Module: Sequel::Plugins::ClassTableInheritance::ClassMethods

Defined in:
lib/sequel/plugins/class_table_inheritance.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#cti_instance_datasetObject (readonly)

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


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# File 'lib/sequel/plugins/class_table_inheritance.rb', line 223

def cti_instance_dataset
  @cti_instance_dataset
end

#cti_modelsObject (readonly)

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


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# File 'lib/sequel/plugins/class_table_inheritance.rb', line 215

def cti_models
  @cti_models
end

#cti_table_columnsObject (readonly)

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


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# File 'lib/sequel/plugins/class_table_inheritance.rb', line 219

def cti_table_columns
  @cti_table_columns
end

#cti_table_mapObject (readonly)

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.


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# File 'lib/sequel/plugins/class_table_inheritance.rb', line 233

def cti_table_map
  @cti_table_map
end

#cti_tablesObject (readonly)

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.


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# File 'lib/sequel/plugins/class_table_inheritance.rb', line 228

def cti_tables
  @cti_tables
end

Instance Method Details

#cti_table_nameObject

The name of the most recently joined table.


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# File 'lib/sequel/plugins/class_table_inheritance.rb', line 312

def cti_table_name
  cti_tables ? cti_tables.last : dataset.first_source_alias
end

#freezeObject

Freeze CTI information when freezing model class.


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# File 'lib/sequel/plugins/class_table_inheritance.rb', line 236

def freeze
  @cti_models.freeze
  @cti_tables.freeze
  @cti_table_columns.freeze
  @cti_table_map.freeze

  super
end

#inherited(subclass) ⇒ Object


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# File 'lib/sequel/plugins/class_table_inheritance.rb', line 247

def inherited(subclass)
  ds = sti_dataset

  # Prevent inherited in model/base.rb from setting the dataset
  subclass.instance_exec { @dataset = nil }

  super

  # Set table if this is a class table inheritance
  table = nil
  columns = nil
  if (n = subclass.name) && !n.empty?
    if table = cti_table_map[n.to_sym]
      columns = db.from(table).columns
    else
      table = subclass.implicit_table_name
      columns = check_non_connection_error(false){db.from(table).columns}
      table = nil if !columns || columns.empty?
    end
  end
  table = nil if table && (table == cti_table_name)

  return unless table

  pk = primary_key
  subclass.instance_exec do
    if cti_tables.length == 1
      ds = ds.select(*self.columns.map{|cc| Sequel.qualify(cti_table_name, Sequel.identifier(cc))})
    end
    cols = columns - [pk]
    dup_cols = cols & ds.columns
    unless dup_cols.empty?
      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"
    end
    sel_app = cols.map{|cc| Sequel.qualify(table, Sequel.identifier(cc))}
    @sti_dataset = ds = ds.join(table, pk=>pk).select_append(*sel_app)

    ds = ds.from_self(:alias=>@cti_alias)

    set_dataset(ds)
    set_columns(self.columns)
    @dataset = @dataset.with_row_proc(lambda{|r| subclass.sti_load(r)})
    cols.each{|a| define_lazy_attribute_getter(a, :dataset=>dataset, :table=>@cti_alias)}

    @cti_models += [self]
    @cti_tables += [table]
    @cti_table_columns = columns
    @cti_instance_dataset = db.from(table)

    cti_tables.reverse_each do |ct|
      db.schema(ct).each{|sk,v| db_schema[sk] = v}
    end
  end
end

#sti_class_from_key(key) ⇒ Object

The model class for the given key value.


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# File 'lib/sequel/plugins/class_table_inheritance.rb', line 317

def sti_class_from_key(key)
  sti_class(sti_model_map[key])
end

#table_nameObject

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


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# File 'lib/sequel/plugins/class_table_inheritance.rb', line 303

def table_name
  if cti_tables && cti_tables.length > 1
    @cti_alias
  else
    super
  end
end