Module: EchoUploads::PrmFileWriting::ClassMethods

Defined in:
lib/echo_uploads/prm_file_writing.rb

Instance Method Summary collapse

Instance Method Details

#echo_uploads_configure_prm_file_writing(attr, options) ⇒ Object 



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# File 'lib/echo_uploads/prm_file_writing.rb', line 6

def echo_uploads_configure_prm_file_writing(attr, options)
  # Save the file and the metadata after this model saves.
  after_save do |model|
    @echo_uploads_prm_files_saved ||= {}
    if (file = send(attr)).present? and @echo_uploads_prm_files_saved[attr.to_sym] != file
      # A file is being uploaded during this request cycle. Further, we have not
      # already done the permanent file saving during this request cycle. (It's
      # not uncommon for a model to be saved twice in one request. If we ran this
      # code twice, we'd have duplicate effort at best and exceptions at worst.)
      
      @echo_uploads_prm_files_saved[attr.to_sym] = file
      
      if options[:multiple]
        metas = send("#{attr}_metadatas")
      else
        metas = [send("#{attr}_metadata")].compact
      end
      
      # metas is now an array of ::EchoUploads::File instances. The array may
      # be empty.
      
      if metas.any?
        # Previous permanent file(s) exist. This is a new version being uploaded.
        # Delete the old version(s).
        metas.each(&:destroy)
      end
      
      # No previous permanent files exists. The metas array is currently empty or
      # else contains deleted records. We need to rebuild that array by constructing
      # (but not yet saving) new EchoUploads::File objects.
      
      if options[:multiple]
        mapped_files = send("mapped_#{attr}") ||
          raise('echo_uploads called with :multiple, but :map option was missing')
        metas = mapped_files.map do |mapped_file|
          ::EchoUploads::File.new(
            owner: model, temporary: false, file: mapped_file
          )
        end
        send("#{attr}_metadatas=", metas)
      elsif options[:map]
        mapped_files = send("mapped_#{attr}")
        metas = [::EchoUploads::File.new(
          owner: model, temporary: false, file: mapped_files.first
        )]
        send("#{attr}_metadata=", metas.first)
      else
        metas = [::EchoUploads::File.new(
          owner: model, temporary: false, file: send(attr)
        )]
        send("#{attr}_metadata=", metas.first)
      end
      
      # metas is still an array of the EchoUploads::File instances. If the array was
      # initially empty (meaning no previous permanent file existed), then it has
      # since been populated.
      
      metas.each do |meta|
        meta.persist! attr, options
      end
    elsif metas = send("#{attr}_tmp_metadata")
      # A file has not been uploaded during this request cycle. However, the
      # submitted form "remembered" a temporary metadata record that was previously
      # saved.
      
      # Delete any existing metadata record. (It's possible we
      # were trying to replace an old version of the file, and there were validation
      # errors on the first attempt.)
      
      if options[:multiple]
        model.send("#{attr}_metadatas").each(&:destroy)
      elsif old = model.send("#{attr}_metadata")
        old.destroy
      end
      
      # We need not call persist! here, because the file is already persisted. (Nor
      # could we call it, because persist! requires an
      # ActionDispatch::HTTP::UploadedFile.) Mark the metadata record as permanent
      # and set its owner.
      metas.each do |meta|
        meta.owner = model
        meta.temporary = false
        meta.expires_at = nil
        meta.save!
      end
      
      if options[:multiple]
        send("#{attr}_metadatas=", metas)
      else
        send("#{attr}_metadata=", metas.first)
      end
    end
  end
end