instance method
acts_like?
Ruby on Rails 7.0.10
Since v2.2.3Signature
acts_like?(duck)Provides a way to check whether some class acts like some other class based on the existence of an appropriately-named marker method.
A class that provides the same interface as SomeClass may define a marker method named acts_like_some_class? to signal its compatibility to callers of acts_like?(:some_class).
For example, Active Support extends Date to define an acts_like_date? method, and extends Time to define acts_like_time?. As a result, developers can call x.acts_like?(:time) and x.acts_like?(:date) to test duck-type compatibility, and classes that are able to act like Time can also define an acts_like_time? method to interoperate.
Note that the marker method is only expected to exist. It isn’t called, so its body or return value are irrelevant.
Example: A class that provides the same interface as String
This class may define:
class Stringish def acts_like_string? end end
Then client code can query for duck-type-safeness this way:
Stringish.new.acts_like?(:string) # => true
Parameters
-
duckreq
Source
# File activesupport/lib/active_support/core_ext/object/acts_like.rb, line 33
def acts_like?(duck)
case duck
when :time
respond_to? :acts_like_time?
when :date
respond_to? :acts_like_date?
when :string
respond_to? :acts_like_string?
else
respond_to? :"acts_like_#{duck}?"
end
end
Defined in activesupport/lib/active_support/core_ext/object/acts_like.rb line 33
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Defined in Object