Holds common methods for migrations. It assumes that migrations have the [0-9]*_name format and can be used by other frameworks (like Sequel) just by implementing the next migration version method.
Methods
Attributes
[R] | migration_class_name | |
[R] | migration_file_name | |
[R] | migration_number |
Instance Public methods
create_migration(destination, data, config = {}, &block) Link
migration_template(source, destination, config = {}) Link
Creates a migration template at the given destination. The difference to the default template method is that the migration version is appended to the destination file name.
The migration version, migration file name, migration class name are available as instance variables in the template to be rendered.
migration_template "migration.rb", "db/migrate/add_foo_to_bar.rb"
# File railties/lib/rails/generators/migration.rb, line 56 def migration_template(source, destination, config = {}) source = File.expand_path(find_in_source_paths(source.to_s)) set_migration_assigns!(destination) context = instance_eval("binding") dir, base = File.split(destination) numbered_destination = File.join(dir, ["%migration_number%", base].join("_")) file = create_migration numbered_destination, nil, config do if ERB.instance_method(:initialize).parameters.assoc(:key) # Ruby 2.6+ ERB.new(::File.binread(source), trim_mode: "-", eoutvar: "@output_buffer").result(context) else ERB.new(::File.binread(source), nil, "-", "@output_buffer").result(context) end end Rails::Generators.add_generated_file(file) end
set_migration_assigns!(destination) Link
# File railties/lib/rails/generators/migration.rb, line 39 def set_migration_assigns!(destination) destination = File.expand_path(destination, destination_root) migration_dir = File.dirname(destination) @migration_number = self.class.next_migration_number(migration_dir) @migration_file_name = File.basename(destination, ".rb") @migration_class_name = @migration_file_name.camelize end