Module: Sequel::Plugins::SingleTableInheritance::ClassMethods

Attributes

sti_dataset	[R]	The base dataset for STI, to which filters are added to get only the models for the specific STI subclass.
sti_key	[R]	The column name holding the STI key for this model
sti_key_array	[R]	Array holding keys for all subclasses of this class, used for the dataset filter in subclasses. Nil in the main class.
sti_key_chooser	[R]	A proc which returns the value to use for new instances. This defaults to a lookup in the key map.
sti_key_map	[R]	A hash/proc with class keys and column value values, mapping the class to a particular value given to the sti_key column. Used to set the column value when creating objects, and for the filter when retrieving objects in subclasses.
sti_model_map	[R]	A hash/proc with column value keys and class values, mapping the value of the sti_key column to the appropriate class to use.

Public Instance methods

freeze()

Freeze STI information when freezing model class. Note that because of how STI works, you should not freeze an STI subclass until after all subclasses of it have been created.

[Source]

     # File lib/sequel/plugins/single_table_inheritance.rb, line 158
158:         def freeze
159:           @sti_key_array.freeze if @sti_key_array
160:           @sti_key_map.freeze if @sti_key_map.is_a?(Hash)
161:           @sti_model_map.freeze if @sti_model_map.is_a?(Hash)
162: 
163:           super
164:         end

inherited(subclass)

Copy the necessary attributes to the subclasses, and filter the subclass‘s dataset based on the sti_kep_map entry for the class.

[Source]

     # File lib/sequel/plugins/single_table_inheritance.rb, line 168
168:         def inherited(subclass)
169:           super
170:           key = Array(sti_key_map[subclass]).dup
171:           sti_subclass_added(key)
172:           rp = dataset.row_proc
173:           subclass.set_dataset(sti_subclass_dataset(key), :inherited=>true)
174:           subclass.instance_exec do
175:             @dataset = @dataset.with_row_proc(rp)
176:             @sti_key_array = key
177:             self.simple_table = nil
178:           end
179:         end

sti_class_from_sti_key(key)

Return the sti class based on one of the keys from sti_model_map.

[Source]

     # File lib/sequel/plugins/single_table_inheritance.rb, line 188
188:         def sti_class_from_sti_key(key)
189:           sti_class(sti_model_map[key])
190:         end

sti_load(r)

Return an instance of the class specified by sti_key, used by the row_proc.

[Source]

     # File lib/sequel/plugins/single_table_inheritance.rb, line 183
183:         def sti_load(r)
184:           sti_class_from_sti_key(r[sti_key]).call(r)
185:         end

sti_subclass_added(key)

Make sure that all subclasses of the parent class correctly include keys for all of their descendant classes.

[Source]

     # File lib/sequel/plugins/single_table_inheritance.rb, line 194
194:         def sti_subclass_added(key)
195:           if sti_key_array
196:             key_array = Array(key)
197:             Sequel.synchronize{sti_key_array.push(*key_array)}
198:             superclass.sti_subclass_added(key)
199:           end
200:         end