module Sequel::Plugins::ClassTableInheritance::ClassMethods

Attributes

cti_ignore_subclass_columns[R]

An array of columns that may be duplicated in sub-classes. The primary key column is always allowed to be duplicated

cti_instance_dataset[R]

The dataset that table instance datasets are based on. Used for database modifications

cti_models[R]

An array of each model in the inheritance hierarchy that is backed by a new table.

cti_table_columns[R]

An array of column symbols for the backing database table, giving the columns to update in each backing database table.

cti_table_map[R]

A hash with class name symbol keys and table name symbol values. Specified with the :table_map option to the plugin, and should be used if the implicit naming is incorrect.

cti_tables[R]

An array of table symbols that back this model. The first is table symbol for the base model, and the last is the current model table symbol.

Public Instance Methods

cti_table_name() click to toggle source

The name of the most recently joined table.

    # File lib/sequel/plugins/class_table_inheritance.rb
320 def cti_table_name
321   cti_tables ? cti_tables.last : dataset.first_source_alias
322 end
freeze() click to toggle source

Freeze CTI information when freezing model class.

Calls superclass method
    # File lib/sequel/plugins/class_table_inheritance.rb
243 def freeze
244   @cti_models.freeze
245   @cti_tables.freeze
246   @cti_table_columns.freeze
247   @cti_table_map.freeze
248   @cti_ignore_subclass_columns.freeze
249 
250   super
251 end
inherited(subclass) click to toggle source
Calls superclass method
    # File lib/sequel/plugins/class_table_inheritance.rb
255 def inherited(subclass)
256   ds = sti_dataset
257 
258   # Prevent inherited in model/base.rb from setting the dataset
259   subclass.instance_exec { @dataset = nil }
260 
261   super
262 
263   # Set table if this is a class table inheritance
264   table = nil
265   columns = nil
266   if (n = subclass.name) && !n.empty?
267     if table = cti_table_map[n.to_sym]
268       columns = db.from(table).columns
269     else
270       table = subclass.implicit_table_name
271       columns = check_non_connection_error(false){db.from(table).columns}
272       table = nil if !columns || columns.empty?
273     end
274   end
275   table = nil if table && (table == cti_table_name)
276 
277   return unless table
278 
279   pk = primary_key
280   subclass.instance_exec do
281     if cti_tables.length == 1
282       ds = ds.select(*self.columns.map{|cc| Sequel.qualify(cti_table_name, Sequel.identifier(cc))})
283     end
284     cols = (columns - [pk]) - cti_ignore_subclass_columns
285     dup_cols = cols & ds.columns
286     unless dup_cols.empty?
287       raise Error, "class_table_inheritance with duplicate column names (other than the primary key column) is not supported, make sure tables have unique column names (duplicate columns: #{dup_cols}). If this is desired, specify these columns in the :ignore_subclass_columns option when initializing the plugin"
288     end
289     sel_app = cols.map{|cc| Sequel.qualify(table, Sequel.identifier(cc))}
290     @sti_dataset = ds = ds.join(table, pk=>pk).select_append(*sel_app)
291 
292     ds = ds.from_self(:alias=>@cti_alias)
293 
294     set_dataset(ds)
295     set_columns(self.columns)
296     @dataset = @dataset.with_row_proc(lambda{|r| subclass.sti_load(r)})
297     cols.each{|a| define_lazy_attribute_getter(a, :dataset=>dataset, :table=>@cti_alias)}
298 
299     @cti_models += [self]
300     @cti_tables += [table]
301     @cti_table_columns = columns
302     @cti_instance_dataset = db.from(table)
303 
304     cti_tables.reverse_each do |ct|
305       db.schema(ct).each{|sk,v| db_schema[sk] = v}
306     end
307   end
308 end
sti_class_from_key(key) click to toggle source

The model class for the given key value.

    # File lib/sequel/plugins/class_table_inheritance.rb
325 def sti_class_from_key(key)
326   sti_class(sti_model_map[key])
327 end
table_name() click to toggle source

The table name for the current model class's main table.

Calls superclass method
    # File lib/sequel/plugins/class_table_inheritance.rb
311 def table_name
312   if cti_tables && cti_tables.length > 1
313     @cti_alias
314   else
315     super
316   end
317 end

Private Instance Methods

sti_subclass_dataset(key) click to toggle source

If using a subquery for class table inheritance, also use a subquery when setting subclass dataset.

Calls superclass method
    # File lib/sequel/plugins/class_table_inheritance.rb
333 def sti_subclass_dataset(key)
334   ds = super
335   if cti_models[0] != self
336     ds = ds.from_self(:alias=>@cti_alias)
337   end
338   ds
339 end