A Clash is a “Chainable Lazy Hash”. Inspired by libraries such as Arel, a Clash allows you to chain together method arguments to build a hash, something that's especially useful if you're doing something like constructing a complex options hash. Here's a basic example:
c = Hashie::Clash.new.conditions(:foo => 'bar').order(:created_at) c # => {:conditions => {:foo => 'bar'}, :order => :created_at}
Clash provides another way to create sub-hashes by using bang notation. You can dive into a sub-hash by providing a key with a bang and dive back out again with the _end! method. Example:
c = Hashie::Clash.new.conditions!.foo('bar').baz(123)._end!.order(:created_at) c # => { conditions: { foo: 'bar', baz: 123 }, order: :created_at}
Because the primary functionality of Clash is to build options objects, all keys are converted to symbols since many libraries expect symbols explicitly for keys.
# File lib/hashie/clash.rb, line 87 def respond_to_missing?(method_name, _include_private = false) method_name = method_name.to_s if method_name.end_with?('!') key = method_name[0...-1].to_sym [NilClass, Clash, Hash].include?(self[key].class) else true end end