A view object based architecture for printing arbitrary objects

Through clever naming of attributes and delegates, all integration tests
are still green. Orders will have the exact same API as before.

* Move invoice rendering methods to Spree::BookkeepingDocument
* Add view objects to connect Spree Objects with Spree::BookkeepingDocument

Your PDF template should be agnostic about the structure of your
printable object. The view objects achieve that.

* Improve NotImplementeError messages
* Add item and adjustment POROs, invoices controller
* Add order#documents tab, translations
* Fix feature spec: Documents tab instead of print buttons
* Rrename all the partials
* Rename "file" to "pdf"
* Add a working index action to the PdfsController
* Fix specs accordingly
* Remove selecting template feature

Before, you were able to select a template from the backend.

As it is considerable development effort to create a Prawn template,
I think it makes sense to remove this option from the user. Now, there's
a PDF model, and you can create a new PDF by creating it with the underlying
Object as `printable` and a string specifying the template to be used.

* First version of index.html.erb
* Make BookkeepingDocument model searchable
* Move invoice number logic to Spree::BookkeepingDocument
* Add a base view that complains when essential things are not defined on a view
* Mmove increasing invoice numbers to base invoice view
* Tests for deprecated methods on Spree::Order
* Use order number for order packaging slip

README.md

@@ -3,7 +3,18 @@
 [![Build Status](https://travis-ci.org/spree-contrib/spree_print_invoice.svg?branch=master)](https://travis-ci.org/spree-contrib/spree_print_invoice)
 [![Code Climate](https://codeclimate.com/github/spree-contrib/spree_print_invoice/badges/gpa.svg)](https://codeclimate.com/github/spree-contrib/spree_print_invoice)
 
-This extension provides a "Print Invoice" button (per default) on the Admin Orders view screen which generates a PDF of the order details. It's fully extendable so you can add own _print slips_ from your own Rails app. It also comes with a packaging slip.
+This extension provides two things:
+
+ * A model `Spree::Invoice`, which is generated when an order is completed or a reimbursement is created. It holds a date and a contiguous invoice number to comply with European tax regulation.
+ * A model `Spree::BookkeepingDocument`, which generates PDFs from any Spree Object with the help of View objects that translate between different object structures and PDF templates.
+
+The Gem contains example implementations for Invoices for `Spree::Order` as well as `Spree::Reimbursement`. The basic structure looks like this:
+
+`Spree::BookkeepingDocument` takes as constructor arguments a `printable` (polymorphic AR object) and a `template` (string). It then passes on all actual data generation to a ViewObject. You can find these objects in `app/spree/printables/#{printable}/#{template}_view.rb`. The object will be instantiated upon PDF generation (look at the `Spree::BookkeepingDocument#render_pdf` method to see how it's done).
+
+`Spree::Order` and `Spree::Reimbursement` are patched so that they generate both an invoice number and date and a PDF.
+
+In the `Spree::Admin::OrdersController#show` view, you'll find an additional button `Documents`, where all printable documents will be listed.
 
 ## Installation
 
@@ -17,7 +28,7 @@ Run
 bundle && exec rails g spree_print_invoice:install
 ```
 
-Enjoy! Now allow to generate invoices with sequential numbers.
+Enjoy! Now you can generate invoices and packaging slips with sequential numbers from arbitrary Spree objects.
 
 ---
 
@@ -33,31 +44,21 @@ Enjoy! Now allow to generate invoices with sequential numbers.
 
 3. Override any of the partial templates. They are address, footer, totals, header, bye, and the line_items. In bye the text `:thanks` is printed. The `:extra_note` hook has been deprecated as Spree no longer supports hooks.
 
-4. Set `:suppress_anonymous_address` option to get blank addresses for anonymous email addresses (as created by my spree_last_address extension for empty/unknown user info).
-
-5. Many european countries requires numeric and sequential invoices numbers. To use invoices sequential number fill the specific field in "General Settings" or by setting:
+4. Many european countries requires numeric and sequential invoices numbers. To use invoices sequential number fill the specific field in "General Settings" or by setting:
 
   ```ruby
   Spree::PrintInvoice::Config.set(next_number: [1|'your current next invoice number'])
   ```
 
   The next invoice number will be the one that you specified. You will able to increase it in any moment, for example, to re-sync invoices number if you are making invoices also in other programs for the same business name.
 
-6. Enable packaging slips, by setting:
-
-  ```ruby
-  Spree::PrintInvoice::Config.set(print_buttons: 'invoice,packaging_slip') # comma separated list
-  ```
-
-  Use above feature for your own template if you want. For each button_name, define `button_name_print` text in your locale.
-
-7. Set page/document options with:
+5. Set page/document options with:
 
   ```ruby
   Spree::PrintInvoice::Config.set(prawn_options: { page_layout: :landscape, page_size: 'A4', margin: [50, 100, 150, 200] })
   ```
 
-8. Enable PDF storage feature
+6. Enable PDF storage feature
 
   PDF files can be stored to disk. This is very handy, if you want to send these files as email attachment.
 
@@ -76,7 +77,11 @@ In order to customize the build in invoice and packaging slip templates you need
 $ bundle exec rails g spree_print_invoice:templates
 ```
 
-You can then customize them at `app/views/spree/admin/orders/invoice.pdf.prawn` and `app/views/spree/admin/orders/packaging_slip.pdf.prawn`.
+You can then customize them at the following locations:
+
+ * `app/views/spree/printables/order/invoice.pdf.prawn`
+ * `app/views/spree/printables/reimbursement/invoice.pdf.prawn`
+ * `app/views/spree/printables/order/packaging_slip.pdf.prawn`.
 
