module Aquarium::Utils::OptionsUtils


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...

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:


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.


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.


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.



Public Class Methods

append_features(clazz) click to toggle source
Calls superclass method
    # File lib/aquarium/utils/options_utils.rb
227 def self.append_features clazz
228   super
229   ClassMethods.send :append_features, (class << clazz; self; end)
230 end
universal_options() click to toggle source
   # File lib/aquarium/utils/options_utils.rb
74 def self.universal_options
75   [:logger_stream, :logger, :severity, :noop]
76 end
universal_prepositions() click to toggle source
   # File lib/aquarium/utils/options_utils.rb
78 def self.universal_prepositions
79   [:for, :on, :in, :within]
80 end

Public Instance Methods

hashify(options) click to toggle source
    # File lib/aquarium/utils/options_utils.rb
125 def hashify options
126   return options if options.kind_of?(Hash)
127   new_options = {}
128   options = [options] unless options.kind_of?(Array)
129   options.each do |x|
130     if x.kind_of?(Hash)
131       new_options.merge!(x)
132     else
133       new_options[x] =[])
134     end
135   end
136   new_options
137 end
init_specification(options, canonical_options, additional_allowed_options = []) { || ... } click to toggle source

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
 95 def init_specification options, canonical_options, additional_allowed_options = []
 96   @canonical_options = canonical_options
 97   @additional_allowed_options ={|x| x.respond_to?(:intern) ? x.intern : x}
 98   @original_options = options.nil? ? {} : options.dup 
 99   @specification = {}
100   options ||= {} 
101   options_hash = hashify options
102   @canonical_options.keys.each do |key|
103     all_related_options = make_array(options_hash[key.intern]) || []
104     @canonical_options[key].inject(all_related_options) do |ary, o| 
105       ary << options_hash[o.intern] if options_hash[o.intern]
106       ary
107     end
108     @specification[key.intern] =
109   end
111   OptionsUtils::universal_options.each do |uopt| 
112     @specification[uopt] =[uopt])) unless options_hash[uopt].nil? 
113   end
114   @specification[:noop] ||=[false])
115   set_logger_if_stream_specified     
116   set_logger_severity_if_specified   
117   set_default_logger_if_not_specified 
119   ignorables = yield if block_given?
120   ignorables = [] if ignorables.nil? 
121   ignorables = [ignorables] unless ignorables.kind_of? Array
122   validate_options(options_hash.reject {|k,v| ignorables.include?(k)})
123 end
validate_options(options) click to toggle source
    # File lib/aquarium/utils/options_utils.rb
139 def validate_options options
140   unknowns = options.keys - all_allowed_option_symbols - OptionsUtils::universal_options
141   raise"Unknown options specified: #{unknowns.inspect}") if unknowns.size > 0
142 end