Module: HasDynamicColumns::Model::ClassMethods

Defined in:

lib/has_dynamic_columns.rb

Instance Method Summary

• #has_dynamic_columns(*args) ⇒ Object

Instance Method Details

#has_dynamic_columns(*args) ⇒ Object

# File 'lib/has_dynamic_columns.rb', line 16

def has_dynamic_columns(*args)
	options = args.extract_options!
	configuration = {
		:as => "dynamic_columns",
		:field_scope => nil,
	}
       configuration.update(options) if options.is_a?(Hash)

	class_eval <<-EOV
		include ::HasDynamicColumns::Model::InstanceMethods

		has_many :activerecord_#{configuration[:as]},
					class_name: "HasDynamicColumns::DynamicColumn",
					as: :field_scope
		has_many :activerecord_#{configuration[:as]}_data,
					class_name: "HasDynamicColumns::DynamicColumnDatum",
					as: :owner

		# only add to attr_accessible
		# if the class has some mass_assignment_protection
		if defined?(accessible_attributes) and !accessible_attributes.blank?
			#attr_accessible :#{configuration[:column]}
		end

		validate :validate_dynamic_column_data

		public
			# Order by dynamic columns
			def self.dynamic_order(field_scope, key, direction = :asc)
				table = self.name.constantize.arel_table
				column_table = HasDynamicColumns::DynamicColumn.arel_table.alias("dynamic_order_"+key.to_s)
				column_datum_table = HasDynamicColumns::DynamicColumnDatum.arel_table.alias("dynamic_order_data_"+key.to_s)

				field_scope_type = field_scope.class.name.constantize.to_s
				dynamic_type = self.name.constantize.to_s
				field_scope_id = field_scope.id

				# Join on the column with the key
				column_table_join_on = column_table
										.create_on(
											column_table[:field_scope_type].eq(field_scope_type).and(
												column_table[:dynamic_type].eq(dynamic_type)
											).and(
												column_table[:field_scope_id].eq(field_scope_id)
											).and(
												column_table[:key].eq(key)
											)
										)

				column_table_join = table.create_join(column_table, column_table_join_on)
				query = joins(column_table_join)

				# Join on all the data with the provided key
				column_table_datum_join_on = column_datum_table
										.create_on(
											column_datum_table[:owner_id].eq(table[:id]).and(
												column_datum_table[:owner_type].eq(dynamic_type)
											).and(
												column_datum_table[:dynamic_column_id].eq(column_table[:id])
											)
										)

				column_table_datum_join = table.create_join(column_datum_table, column_table_datum_join_on)
				query = query.joins(column_table_datum_join)

				# Order
				query = query.order(column_datum_table[:value].send(direction))

				# Group required - we have many rows
				query = query.group(table[:id])

				query
			end

			# Find by dynamic columns
			def self.dynamic_where(*args)
				field_scope = args[0]
				options = args.extract_options!

				field_scope_type = field_scope.class.name.constantize.to_s
				dynamic_type = self.name.constantize.to_s
				field_scope_id = field_scope.id

				table = self.name.constantize.arel_table
				query = nil

				# Need to join on each of the keys we are performing where on
				options.each { |key, value|
					# Don't bother with empty values
					next if value.to_s.empty?

					column_table = HasDynamicColumns::DynamicColumn.arel_table.alias("dynamic_where_"+key.to_s)
					column_datum_table = HasDynamicColumns::DynamicColumnDatum.arel_table.alias("dynamic_where_data_"+key.to_s)

					# Join on the column with the key
					column_table_join_on = column_table
											.create_on(
												column_table[:field_scope_type].eq(field_scope_type).and(
													column_table[:dynamic_type].eq(dynamic_type)
												).and(
													column_table[:field_scope_id].eq(field_scope_id)
												).and(
													column_table[:key].eq(key)
												)
											)

					column_table_join = table.create_join(column_table, column_table_join_on)
					query = (query.nil?)? joins(column_table_join) : query.joins(column_table_join)

					# Join on all the data with the provided key
					column_table_datum_join_on = column_datum_table
											.create_on(
												column_datum_table[:owner_id].eq(table[:id]).and(
													column_datum_table[:owner_type].eq(dynamic_type)
												).and(
													column_datum_table[:dynamic_column_id].eq(column_table[:id])
												).and(
													column_datum_table[:value].matches("%"+value+"%")
												)
											)

					column_table_datum_join = table.create_join(column_datum_table, column_table_datum_join_on)
					query = query.joins(column_table_datum_join)
				}
				# Group required - we have many rows
				query = (query.nil?)? group(table[:id]) : query.group(table[:id])

				query
			end

			def as_json(*args)
				json = super(*args)
				options = args.extract_options!

				if !options[:root].nil?
					json[options[:root]][self.dynamic_columns_as] = self.send(self.dynamic_columns_as)
				else
					json[self.dynamic_columns_as] = self.send(self.dynamic_columns_as)
				end

				json
			end

			# Setter for dynamic field data
			def #{configuration[:as]}=data
				data.each_pair { |key, value|
					# We dont play well with this key
					if !self.storable_#{configuration[:as].to_s.singularize}_key?(key)
						raise NoMethodError
					end
					dynamic_column = self.#{configuration[:as].to_s.singularize}_key_to_dynamic_column(key)

					# We already have this key in database
					if existing = self.activerecord_#{configuration[:as]}_data.select { |i| i.dynamic_column == dynamic_column }.first
						existing.value = value
					else
						self.activerecord_#{configuration[:as]}_data.build(:dynamic_column => dynamic_column, :value => value)
					end
				}
			end

			def #{configuration[:as]}
				h = {}
				self.field_scope_#{configuration[:as]}.each { |i|
					h[i.key] = nil
				}
				self.activerecord_#{configuration[:as]}_data.each { |i|
					h[i.dynamic_column.key] = i.value unless !i.dynamic_column
				}
				h
			end

			def #{configuration[:as].to_s.singularize}_keys
				self.field_scope_#{configuration[:as]}.collect { |i| i.key }
			end

			def field_scope_#{configuration[:as]}
				self.field_scope.send("activerecord_"+self.field_scope.dynamic_columns_as).select { |i|
					# Only get things with no dynamic type defined or dynamic types defined as this class
					i.dynamic_type.to_s.empty? || i.dynamic_type.to_s == self.class.to_s
				}
			end

			def dynamic_columns_as
				"#{configuration[:as].to_s}"
			end

		protected
			# Whether this is storable
			def storable_#{configuration[:as].to_s.singularize}_key?(key)
				self.#{configuration[:as].to_s.singularize}_keys.include?(key.to_s)
			end

			# Figures out which dynamic_column has which key
			def #{configuration[:as].to_s.singularize}_key_to_dynamic_column(key)
				found = nil
				if record = self.send("field_scope_"+self.dynamic_columns_as).select { |i| i.key == key.to_s }.first
					found = record
				end
				found
			end

			def field_scope
				#{configuration[:field_scope]}
			end
	EOV
end