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_qualify_tables[R]

A boolean indicating whether or not to automatically qualify tables backing subclasses with the same qualifier as their superclass, if the superclass is qualified. Specified with the :qualify_tables option to the plugin and only applied to automatically determined table names (not to the :table_map option).

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
343 def cti_table_name
344   cti_tables ? cti_tables.last : dataset.first_source_alias
345 end
freeze() click to toggle source

Freeze CTI information when freezing model class.

Calls superclass method
    # File lib/sequel/plugins/class_table_inheritance.rb
259 def freeze
260   @cti_models.freeze
261   @cti_tables.freeze
262   @cti_table_columns.freeze
263   @cti_table_map.freeze
264   @cti_ignore_subclass_columns.freeze
265 
266   super
267 end
inherited(subclass) click to toggle source
Calls superclass method
    # File lib/sequel/plugins/class_table_inheritance.rb
271 def inherited(subclass)
272   ds = sti_dataset
273 
274   # Prevent inherited in model/base.rb from setting the dataset
275   subclass.instance_exec { @dataset = nil }
276 
277   super
278 
279   # Set table if this is a class table inheritance
280   table = nil
281   columns = nil
282   if (n = subclass.name) && !n.empty?
283     if table = cti_table_map[n.to_sym]
284       columns = db.schema(table).map(&:first)
285     else
286       table = if cti_qualify_tables && (schema = dataset.schema_and_table(cti_table_name).first)
287         SQL::QualifiedIdentifier.new(schema, subclass.implicit_table_name)
288       else
289         subclass.implicit_table_name
290       end
291       columns = check_non_connection_error(false){db.schema(table) && db.schema(table).map(&:first)}
292       table = nil if !columns || columns.empty?
293     end
294   end
295   table = nil if table && (table == cti_table_name)
296 
297   return unless table
298 
299   pk = primary_key
300   subclass.instance_exec do
301     if cti_tables.length == 1
302       ds = ds.select(*self.columns.map{|cc| Sequel.qualify(cti_table_name, Sequel.identifier(cc))})
303     end
304     ds.send(:columns=, self.columns)
305     cols = (columns - [pk]) - cti_ignore_subclass_columns
306     dup_cols = cols & ds.columns
307     unless dup_cols.empty?
308       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"
309     end
310     sel_app = cols.map{|cc| Sequel.qualify(table, Sequel.identifier(cc))}
311     @sti_dataset = ds = ds.join(table, pk=>pk).select_append(*sel_app)
312 
313     ds = ds.from_self(:alias=>@cti_alias)
314     ds.send(:columns=, self.columns + cols)
315 
316     set_dataset(ds)
317     set_columns(self.columns)
318     @dataset = @dataset.with_row_proc(lambda{|r| subclass.sti_load(r)})
319     cols.each{|a| define_lazy_attribute_getter(a, :dataset=>dataset, :table=>@cti_alias)}
320 
321     @cti_models += [self]
322     @cti_tables += [table]
323     @cti_table_columns = columns
324     @cti_instance_dataset = db.from(table)
325 
326     cti_tables.reverse_each do |ct|
327       db.schema(ct).each{|sk,v| db_schema[sk] = v}
328     end
329     setup_auto_validations if respond_to?(:setup_auto_validations, true)
330   end
331 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
348 def sti_class_from_key(key)
349   sti_class(sti_model_map[key])
350 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
334 def table_name
335   if cti_tables && cti_tables.length > 1
336     @cti_alias
337   else
338     super
339   end
340 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
356 def sti_subclass_dataset(key)
357   ds = super
358   if cti_models[0] != self
359     ds = ds.from_self(:alias=>@cti_alias)
360   end
361   ds
362 end