Ravn::Actor::

Statefulness module

A mixin that adds persistent state managed by the StateManager to a Ravn::Actor.

Constants

DEFAULT_VARIABLE_OPTIONS: The default optiosn for variables

Public Class Methods

extended( object )

Extension callback – install instance methods in the extended object.

# File lib/ravn/actor/statefulness.rb, line 17
def self::extended( object )
        super
        object.instance_variable_set( :@stateful_variables, {} )
        object.singleton_class.attr_reader( :stateful_variables )
        object.prepend( InstanceMethods )
end

Public Instance Methods

inherited( subclass )

Inheritance hook – give subclasses their own stateful variables.

# File lib/ravn/actor/statefulness.rb, line 26
def inherited( subclass )
        super

        subclass.instance_variable_set( :@stateful_variables, {} )
        subclass.define_singleton_method( :stateful_variables ) do
                inherited_vars = superclass.stateful_variables
                self.log.warn "Returning stateful_variables merged into %p" % [ inherited_vars ]
                return inherited_vars.merge( @stateful_variables )
        end
end

make_stateful_variable_predicate( name, **options )

Return a lambda for the method body of a instance predicate for the variable named name. The options control specialized behavior of the method.

# File lib/ravn/actor/statefulness.rb, line 75
def make_stateful_variable_predicate( name, **options )
        default = Ravn::DataUtilities.deep_copy( options[:default] )
        return lambda do
                self.state_proxy.fetch( name, default ) ? true : false
        end
end

make_stateful_variable_reader( name, **options )

Return a lambda for the method body of a instance reader for the variable named name. The options control specialized behavior of the method.

# File lib/ravn/actor/statefulness.rb, line 65
def make_stateful_variable_reader( name, **options )
        default = Ravn::DataUtilities.deep_copy( options[:default] )
        return lambda do
                self.state_proxy.fetch( name, default )
        end
end

make_stateful_variable_writer( name, **options )

Return a lambda for the method body of a instance writer for the variable named name. The options control specialized behavior of the method.

# File lib/ravn/actor/statefulness.rb, line 85
def make_stateful_variable_writer( name, **options )
        return lambda do |new_value|
                self.state_proxy.store( name, new_value )
        end
end

stateful_variable( name, **options )

Declare a stateful variable that will be associated with the Bolt.

# File lib/ravn/actor/statefulness.rb, line 39
def stateful_variable( name, **options )
        self.log.debug "Adding a %p stateful variable: %p" % [ name, options ]
        options = DEFAULT_VARIABLE_OPTIONS.merge( options )

        if self.instance_methods.include?( name.to_sym )
                raise ScriptError,
                        "%p stateful variable collides with existing instance method." % [ name ]
        end

        @stateful_variables[ name ] = options

        if options[:predicate]
                predicate = self.make_stateful_variable_predicate( name, **options )
                define_method( "#{name}?", &predicate )
        else
                reader = self.make_stateful_variable_reader( name, **options )
                define_method( name, &reader )
        end

        writer = self.make_stateful_variable_writer( name, **options )
        define_method( "#{name}=", &writer )
end

stateful_variable_defaults()

Return a hash of declared variables and their default values.

# File lib/ravn/actor/statefulness.rb, line 93
def stateful_variable_defaults
        return self.stateful_variables.each_with_object( {} ) do |(var, opts), acc|
                default = opts[ :default ]
                acc[ var ] = default
        end
end