Module: Schemer::Sequel::ClassMethods

Defined in:
lib/schemer/sequel.rb

Instance Method Summary collapse

Instance Method Details

#protected_columns ⇒ Object 



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# File 'lib/schemer/sequel.rb', line 32

def protected_columns
  @protected_columns = [ :id ].freeze
end

#schema(*args) ⇒ Object

Define a schema on your Sequel model.

schema :name, { :age => :integer }, { :birthdate => :datetime }, :summary

Table + columns will be added automatically based on your definition.

If you remove a column, it will be removed from the table the next time the class is loaded.

If you change the type of a column, it will be also be updated the next time the class is loaded.

Likewise, adding a new column will add the column to your schema on the next class load.

Columns with no types are assumed to be strings.



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# File 'lib/schemer/sequel.rb', line 22

def schema(*args)
  @schema_columns = {}
  
  args.collect{ |a| a.is_a?(Hash) ? a : { a => String } }.each do |column|
    self.schema_columns.merge!(column)
  end
  
  update_schema
end

#schema_columns ⇒ Object 



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# File 'lib/schemer/sequel.rb', line 36

def schema_columns
  @schema_columns
end

#update_schema ⇒ Object

Update the underlying schema as defined by schema call



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# File 'lib/schemer/sequel.rb', line 41

def update_schema        
  db.create_table?(self.table_name) do
    primary_key :id
  end
  
  get_db_schema.reject{ |column, definition| protected_columns.include?(column) }.each do |column, definition|
    if !schema_columns.has_key?(column)
      # remove any extraneous columns
      db.drop_column(table_name, column)
      
      # remove the accessors (sequel doesn't appear to have a facility
      # for this)
      [ "#{column}", "#{column}=" ].each do |method|
        overridable_methods_module.send(:undef_method, method) if public_instance_methods.include?(method)
      end
    elsif (definition[:type] || definition[:db_type]) != schema_columns[column]
      # change any columns w/ wrong type
      db.set_column_type(table_name, column, schema_columns[column])
    end
  end

  # add any missing columns
  (schema_columns.keys - columns).each do |column|
    db.add_column(table_name, column, schema_columns[column])
    def_column_accessor column          
  end
end