~michaelforrest/use-case-mapper/trunk

@_defined_class_methods ||= ancestors.first(ancestors.index(ActiveRecord::Base)).sum([]) { |m| m.public_instance_methods(false) | m.private_instance_methods(false) | m.protected_instance_methods(false) }.map(&:to_s).to_set

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@@_defined_activerecord_methods ||= (ActiveRecord::Base.public_instance_methods(false) | ActiveRecord::Base.private_instance_methods(false) | ActiveRecord::Base.protected_instance_methods(false)).map(&:to_s).to_set

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raise DangerousAttributeError, "#{method_name} is defined by ActiveRecord" if @@_defined_activerecord_methods.include?(method_name)

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@_defined_class_methods.include?(method_name)

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end

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alias :define_read_methods :define_attribute_methods

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# +cache_attributes+ allows you to declare which converted attribute values should

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# be cached. Usually caching only pays off for attributes with expensive conversion

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# methods, like time related columns (e.g. +created_at+, +updated_at+).

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def cache_attributes(*attribute_names)

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attribute_names.each {|attr| cached_attributes << attr.to_s}

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end

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# Returns the attributes which are cached. By default time related columns

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# with datatype <tt>:datetime, :timestamp, :time, :date</tt> are cached.

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def cached_attributes

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@cached_attributes ||=

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columns.select{|c| attribute_types_cached_by_default.include?(c.type)}.map(&:name).to_set

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end

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# Returns +true+ if the provided attribute is being cached.

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def cache_attribute?(attr_name)

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cached_attributes.include?(attr_name)

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end

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private

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# Suffixes a, ?, c become regexp /(a|\?|c)$/

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def rebuild_attribute_method_regexp

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suffixes = attribute_method_suffixes.map { |s| Regexp.escape(s) }

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@@attribute_method_regexp = /(#{suffixes.join('|')})$/.freeze

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end

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# Default to =, ?, _before_type_cast

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def attribute_method_suffixes

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@@attribute_method_suffixes ||= []

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end

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def create_time_zone_conversion_attribute?(name, column)

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time_zone_aware_attributes && !skip_time_zone_conversion_for_attributes.include?(name.to_sym) && [:datetime, :timestamp].include?(column.type)

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end

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# Define an attribute reader method. Cope with nil column.

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def define_read_method(symbol, attr_name, column)

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cast_code = column.type_cast_code('v') if column

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access_code = cast_code ? "(v=@attributes['#{attr_name}']) && #{cast_code}" : "@attributes['#{attr_name}']"

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unless attr_name.to_s == self.primary_key.to_s

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access_code = access_code.insert(0, "missing_attribute('#{attr_name}', caller) unless @attributes.has_key?('#{attr_name}'); ")

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end

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if cache_attribute?(attr_name)

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access_code = "@attributes_cache['#{attr_name}'] ||= (#{access_code})"

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end

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evaluate_attribute_method attr_name, "def #{symbol}; #{access_code}; end"

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end

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# Define read method for serialized attribute.

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def define_read_method_for_serialized_attribute(attr_name)

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evaluate_attribute_method attr_name, "def #{attr_name}; unserialize_attribute('#{attr_name}'); end"

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end

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# Defined for all +datetime+ and +timestamp+ attributes when +time_zone_aware_attributes+ are enabled.

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# This enhanced read method automatically converts the UTC time stored in the database to the time zone stored in Time.zone.

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def define_read_method_for_time_zone_conversion(attr_name)

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method_body = <<-EOV

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def #{attr_name}(reload = false)

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cached = @attributes_cache['#{attr_name}']

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return cached if cached && !reload

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time = read_attribute('#{attr_name}')

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@attributes_cache['#{attr_name}'] = time.acts_like?(:time) ? time.in_time_zone : time

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end

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EOV

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evaluate_attribute_method attr_name, method_body

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end

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# Defines a predicate method <tt>attr_name?</tt>.

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def define_question_method(attr_name)

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evaluate_attribute_method attr_name, "def #{attr_name}?; query_attribute('#{attr_name}'); end", "#{attr_name}?"

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end

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def define_write_method(attr_name)

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evaluate_attribute_method attr_name, "def #{attr_name}=(new_value);write_attribute('#{attr_name}', new_value);end", "#{attr_name}="

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end

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# Defined for all +datetime+ and +timestamp+ attributes when +time_zone_aware_attributes+ are enabled.

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# This enhanced write method will automatically convert the time passed to it to the zone stored in Time.zone.

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def define_write_method_for_time_zone_conversion(attr_name)

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method_body = <<-EOV

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def #{attr_name}=(time)

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unless time.acts_like?(:time)

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time = time.is_a?(String) ? Time.zone.parse(time) : time.to_time rescue time

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end

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time = time.in_time_zone rescue nil if time

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write_attribute(:#{attr_name}, time)

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end

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EOV

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evaluate_attribute_method attr_name, method_body, "#{attr_name}="

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end

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# Evaluate the definition for an attribute related method

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def evaluate_attribute_method(attr_name, method_definition, method_name=attr_name)

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unless method_name.to_s == primary_key.to_s

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generated_methods << method_name

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end

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begin

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class_eval(method_definition, __FILE__, __LINE__)

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rescue SyntaxError => err

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generated_methods.delete(attr_name)

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if logger

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logger.warn "Exception occurred during reader method compilation."

