Method: Sequel::Postgres::PGRow::DatabaseMethods#register_row_type

Defined in:

lib/sequel/extensions/pg_row.rb

#register_row_type(db_type, opts = OPTS) ⇒ Object

Register a new row type for the Database instance. db_type should be the type symbol. This parses the PostgreSQL system tables to get information the composite type, and by default has the type return instances of a subclass of HashRow.

The following options are supported:

:converter

Use a custom converter for the parser.

:typecaster

Use a custom typecaster for the parser.

# File 'lib/sequel/extensions/pg_row.rb', line 434

def register_row_type(db_type, opts=OPTS)
  procs = @conversion_procs
  rel_oid = nil
  array_oid = nil
  parser_opts = {}

  # Try to handle schema-qualified types.
  type_schema, type_name = schema_and_table(db_type)
  schema_type_string = type_name.to_s

  # Get basic oid information for the composite type.
  ds = from(:pg_type).
    select{[pg_type[:oid], :typrelid, :typarray]}.
    where([[:typtype, 'c'], [:typname, type_name.to_s]])
  if type_schema
    ds = ds.join(:pg_namespace, [[:oid, :typnamespace], [:nspname, type_schema.to_s]])
    schema_type_symbol = :"pg_row_#{type_schema}__#{type_name}" 
  else
    schema_type_symbol = :"pg_row_#{type_name}"
  end
  unless row = ds.first
    raise Error, "row type #{db_type.inspect} not found in database"
  end
  # Manually cast to integer using to_i, because adapter may not cast oid type
  # correctly (e.g. swift)
  parser_opts[:oid], rel_oid, array_oid = row.values_at(:oid, :typrelid, :typarray).map(&:to_i)

  # Get column names and oids for each of the members of the composite type.
  res = from(:pg_attribute).
    join(:pg_type, :oid=>:atttypid).
    where(:attrelid=>rel_oid).
    where{attnum > 0}.
    exclude(:attisdropped).
    order(:attnum).
    select_map{[:attname, Sequel.case({0=>:atttypid}, pg_type[:typbasetype], pg_type[:typbasetype]).as(:atttypid)]}
  if res.empty?
    raise Error, "no columns for row type #{db_type.inspect} in database"
  end
  parser_opts[:columns] = res.map{|r| r[0].to_sym}
  parser_opts[:column_oids] = res.map{|r| r[1].to_i}

  # Using the conversion_procs, lookup converters for each member of the composite type
  parser_opts[:column_converters] = parser_opts[:column_oids].map do |oid|
    procs[oid]
  end

  # Setup the converter and typecaster
  parser_opts[:converter] = opts.fetch(:converter){HashRow.subclass(db_type, parser_opts[:columns])}
  parser_opts[:typecaster] = opts.fetch(:typecaster, parser_opts[:converter])

  parser = Parser.new(parser_opts)
  add_conversion_proc(parser.oid, parser)

  if respond_to?(:register_array_type) && array_oid && array_oid > 0
    array_type_name = if type_schema
      "#{type_schema}.#{type_name}"
    else
      type_name
    end
    register_array_type(array_type_name, :oid=>array_oid, :converter=>parser, :scalar_typecast=>schema_type_symbol)
  end

  @row_types[literal(db_type)] = opts.merge(:parser=>parser, :type=>db_type)
  @row_schema_types[schema_type_string] = schema_type_symbol 
  @schema_type_classes[schema_type_symbol] = ROW_TYPE_CLASSES
  @row_type_method_module.class_eval do
    meth = :"typecast_value_#{schema_type_symbol}"
    define_method(meth) do |v|
      row_type(db_type, v)
    end
    private meth
    alias_method(meth, meth)
  end

  nil
end