module Neo4j::TypeConverters

Responsible for converting values from and to Java Neo4j and Lucene. You can implement your own converter by implementing the method convert? to_java and to_ruby in this module.

There are currently three default converters that are triggered when a Time, Date or a DateTime is read or written if there is a type declared for the property.

Example

Example of writing your own marshalling converter:

class Foo
   include Neo4j::NodeMixin
   property :thing, :type => MyType
end

module Neo4j::TypeConverters
  class MyTypeConverter
    class << self
      def convert?(type)
        type == MyType
      end

      def to_java(val)
        "silly:#{val}"
      end

      def to_ruby(val)
        val.sub(/silly:/, '')
      end
    end
  end
end

Public Class Methods

convert(value, attribute = nil, klass = nil, enforce_type = true) click to toggle source

Converts the given value to a Java type by using the registered converters. It just looks at the class of the given value unless an attribute name is given. It will convert it if there is a converter registered (in Neo4j::Config) for this value.

# File lib/neo4j/type_converters/type_converters.rb, line 246
def convert(value, attribute = nil, klass = nil, enforce_type = true)
  converter(attribute_type(value, attribute, klass), enforce_type).to_java(value)
end

converter(type = nil, enforce_type = true) click to toggle source

Always returns a converter that handles ::to_ruby or ::to_java if enforce_type is set to false then it will raise in case of unknown type otherwise it will return the DevaultConverter.

# File lib/neo4j/type_converters/type_converters.rb, line 229
def converter(type = nil, enforce_type = true)
  return DefaultConverter unless type
  @converters ||= begin
    Neo4j::TypeConverters.constants.find_all do |c|
      Neo4j::TypeConverters.const_get(c).respond_to?(:convert?)
    end.map do  |c|
      Neo4j::TypeConverters.const_get(c)
    end
  end
  found = @converters.find {|c| c.convert?(type) }
  raise "The type #{type.inspect} is unknown. Use one of #{@converters.map{|c| c.name.demodulize.sub('Converter','') }.join(", ")} or create a custom type converter." if !found && enforce_type
  found or DefaultConverter
end

converters=(converters) click to toggle source

Mostly for testing purpose, You can use this method in order to add a converter while the neo4j has already started.

# File lib/neo4j/type_converters/type_converters.rb, line 222
def converters=(converters)
  @converters = converters
end

to_java(clazz, key, value) click to toggle source

Converts the given property (key, value) to Java if there is a type converter for given type. The type must also be declared using Neo4j::NodeMixin#property property_name, :type => clazz If no Converter is defined for this value then it simply returns the given value.

# File lib/neo4j/type_converters/type_converters.rb, line 253
def to_java(clazz, key, value)
  type = clazz._decl_props[key.to_sym] && clazz._decl_props[key.to_sym][:type]
  converter(type).to_java(value)
end

to_ruby(clazz, key, value) click to toggle source

Converts the given property (key, value) to Ruby if there is a type converter for given type. If no Converter is defined for this value then it simply returns the given value.

# File lib/neo4j/type_converters/type_converters.rb, line 260
def to_ruby(clazz, key, value)
  type = clazz._decl_props[key.to_sym] && clazz._decl_props[key.to_sym][:type]
  converter(type).to_ruby(value)
end