total))
+]
+data = [header]
+
+invoice.invoiceable.line_items.each do |item|
+  row = [
+    item.variant.sku,
+    item.variant.name,
+    item.variant.options_text,
+    item.single_display_amount.to_s,
+    item.quantity,
+    item.display_total.to_s
+  ]
+  data += [row]
+end
+
+column_widths = [0.13, 0.37, 0.185, 0.12, 0.075, 0.12].map { |w| w * pdf.bounds.width }
+
+pdf.table(data, header: true, position: :center, column_widths: column_widths) do
+  row(0).style align: :center, font_style: :bold
+  column(0..2).style align: :left
+  column(3..6).style align: :right
+end

app/views/spree/admin/invoices/_packaging_slip_items.pdf.prawn

@@ -0,0 +1 @@
+_packaging_slip_items

app/views/spree/admin/invoices/_page_number.pdf.prawn

@@ -0,0 +1,11 @@
+string  = "#{Spree.t(:page, scope: :print_invoice)} <page> #{Spree.t(:of, scope: :print_invoice)} <total>"
+
+options = {
+  at: [pdf.bounds.right - 155, 0],
+  width: 150,
+  align: :right,
+  start_count_at: 1,
+  color: '000000'
+}
+
+pdf.number_pages string, options

app/views/spree/admin/invoices/_totals.pdf.prawn

@@ -0,0 +1,40 @@
+# TOTALS
+totals = []
+
+# Subtotal
+totals << [pdf.make_cell(content: Spree.t(:subtotal)), invoice.invoiceable.display_item_total.to_s]
+
+# Adjustments
+invoice.invoiceable.all_adjustments.eligible.each do |adjustment|
+  totals << [pdf.make_cell(content: adjustment.label), adjustment.display_amount.to_s]
+end
+
+# Shipments
+invoice.invoiceable.shipments.each do |shipment|
+  totals << [pdf.make_cell(content: shipment.shipping_method.name), shipment.display_cost.to_s]
+end
+
+# Totals
+totals << [pdf.make_cell(content: Spree.t(:order_total)), invoice.invoiceable.display_total.to_s]
+
+# Payments
+total_payments = 0.0
+invoice.invoiceable.payments.each do |payment|
+  totals << [
+    pdf.make_cell(
+      content: Spree.t(:payment_via,
+      gateway: (payment.source_type || Spree.t(:unprocessed, scope: :print_invoice)),
+      number: payment.number,
+      date: I18n.l(payment.updated_at.to_date, format: :long),
+      scope: :print_invoice)
+    ),
+    payment.display_amount.to_s
+  ]
+  total_payments += payment.amount
+end
+
+totals_table_width = [0.875, 0.125].map { |w| w * pdf.bounds.width }
+pdf.table(totals, column_widths: totals_table_width) do
+  row(0..6).style align: :right
+  column(0).style borders: [], font_style: :bold
+end