Module: ActiveRecord::AttributeMethods::ClassMethods
- Defined in:
- lib/active_record/attribute_methods.rb
Instance Method Summary collapse
-
#attribute_method?(attribute) ⇒ Boolean
Returns
true
ifattribute
is an attribute method and table exists,false
otherwise. -
#attribute_names ⇒ Object
Returns an array of column names as strings if it’s not an abstract class and table exists.
-
#class_method_defined_within?(name, klass, superklass = klass.superclass) ⇒ Boolean
:nodoc.
-
#column_for_attribute(name) ⇒ Object
Returns the column object for the named attribute.
-
#dangerous_attribute_method?(name) ⇒ Boolean
A method name is ‘dangerous’ if it is already (re)defined by Active Record, but not by any ancestors.
-
#dangerous_class_method?(method_name) ⇒ Boolean
A class method is ‘dangerous’ if it is already (re)defined by Active Record, but not by any ancestors.
-
#define_attribute_methods ⇒ Object
Generates all the attribute related methods for columns in the database accessors, mutators and query methods.
-
#inherited(child_class) ⇒ Object
:nodoc:.
-
#initialize_generated_modules ⇒ Object
:nodoc:.
-
#instance_method_already_implemented?(method_name) ⇒ Boolean
Raises a
ActiveRecord::DangerousAttributeError
exception when an Active Record method is defined in the model, otherwisefalse
. -
#method_defined_within?(name, klass, superklass = klass.superclass) ⇒ Boolean
:nodoc:.
-
#undefine_attribute_methods ⇒ Object
:nodoc:.
Instance Method Details
#attribute_method?(attribute) ⇒ Boolean
Returns true
if attribute
is an attribute method and table exists, false
otherwise.
class Person < ActiveRecord::Base
end
Person.attribute_method?('name') # => true
Person.attribute_method?(:age=) # => true
Person.attribute_method?(:nothing) # => false
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# File 'lib/active_record/attribute_methods.rb', line 174 def attribute_method?(attribute) super || (table_exists? && column_names.include?(attribute.to_s.sub(/=$/, ''))) end |
#attribute_names ⇒ Object
Returns an array of column names as strings if it’s not an abstract class and table exists. Otherwise it returns an empty array.
class Person < ActiveRecord::Base
end
Person.attribute_names
# => ["id", "created_at", "updated_at", "name", "age"]
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# File 'lib/active_record/attribute_methods.rb', line 186 def attribute_names @attribute_names ||= if !abstract_class? && table_exists? column_names else [] end end |
#class_method_defined_within?(name, klass, superklass = klass.superclass) ⇒ Boolean
:nodoc
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# File 'lib/active_record/attribute_methods.rb', line 153 def class_method_defined_within?(name, klass, superklass = klass.superclass) # :nodoc if klass.respond_to?(name, true) if superklass.respond_to?(name, true) klass.method(name).owner != superklass.method(name).owner else true end else false end end |
#column_for_attribute(name) ⇒ Object
Returns the column object for the named attribute. Returns nil if the named attribute does not exist.
class Person < ActiveRecord::Base
end
person = Person.new
person.column_for_attribute(:name) # the result depends on the ConnectionAdapter
# => #<ActiveRecord::ConnectionAdapters::Column:0x007ff4ab083980 @name="name", @sql_type="varchar(255)", @null=true, ...>
person.column_for_attribute(:nothing)
# => nil
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# File 'lib/active_record/attribute_methods.rb', line 206 def column_for_attribute(name) column = columns_hash[name.to_s] if column.nil? ActiveSupport::Deprecation.warn(<<-MSG.squish) `#column_for_attribute` will return a null object for non-existent columns in Rails 5. Use `#has_attribute?` if you need to check for an attribute's existence. MSG end column end |
#dangerous_attribute_method?(name) ⇒ Boolean
A method name is ‘dangerous’ if it is already (re)defined by Active Record, but not by any ancestors. (So ‘puts’ is not dangerous but ‘save’ is.)
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# File 'lib/active_record/attribute_methods.rb', line 131 def dangerous_attribute_method?(name) # :nodoc: method_defined_within?(name, Base) end |
#dangerous_class_method?(method_name) ⇒ Boolean
A class method is ‘dangerous’ if it is already (re)defined by Active Record, but not by any ancestors. (So ‘puts’ is not dangerous but ‘new’ is.)
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# File 'lib/active_record/attribute_methods.rb', line 149 def dangerous_class_method?(method_name) BLACKLISTED_CLASS_METHODS.include?(method_name.to_s) || class_method_defined_within?(method_name, Base) end |
#define_attribute_methods ⇒ Object
Generates all the attribute related methods for columns in the database accessors, mutators and query methods.
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# File 'lib/active_record/attribute_methods.rb', line 79 def define_attribute_methods # :nodoc: return false if @attribute_methods_generated # Use a mutex; we don't want two threads simultaneously trying to define # attribute methods. generated_attribute_methods.synchronize do return false if @attribute_methods_generated superclass.define_attribute_methods unless self == base_class super(column_names) @attribute_methods_generated = true end true end |
#inherited(child_class) ⇒ Object
:nodoc:
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# File 'lib/active_record/attribute_methods.rb', line 64 def inherited(child_class) #:nodoc: child_class.initialize_generated_modules super end |
#initialize_generated_modules ⇒ Object
:nodoc:
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# File 'lib/active_record/attribute_methods.rb', line 69 def initialize_generated_modules # :nodoc: @generated_attribute_methods = GeneratedAttributeMethods.new { extend Mutex_m } @attribute_methods_generated = false include @generated_attribute_methods super end |
#instance_method_already_implemented?(method_name) ⇒ Boolean
Raises a ActiveRecord::DangerousAttributeError
exception when an Active Record method is defined in the model, otherwise false
.
class Person < ActiveRecord::Base
def save
'already defined by Active Record'
end
end
Person.instance_method_already_implemented?(:save)
# => ActiveRecord::DangerousAttributeError: save is defined by ActiveRecord
Person.instance_method_already_implemented?(:name)
# => false
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# File 'lib/active_record/attribute_methods.rb', line 113 def instance_method_already_implemented?(method_name) if dangerous_attribute_method?(method_name) raise DangerousAttributeError, "#{method_name} is defined by Active Record. Check to make sure that you don't have an attribute or method with the same name." end if superclass == Base super else # If ThisClass < ... < SomeSuperClass < ... < Base and SomeSuperClass # defines its own attribute method, then we don't want to overwrite that. defined = method_defined_within?(method_name, superclass, Base) && ! superclass.instance_method(method_name).owner.is_a?(GeneratedAttributeMethods) defined || super end end |
#method_defined_within?(name, klass, superklass = klass.superclass) ⇒ Boolean
:nodoc:
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# File 'lib/active_record/attribute_methods.rb', line 135 def method_defined_within?(name, klass, superklass = klass.superclass) # :nodoc: if klass.method_defined?(name) || klass.private_method_defined?(name) if superklass.method_defined?(name) || superklass.private_method_defined?(name) klass.instance_method(name).owner != superklass.instance_method(name).owner else true end else false end end |
#undefine_attribute_methods ⇒ Object
:nodoc:
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# File 'lib/active_record/attribute_methods.rb', line 92 def undefine_attribute_methods # :nodoc: generated_attribute_methods.synchronize do super if defined?(@attribute_methods_generated) && @attribute_methods_generated @attribute_methods_generated = false end end |