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logger.warn "Maybe #{attr_name} is not a valid Ruby identifier?"

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logger.warn err.message

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end

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end

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end

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end # ClassMethods

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# Allows access to the object attributes, which are held in the <tt>@attributes</tt> hash, as though they

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# were first-class methods. So a Person class with a name attribute can use Person#name and

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# Person#name= and never directly use the attributes hash -- except for multiple assigns with

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# ActiveRecord#attributes=. A Milestone class can also ask Milestone#completed? to test that

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# the completed attribute is not +nil+ or 0.

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# It's also possible to instantiate related objects, so a Client class belonging to the clients

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# table with a +master_id+ foreign key can instantiate master through Client#master.

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def method_missing(method_id, *args, &block)

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method_name = method_id.to_s

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if self.class.private_method_defined?(method_name)

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raise NoMethodError.new("Attempt to call private method", method_name, args)

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end

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# If we haven't generated any methods yet, generate them, then

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# see if we've created the method we're looking for.

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if !self.class.generated_methods?

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self.class.define_attribute_methods

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if self.class.generated_methods.include?(method_name)

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return self.send(method_id, *args, &block)

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end

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end

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if self.class.primary_key.to_s == method_name

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elsif md = self.class.match_attribute_method?(method_name)

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attribute_name, method_type = md.pre_match, md.to_s

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if @attributes.include?(attribute_name)

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__send__("attribute#{method_type}", attribute_name, *args, &block)

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else

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super

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end

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elsif @attributes.include?(method_name)

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read_attribute(method_name)

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else

260

super

261

end

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end

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# Returns the value of the attribute identified by <tt>attr_name</tt> after it has been typecast (for example,

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# "2004-12-12" in a data column is cast to a date object, like Date.new(2004, 12, 12)).

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def read_attribute(attr_name)

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attr_name = attr_name.to_s

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if !(value = @attributes[attr_name]).nil?

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if column = column_for_attribute(attr_name)

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if unserializable_attribute?(attr_name, column)

271

unserialize_attribute(attr_name)

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else

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column.type_cast(value)

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end

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else

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value

277

end

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else

279

nil

280

end

281

end

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def read_attribute_before_type_cast(attr_name)

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@attributes[attr_name]

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end

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# Returns true if the attribute is of a text column and marked for serialization.

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def unserializable_attribute?(attr_name, column)

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column.text? && self.class.serialized_attributes[attr_name]

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end

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# Returns the unserialized object of the attribute.

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def unserialize_attribute(attr_name)

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unserialized_object = object_from_yaml(@attributes[attr_name])

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if unserialized_object.is_a?(self.class.serialized_attributes[attr_name]) || unserialized_object.nil?

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@attributes.frozen? ? unserialized_object : @attributes[attr_name] = unserialized_object

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else

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raise SerializationTypeMismatch,

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"#{attr_name} was supposed to be a #{self.class.serialized_attributes[attr_name]}, but was a #{unserialized_object.class.to_s}"

301

end

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end

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# Updates the attribute identified by <tt>attr_name</tt> with the specified +value+. Empty strings for fixnum and float

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# columns are turned into +nil+.

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def write_attribute(attr_name, value)

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attr_name = attr_name.to_s

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@attributes_cache.delete(attr_name)

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if (column = column_for_attribute(attr_name)) && column.number?

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@attributes[attr_name] = convert_number_column_value(value)

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else

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@attributes[attr_name] = value

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end

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end

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def query_attribute(attr_name)

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unless value = read_attribute(attr_name)

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false

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else

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column = self.class.columns_hash[attr_name]

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if column.nil?

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if Numeric === value || value !~ /[^0-9]/

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!value.to_i.zero?

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else

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return false if ActiveRecord::ConnectionAdapters::Column::FALSE_VALUES.include?(value)

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!value.blank?

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end

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elsif column.number?

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!value.zero?

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else

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!value.blank?

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end

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end

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end

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# A Person object with a name attribute can ask <tt>person.respond_to?(:name)</tt>,

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# <tt>person.respond_to?(:name=)</tt>, and <tt>person.respond_to?(:name?)</tt>

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# which will all return +true+.

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alias :respond_to_without_attributes? :respond_to?

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def respond_to?(method, include_private_methods = false)

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method_name = method.to_s

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if super

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return true

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elsif !include_private_methods && super(method, true)

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# If we're here than we haven't found among non-private methods

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# but found among all methods. Which means that given method is private.

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return false

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elsif !self.class.generated_methods?

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self.class.define_attribute_methods

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if self.class.generated_methods.include?(method_name)

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return true

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end

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end

356

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if @attributes.nil?

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return super

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elsif @attributes.include?(method_name)

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return true

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elsif md = self.class.match_attribute_method?(method_name)

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return true if @attributes.include?(md.pre_match)

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end

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super

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end

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private

368

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def missing_attribute(attr_name, stack)

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raise ActiveRecord::MissingAttributeError, "missing attribute: #{attr_name}", stack

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end

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# Handle *? for method_missing.

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def attribute?(attribute_name)

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query_attribute(attribute_name)

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end

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# Handle *= for method_missing.

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def attribute=(attribute_name, value)

380

write_attribute(attribute_name, value)

381

end

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# Handle *_before_type_cast for method_missing.

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def attribute_before_type_cast(attribute_name)

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read_attribute_before_type_cast(attribute_name)

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end

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end

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end

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