Module: CarrierWave::Mongoid

Includes:
Mount
Defined in:
lib/carrierwave/mongoid.rb

Instance Method Summary collapse

Instance Method Details

#mount_uploader(column, uploader = nil, options = {}, &block) ⇒ Object

See CarrierWave::Mount#mount_uploader for documentation



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# File 'lib/carrierwave/mongoid.rb', line 14

def mount_uploader(column, uploader=nil, options={}, &block)
  field options[:mount_on] || column

  super

  alias_method :read_uploader, :read_attribute
  alias_method :write_uploader, :write_attribute
  public :read_uploader
  public :write_uploader

  include CarrierWave::Validations::ActiveModel

  validates_integrity_of  column if uploader_option(column.to_sym, :validate_integrity)
  validates_processing_of column if uploader_option(column.to_sym, :validate_processing)

  after_save :"store_#{column}!"
  before_save :"write_#{column}_identifier"
  after_destroy :"remove_#{column}!"
  if Gem::Version.new(CarrierWave::VERSION) >= Gem::Version.new("1.0.beta")
    before_update :"store_previous_changes_for_#{column}"
  else
    before_update :"store_previous_model_for_#{column}"
  end
  after_save :"remove_previously_stored_#{column}"

  class_eval <<-RUBY, __FILE__, __LINE__+1
    def #{column}=(new_file)
      column = _mounter(:#{column}).serialization_column

      # We're using _new_ and _old_ placeholder values to force Mongoid to
      # recognize changes in embedded documents. Before we assign these
      # values, we need to store the original file name in case we need to
      # delete it when document is saved.
      previous_uploader_value = read_uploader(column)
      @_previous_uploader_value_for_#{column} = previous_uploader_value

      # mongoid won't upload a new file if there was no file previously.
      write_uploader(column, '_old_') if self.persisted? && read_uploader(column).nil?

      send(:"\#{column}_will_change!")
      super
    end

    def remove_#{column}=(arg)
      if ['1', true].include?(arg)
        column = _mounter(:#{column}).serialization_column
        send(:"\#{column}_will_change!")
      end
      super
    end

    def remove_#{column}!
      super unless respond_to?(:paranoid?) && paranoid? && flagged_for_destroy?
    end

    # Overrides Mongoid's default dirty behavior to instead work more like
    # ActiveRecord's. Mongoid doesn't deem an attribute as changed unless
    # the new value is different than the original. Given that CarrierWave
    # caches files before save, it's necessary to know that there's a
    # pending change even though the attribute value itself might not
    # reflect that yet.
    def #{column}_changed?
      changed_attributes.has_key?("#{column}")
    end

    # The default Mongoid attribute_will_change! method is not enough
    # when we want to upload a new file in an existing embedded document.
    # The custom version of that method forces the callbacks to be
    # ran and so does the upload.
    def #{column}_will_change!
      changed_attributes["#{column}"] = '_new_'
    end

    # Since we had to use tricks with _old_ and _new_ values to properly
    # track changes in embedded documents, we need to overwrite this method
    # to remove the original file if it was replaced with a new one that
    # had a different name.
    if Gem::Version.new(CarrierWave::VERSION) >= Gem::Version.new("1.0.beta")
      def remove_previously_stored_#{column}
        before, after = @_previous_changes_for_#{column}
        # Don't delete if the files had the same name
        return if before.nil? && after.nil?
        # Proceed to remove the file, use the original name instead of '_new_'
        before = @_previous_uploader_value_for_#{column} || before
        _mounter(:#{column}).remove_previous([before], [after])
      end
    end

    # CarrierWave 1.1 references ::ActiveRecord constant directly which
    # will fail in projects without ActiveRecord. We need to overwrite this
    # method to avoid it.
    # See https://github.com/carrierwaveuploader/carrierwave/blob/07dc4d7bd7806ab4b963cf8acbad73d97cdfe74e/lib/carrierwave/mount.rb#L189
    def store_previous_changes_for_#{column}
      @_previous_changes_for_#{column} = changes[_mounter(:#{column}).serialization_column]
    end

    def find_previous_model_for_#{column}
      if self.embedded?
        if self.respond_to?(:__metadata) # Mongoid >= 4.0.0.beta1
          ancestors = [[ self.__metadata.key, self._parent ]].tap { |x| x.unshift([ x.first.last.__metadata.key, x.first.last._parent ]) while x.first.last.embedded? }
        else # Mongoid < 4.0.0.beta1
          ancestors = [[ self.metadata.key, self._parent ]].tap { |x| x.unshift([ x.first.last.metadata.key, x.first.last._parent ]) while x.first.last.embedded? }
        end
        first_parent = ancestors.first.last
        reloaded_parent = first_parent.class.unscoped.find(first_parent.to_key.first)
        association = ancestors.inject(reloaded_parent) { |parent,(key,ancestor)| (parent.is_a?(Array) ? parent.find(ancestor.to_key.first) : parent).send(key) }
        association.is_a?(Array) ? association.find(to_key.first) : association
      else
        self.class.unscoped.for_ids(to_key).first
      end
    end

    def serializable_hash(options=nil)
      hash = {}

      except = options && options[:except] && Array.wrap(options[:except]).map(&:to_s)
      only   = options && options[:only]   && Array.wrap(options[:only]).map(&:to_s)

      self.class.uploaders.each do |column, uploader|
        if (!only && !except) || (only && only.include?(column.to_s)) || (except && !except.include?(column.to_s))
          if Gem::Version.new(CarrierWave::VERSION) >= Gem::Version.new("1.0.beta")
            next if _mounter(column.to_sym).uploaders.blank?
            hash[column.to_s] = _mounter(column.to_sym).uploaders[0].serializable_hash
          else
            hash[column.to_s] = _mounter(column.to_sym).uploader.serializable_hash
          end
        end
      end
      super(options).merge(hash)
    end
  RUBY
end