Support parsing and processing of key-value pairs of options, where the
values are always converted to Sets. Types including this module should
have their initialize
methods call this module’s init_specification
to do the options processing. See its documentation for more details.
Several class methods are included for defining convenience
instance methods. For example, for options :foo
and
:bar
, calling:
canonical_options_given_methods :foo, :bar
will define several methods for each option specified, e.g.,:
foo_given # => returns the value of @specification[:foo] foo_given? # => returns true "foo_given" is not nil or empty. bar_given # etc... bar_given?
If you would like corresponding reader and writer methods, pass a list of the keys for which you want these methods defined to one of the following methods:
canonical_option_reader :foo, :bar # analogous to attr_reader canonical_option_writer :foo, :bar # analogous to attr_writer canonical_option_accessor :foo, :bar # analogous to attr_accessor
For all of these methods, you can also pass CANONICAL_OPTIONS
(discussed below) to define methods for all of the “canonical” options,
e.g.,
canonical_option_accessor CANONICAL_OPTIONS
These methods are not defined by default to prevent accidentally overriding other methods that you might have defined with the same names. Also, note that the writer methods will convert the inputs to sets, following the conventions for the options and the readers will return the sets. If you want different handling, you’ll have to provide custom implementations.
Note that special-case accessor methods are already defined for the
:noop
and :logger
options (discussed below) where
the writers expect single values, not sets, and the readers return the
single values. (Yea, it’s a bit inconsistent…)
Finally, these canonical_option_*
methods should only be
called with the keys for the
CANONICAL_OPTIONS
. The keys are considered the “canonical
options”, while the values for the keys are synonyms that can be used
instead.
This module also defines several universal options that will be available to all types that include this module:
:logger
A Ruby standard library Logger used for any messages. A default system-wide
logger is used otherwise. The corresponding logger
and
logger=
accessors are defined.
:logger_stream
An an alternative to defining the logger, you can define just the output
stream where log output will be written. If this option is specified, a new
logger will be created for the instance with this output stream. There are
no corresponding accessors; use the appropriate methods on the
logger
object instead.
:severity
The logging severity level, one of the Logger::Severity values or a
corresponding integer value. If this option is specified, a new logger will
be created for the instance with this output stream. There are no
corresponding accessors; use the corresponding methods on the
logger
object instead.
:noop => options_hash[:noop] || false
If true, don’t do “anything”, the interpretation of which will vary with the type receiving the option. For example, a type might go through some initialization, such as parsng its options, but do nothing after that. Primarily useful for debugging and testing.
The value can be accessed through the noop
and
noop=
accessors.
# File lib/aquarium/utils/options_utils.rb, line 227 def self.append_features clazz super ClassMethods.send :append_features, (class << clazz; self; end) end
# File lib/aquarium/utils/options_utils.rb, line 74 def self.universal_options [:logger_stream, :logger, :severity, :noop] end
# File lib/aquarium/utils/options_utils.rb, line 78 def self.universal_prepositions [:for, :on, :in, :within] end
# File lib/aquarium/utils/options_utils.rb, line 125 def hashify options return options if options.kind_of?(Hash) new_options = {} options = [options] unless options.kind_of?(Array) options.each do |x| if x.kind_of?(Hash) new_options.merge!(x) else new_options[x] = Set.new([]) end end new_options end
Class initialize methods call this method to process the input options. Pass an optional block to the method that takes no parameters if you want to do additional processing of the options before #init_specification validates the options. The block will have access to the @specification hash built up by #init_specification and to a new attribute @original_options, which will be a copy of the original options passed to #init_specification (it will be either a hash or an array). Finally, if the block returns a value or an array of values, they will be treated as keys to ignore in the options when they are validated. This is a way of dynamically treating an option as valid that can’t be known in advance. (See Aspect and Pointcut for examples of this feature in use.)
# File lib/aquarium/utils/options_utils.rb, line 95 def init_specification options, canonical_options, additional_allowed_options = [] @canonical_options = canonical_options @additional_allowed_options = additional_allowed_options.map{|x| x.respond_to?(:intern) ? x.intern : x} @original_options = options.nil? ? {} : options.dup @specification = {} options ||= {} options_hash = hashify options @canonical_options.keys.each do |key| all_related_options = make_array(options_hash[key.intern]) || [] @canonical_options[key].inject(all_related_options) do |ary, o| ary << options_hash[o.intern] if options_hash[o.intern] ary end @specification[key.intern] = Set.new(all_related_options.flatten) end OptionsUtils::universal_options.each do |uopt| @specification[uopt] = Set.new(make_array(options_hash[uopt])) unless options_hash[uopt].nil? end @specification[:noop] ||= Set.new([false]) set_logger_if_stream_specified set_logger_severity_if_specified set_default_logger_if_not_specified ignorables = yield if block_given? ignorables = [] if ignorables.nil? ignorables = [ignorables] unless ignorables.kind_of? Array validate_options(options_hash.reject {|k,v| ignorables.include?(k)}) end
# File lib/aquarium/utils/options_utils.rb, line 139 def validate_options options unknowns = options.keys - all_allowed_option_symbols - OptionsUtils::universal_options raise Aquarium::Utils::InvalidOptions.new("Unknown options specified: #{unknowns.inspect}") if unknowns.size > 0 end