 ---
 

app/controllers/spree/admin/bookkeeping_documents_controller.rb

@@ -0,0 +1,36 @@
+module Spree
+  module Admin
+    class BookkeepingDocumentsController < ResourceController
+      before_action :load_order, if: :order_focused?
+
+      helper_method :order_focused?
+
+      def show
+        respond_with(@bookkeeping_document) do |format|
+          format.pdf do
+            send_data @bookkeeping_document.pdf, type: 'application/pdf', disposition: 'inline'
+          end
+        end
+      end
+
+      def index
+        # Massaging the params for the index view like Spree::Admin::Orders#index
+        params[:q] ||= {}
+        @search = Spree::BookkeepingDocument.ransack(params[:q])
+        @bookkeeping_documents = @search.result
+        @bookkeeping_documents = @bookkeeping_documents.where(printable: @order) if order_focused?
+        @bookkeeping_documents = @bookkeeping_documents.page(params[:page] || 1).per(10)
+      end
+
+      private
+
+      def order_focused?
+        params[:order_id].present?
+      end
+
+      def load_order
+        @order = Spree::Order.find_by(number: params[:order_id])
+      end
+    end
+  end
+end

app/models/spree/bookkeeping_document.rb

@@ -0,0 +1,149 @@
+module Spree
+  class BookkeepingDocument < ActiveRecord::Base
+    PERSISTED_ATTRS = [
+      :firstname,
+      :lastname,
+      :email,
+      :total,
+      :number
+    ]
+
+    # Spree::BookkeepingDocument cares about creating PDFs. Whenever it needs to know
+    # anything about the document to send to the view, it asks a view object.
+    #
+    # +printable+ should be an Object, such as Spree::Order or Spree::Shipment.
+    # template should be a string, such as "invoice" or "packaging_slip"
+    #
+    belongs_to :printable, polymorphic: true
+    validates :printable, :template, presence: true
+    validates *PERSISTED_ATTRS, presence: true, if: -> { self.persisted? }
+    scope :invoices, -> { where(template: 'invoice') }
+
+    before_create :copy_view_attributes
+    after_save :after_save_actions
+
+
+    # An instance of Spree::Printable::#{YourModel}::#{YourTemplate}Presenter
+    #
+    def view
+      @_view ||= view_class.new(printable)
+    end
+
+    def date
+      created_at.to_date
+    end
+
+    def template_name
+      "spree/printables/#{single_lower_case_name(printable.class.name)}/#{template}"
+    end
+
+    # If the document is called from the view with some method it doesn't know,
+    # just call the view object. It should know.
+    def method_missing(method_name, *args, &block)
+      if view.respond_to? method_name
+        view.send(method_name, *args, &block)
+      else
+        super
+      end
+    end
+
+    def document_type
+      "#{printable_type.demodulize.tableize.singularize}_#{template}"
+    end
+
+    # 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
+      if Spree::PrintInvoice::Config.store_pdf
+        send_or_create_pdf
+      else
+        render_pdf
+      end
+    end
+
+    # = The PDF file_name
+    #
+    def file_name
+      @_file_name ||= "#{template}-#{printable.number}.pdf"
+    end
+
+    # = PDF file path
+    #
+    def file_path
+      @_file_path ||= Rails.root.join(storage_path, "#{file_name}")
+    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:
+    #
+    #   storage_path('invoice') => "tmp/pdf_prints/invoices"
+    #
+    # Creates the folder if it's not present yet.
+    #
+    def storage_path
+      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 the correct folder. For example, for a PDF from
+    # a Spree::Order with the invoice template, it would be
+    # the +app/views/spree/printables/order/invoices+ folder.
+    #
+    # Assigns +@doc+ instance variable
+    #
+    def render_pdf
+      ActionView::Base.new(
+        ActionController::Base.view_paths,
+        {doc: self}
+      ).render(template: "#{template_name}.pdf.prawn")
+    end
+
+    private
+
+    def copy_view_attributes
+      PERSISTED_ATTRS.each do |attr|
+        self.send("#{attr}=", view.send(attr))
+      end
+    end
+
+    # For a Spree::Order printable and an "invoice" template,
+    # you would get "spree/documents/order/invoice_view"
+    # --> Spree::Printables::Order::InvoiceView
+    #
+    def view_class
+      @_view_class ||= "#{template_name}_view".classify.constantize
+    end
+
+    def single_lower_case_name(class_string)
+      @_single_lower_class_name ||= class_string.demodulize.tableize.singularize
+    end
+
+    # Sends stored pdf for given template from disk.
+    #
+    # Renders and stores it if it's not yet present.
+    #
+    def send_or_create_pdf
+      unless File.exist?(file_path)
+        File.open(file_path, 'wb') { |f| f.puts render_pdf }
+      end
+
+      IO.binread(file_path)
+    end
+  end
+end