Configurability::

SettingInstaller class

Superclass	Object
Extended With	Loggability

Methods for declaring config methods and constants inside a ‘configurability` block.

Attributes

target R: The target object

Public Class Methods

new( target )

Create a new Generator that can be used to add configuration methods and constants to the specified target object.

# File lib/configurability/setting_installer.rb, line 17
def initialize( target )
        @target = target
end

Public Instance Methods

setting( name, **options, &block )

Declare a config setting with the specified name.

# File lib/configurability/setting_installer.rb, line 28
def setting( name, **options, &block )
        self.log.debug "  adding %s setting to %p" % [ name, self.target ]

        options[:alias] = Array( options[:alias] )
        self.add_setting_accessors( name, options, &block )
        self.add_default( name, options[:default] )
end

setting_default( name, new_default )

Declare a new default for the setting with the specified name.

# File lib/configurability/setting_installer.rb, line 38
def setting_default( name, new_default )
        self.add_default( name, new_default )
end

Protected Instance Methods

add_default( name, default_value )

Add a default for name to the CONFIG_DEFAULTS constant of the target, creating it if necessary.

# File lib/configurability/setting_installer.rb, line 141
def add_default( name, default_value )
        self.target.send( "#{name}=", default_value )
        if self.target.respond_to?( :const_defined? )
                defaults = if self.target.const_defined?( :CONFIG_DEFAULTS, false )
                                self.target.const_get( :CONFIG_DEFAULTS, false )
                        else
                                self.target.const_set( :CONFIG_DEFAULTS, {} )
                        end

                defaults.store( name, default_value )
        end
end

add_setting_accessors( name, options, &writer_hook )

Add accessors with the specified name to the target.

# File lib/configurability/setting_installer.rb, line 48
def add_setting_accessors( name, options, &writer_hook )
        self.check_for_duplicates( name, options )

        if options[:use_class_vars]
                self.target.class_variable_set( "@@#{name}", nil )
        else
                self.target.instance_variable_set( "@#{name}", nil )
        end

        reader = self.make_setting_reader( name, options )
        writer = self.make_setting_writer( name, options, &writer_hook )
        predicate = self.make_setting_predicate( name, options )
        names = [ name ] + options[:alias]

        names.each do |setting_name|
                self.target.define_singleton_method( "#{setting_name}", &reader )
                self.target.define_singleton_method( "#{setting_name}=", &writer )
                self.target.define_singleton_method( "#{setting_name}?", &predicate ) if
                        options[:predicate]
        end
end

check_for_duplicates( name, options )

Check that there are not already accessors for the setting with the given name and options.

# File lib/configurability/setting_installer.rb, line 73
def check_for_duplicates( name, options )
        names = [ name.to_sym ] + options[:alias]

        names.each do |method_name|
                raise ScriptError, "setting %p collides with method #%s" % [ name, method_name ] if
                        self.target.singleton_methods.include?( name )
                raise ScriptError, "setting %p collides with method #%s=" % [ name, method_name ] if
                        self.target.singleton_methods.include?( "#{method_name}=".to_sym )
                if options[:predicate]
                        raise ScriptError, "setting %p collides with method #%s?" % [ name, method_name ] if
                                self.target.singleton_methods.include?( "#{method_name}?".to_sym )
                end
        end
end

make_setting_predicate( name, options )

Create the body of the setting predicate method with the specified name and options.

# File lib/configurability/setting_installer.rb, line 124
def make_setting_predicate( name, options )
        if options[:use_class_vars]
                return lambda do
                        Loggability[ Configurability ].debug "Using class variables for %s of %p" %
                                [ name, self ]
                        self.class_variable_get("@@#{name}") ? true : false
                end
        else
                return lambda {
                        self.instance_variable_get("@#{name}") ? true : false
                }
        end
end

make_setting_reader( name, options )

Create the body of the setting reader method with the specified name and options.

# File lib/configurability/setting_installer.rb, line 90
def make_setting_reader( name, options )
        if options[:use_class_vars]
                return lambda do
                        Loggability[ Configurability ].debug "Using class variables for %s of %p" %
                                [ name, self ]
                        self.class_variable_get("@@#{name}")
                end
        else
                return lambda {
                        self.instance_variable_get("@#{name}")
                }
        end
end

make_setting_writer( name, options, &writer_hook )

Create the body of the setting writer method with the specified name and options.

# File lib/configurability/setting_installer.rb, line 106
def make_setting_writer( name, options, &writer_hook )
        if options[:use_class_vars]
                return lambda do |value|
                        Loggability[ Configurability ].debug "Using class variables for %s of %p" %
                                [ name, self ]
                        value = writer_hook[ value ] if writer_hook
                        self.class_variable_set( "@@#{name}", value )
                end
        else
                return lambda do |value|
                        value = writer_hook[ value ] if writer_hook
                        self.instance_variable_set( "@#{name}", value )
                end
        end
end