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Attributes
[RW] | abstract_class | Set this to Consider the following default behaviour:
However, when using
Note that in the above example, to disallow the creation of a plain |
[R] | base_class | Returns the class descending directly from If A extends If B < A and C < B and if A is an |
Instance Public methods
abstract_class?() Link
Returns whether this class is an abstract class or not.
base_class?() Link
Returns whether the class is a base class. See base_class
for more information.
descends_from_active_record?() Link
Returns true
if this does not need STI type condition. Returns false
if STI type condition needs to be applied.
inherited(subclass) Link
new(attributes = nil, &block) Link
Determines if one of the attributes passed in is the inheritance column, and if the inheritance column is attr accessible, it initializes an instance of the given subclass instead of the base class.
# File activerecord/lib/active_record/inheritance.rb, line 55 def new(attributes = nil, &block) if abstract_class? || self == Base raise NotImplementedError, "#{self} is an abstract class and cannot be instantiated." end if _has_attribute?(inheritance_column) subclass = subclass_from_attributes(attributes) if subclass.nil? && scope_attributes = current_scope&.scope_for_create subclass = subclass_from_attributes(scope_attributes) end if subclass.nil? && base_class? subclass = subclass_from_attributes(column_defaults) end end if subclass && subclass != self subclass.new(attributes, &block) else super end end
polymorphic_class_for(name) Link
Returns the class for the provided name
.
It is used to find the class correspondent to the value stored in the polymorphic type column.
polymorphic_name() Link
Returns the value to be stored in the polymorphic type column for Polymorphic Associations
.
primary_abstract_class() Link
Sets the application record class for Active Record
This is useful if your application uses a different class than ApplicationRecord for your primary abstract class. This class will share a database connection with Active Record. It is the class that connects to your primary database.
# File activerecord/lib/active_record/inheritance.rb, line 166 def primary_abstract_class if ActiveRecord.application_record_class && ActiveRecord.application_record_class.name != name raise ArgumentError, "The `primary_abstract_class` is already set to #{ActiveRecord.application_record_class.inspect}. There can only be one `primary_abstract_class` in an application." end self.abstract_class = true ActiveRecord.application_record_class = self end
sti_class_for(type_name) Link
Returns the class for the provided type_name
.
It is used to find the class correspondent to the value stored in the inheritance column.
# File activerecord/lib/active_record/inheritance.rb, line 183 def sti_class_for(type_name) if store_full_sti_class && store_full_class_name type_name.constantize else compute_type(type_name) end rescue NameError raise SubclassNotFound, "The single-table inheritance mechanism failed to locate the subclass: '#{type_name}'. " \ "This error is raised because the column '#{inheritance_column}' is reserved for storing the class in case of inheritance. " \ "Please rename this column if you didn't intend it to be used for storing the inheritance class " \ "or overwrite #{name}.inheritance_column to use another column for that information." end
sti_name() Link
Returns the value to be stored in the inheritance column for STI.
Instance Protected methods
compute_type(type_name) Link
Returns the class type of the record using the current module as a prefix. So descendants of MyApp::Business::Account would appear as MyApp::Business::AccountSubclass.
# File activerecord/lib/active_record/inheritance.rb, line 235 def compute_type(type_name) if type_name.start_with?("::") # If the type is prefixed with a scope operator then we assume that # the type_name is an absolute reference. type_name.constantize else type_candidate = @_type_candidates_cache[type_name] if type_candidate && type_constant = type_candidate.safe_constantize return type_constant end # Build a list of candidates to search for candidates = [] name.scan(/::|$/) { candidates.unshift "#{$`}::#{type_name}" } candidates << type_name candidates.each do |candidate| constant = candidate.safe_constantize if candidate == constant.to_s @_type_candidates_cache[type_name] = candidate return constant end end raise NameError.new("uninitialized constant #{candidates.first}", candidates.first) end end