Module: AutoMigrations::ClassMethods

Defined in:
lib/auto_migrations.rb

Instance Method Summary collapse

Instance Method Details

#auto_add_index(method, *args, &block) ⇒ Object 



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# File 'lib/auto_migrations.rb', line 106

def auto_add_index(method, *args, &block)      
  table_name = args.shift.to_s
  fields     = Array(args.shift).map(&:to_s)
  options    = args.shift

  index_name = options[:name] if options  
  index_name ||= "index_#{table_name}_on_#{fields.join('_and_')}"

  (self.indexes_in_schema ||= []) << index_name
  
  unless ActiveRecord::Base.connection.indexes(table_name).detect { |i| i.name == index_name }
    method_missing_without_auto_migration(method, *[table_name, fields, options], &block)
  end
end

#auto_create_table(method, *args) {|table_definition| ... } ⇒ Object

Yields:

  • (table_definition) 


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# File 'lib/auto_migrations.rb', line 59

def auto_create_table(method, *args, &block)
  table_name = args.shift.to_s    
  options    = args.pop || {}
    
  (self.tables_in_schema ||= []) << table_name

  # Table doesn't exist, create it
  unless ActiveRecord::Base.connection.tables.include?(table_name)
    return method_missing_without_auto_migration(method, *[table_name, options], &block)
  end

  # Grab database columns
  fields_in_db = ActiveRecord::Base.connection.columns(table_name).inject({}) do |hash, column|
    hash[column.name] = column
    hash
  end

  # Grab schema columns (lifted from active_record/connection_adapters/abstract/schema_statements.rb)
  table_definition = ActiveRecord::ConnectionAdapters::TableDefinition.new(ActiveRecord::Base.connection)
  table_definition.primary_key(options[:primary_key] || "id") unless options[:id] == false
  yield table_definition
  fields_in_schema = table_definition.columns.inject({}) do |hash, column|
    hash[column.name.to_s] = column
    hash
  end

  # Add fields to db new to schema
  (fields_in_schema.keys - fields_in_db.keys).each do |field|
    column = fields_in_schema[field]
    add_column table_name, column.name, column.type.to_sym, :limit => column.limit, :precision => column.precision, 
      :scale => column.scale, :default => column.default, :null => column.null
  end

  # Remove fields from db no longer in schema
  (fields_in_db.keys - fields_in_schema.keys & fields_in_db.keys).each do |field|
    column = fields_in_db[field]
    remove_column table_name, column.name
  end
  
  # Change field type if schema is different from db
  (fields_in_schema.keys & fields_in_db.keys).each do |field|
    if (field != 'id') && (fields_in_schema[field].type.to_sym != fields_in_db[field].type.to_sym)
      change_column table_name, fields_in_schema[field].name.to_sym, fields_in_schema[field].type.to_sym
    end
  end
end

#drop_unused_indexes ⇒ Object 



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# File 'lib/auto_migrations.rb', line 127

def drop_unused_indexes
  tables_in_schema.each do |table_name|
    indexes_in_db = ActiveRecord::Base.connection.indexes(table_name).map(&:name)
    (indexes_in_db - indexes_in_schema & indexes_in_db).each do |index_name|
      remove_index table_name, :name => index_name
    end
  end
end

#drop_unused_tables ⇒ Object 



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# File 'lib/auto_migrations.rb', line 121

def drop_unused_tables
  (ActiveRecord::Base.connection.tables - tables_in_schema - %w(schema_info schema_migrations)).each do |table|
    drop_table table
  end
end

#method_missing_with_auto_migration(method, *args, &block) ⇒ Object 



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# File 'lib/auto_migrations.rb', line 48

def method_missing_with_auto_migration(method, *args, &block)
  case method
  when :create_table
    auto_create_table(method, *args, &block)
  when :add_index
    auto_add_index(method, *args, &block)
  else
    method_missing_without_auto_migration(method, *args, &block) 
  end
end

#update_schema_version(version) ⇒ Object 



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# File 'lib/auto_migrations.rb', line 136

def update_schema_version(version)
  ActiveRecord::Base.connection.update("INSERT INTO schema_migrations VALUES ('#{version}')")
end