diff options
Diffstat (limited to 'activerecord/lib/active_record/dynamic_matchers.rb')
-rw-r--r-- | activerecord/lib/active_record/dynamic_matchers.rb | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/dynamic_matchers.rb b/activerecord/lib/active_record/dynamic_matchers.rb new file mode 100644 index 0000000000..e278e62ce7 --- /dev/null +++ b/activerecord/lib/active_record/dynamic_matchers.rb @@ -0,0 +1,130 @@ +module ActiveRecord + module DynamicMatchers #:nodoc: + # This code in this file seems to have a lot of indirection, but the indirection + # is there to provide extension points for the active_record_deprecated_finders + # gem. When we stop supporting active_record_deprecated_finders (from Rails 5), + # then we can remove the indirection. + + def respond_to?(name, include_private = false) + match = Method.match(self, name) + match && match.valid? || super + end + + private + + def method_missing(name, *arguments, &block) + match = Method.match(self, name) + + if match && match.valid? + match.define + send(name, *arguments, &block) + else + super + end + end + + class Method + @matchers = [] + + class << self + attr_reader :matchers + + def match(model, name) + klass = matchers.find { |k| name =~ k.pattern } + klass.new(model, name) if klass + end + + def pattern + /^#{prefix}_([_a-zA-Z]\w*)#{suffix}$/ + end + + def prefix + raise NotImplementedError + end + + def suffix + '' + end + end + + attr_reader :model, :name, :attribute_names + + def initialize(model, name) + @model = model + @name = name.to_s + @attribute_names = @name.match(self.class.pattern)[1].split('_and_') + end + + def valid? + attribute_names.all? { |name| model.columns_hash[name] || model.reflect_on_aggregation(name.to_sym) } + end + + def define + model.class_eval <<-CODE, __FILE__, __LINE__ + 1 + def self.#{name}(#{signature}) + #{body} + end + CODE + end + + def body + raise NotImplementedError + end + end + + module Finder + # Extended in active_record_deprecated_finders + def body + result + end + + # Extended in active_record_deprecated_finders + def result + "#{finder}(#{attributes_hash})" + end + + # Extended in active_record_deprecated_finders + def signature + attribute_names.join(', ') + end + + def attributes_hash + "{" + attribute_names.map { |name| ":#{name} => #{name}" }.join(',') + "}" + end + + def finder + raise NotImplementedError + end + end + + class FindBy < Method + Method.matchers << self + include Finder + + def self.prefix + "find_by" + end + + def finder + "find_by" + end + end + + class FindByBang < Method + Method.matchers << self + include Finder + + def self.prefix + "find_by" + end + + def self.suffix + "!" + end + + def finder + "find_by!" + end + end + end +end |