Module: DatastaxRails::Inheritance::ClassMethods
- Defined in:
- lib/datastax_rails/inheritance.rb
Overview
:nodoc:
Instance Attribute Summary collapse
-
#abstract_class ⇒ Object
Set this to true if this is an abstract class (see
abstract_class?
).
Instance Method Summary collapse
-
#abstract_class? ⇒ Boolean
Returns whether this class is an abstract class or not.
-
#base_class ⇒ Object
Returns the class descending directly from DatastaxRails::Base, or an abstract class, if any, in the inheritance hierarchy.
-
#new(*args, &block) ⇒ Object
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.
Instance Attribute Details
#abstract_class ⇒ Object
Set this to true if this is an abstract class (see abstract_class?
). If you are using inheritance with DatastaxRails and don’t want child classes to utilize the implied STI table name of the parent class, this will need to be true. For example, given the following:
class SuperClass < DatastaxRails::Base
self.abstract_class = true
end
class Child < SuperClass
self.column_family = 'the_table_i_really_want'
end
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# File 'lib/datastax_rails/inheritance.rb', line 56 def abstract_class @abstract_class end |
Instance Method Details
#abstract_class? ⇒ Boolean
Returns whether this class is an abstract class or not.
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# File 'lib/datastax_rails/inheritance.rb', line 59 def abstract_class? defined?(@abstract_class) && @abstract_class == true end |
#base_class ⇒ Object
Returns the class descending directly from DatastaxRails::Base, or an abstract class, if any, in the inheritance hierarchy.
If A extends AR::Base, A.base_class will return A. If B descends from A through some arbitrarily deep hierarchy, B.base_class will return A.
If B < A and C < B and if A is an abstract_class then both B.base_class and C.base_class would return B as the answer since A is an abstract_class.
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# File 'lib/datastax_rails/inheritance.rb', line 33 def base_class unless self < Base fail DatastaxRailsError, "#{name} doesn't belong in a hierarchy descending from DatastaxRails" end if superclass == Base || superclass.abstract_class? self else superclass.base_class end end |
#new(*args, &block) ⇒ Object
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.
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# File 'lib/datastax_rails/inheritance.rb', line 12 def new(*args, &block) if abstract_class? || self == Base fail NotImplementedError, "#{self} is an abstract class and can not be instantiated." end # if (attrs = args.first).is_a?(Hash) # if subclass = subclass_from_attrs(attrs) # return subclass.new(*args, &block) # end # end # Delegate to the original .new super end |