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Module: Rails::Generators::Migration

Relationships & Source Files
Namespace Children
Modules:
Extension / Inclusion / Inheritance Descendants
Included In:
Super Chains via Extension / Inclusion / Inheritance
Class Chain:
Defined in: railties/lib/rails/generators/migration.rb

Overview

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_number method.

Class Method Summary

::ActiveSupport::Concern - Extended

class_methods

Define class methods from given block.

included

Evaluate given block in context of base class, so that you can write class macros here.

prepended

Evaluate given block in context of base class, so that you can write class macros here.

append_features, prepend_features

Instance Attribute Summary

Instance Method Summary

Instance Attribute Details

#migration_class_name (readonly)

[ GitHub ]

  
# File 'railties/lib/rails/generators/migration.rb', line 13

attr_reader :migration_number, :migration_file_name, :migration_class_name

#migration_file_name (readonly)

[ GitHub ]

  
# File 'railties/lib/rails/generators/migration.rb', line 13

attr_reader :migration_number, :migration_file_name, :migration_class_name

#migration_number (readonly)

[ GitHub ]

  
# File 'railties/lib/rails/generators/migration.rb', line 13

attr_reader :migration_number, :migration_file_name, :migration_class_name

Instance Method Details

#create_migration(destination, data, config = {}, &block)

[ GitHub ]

  
# File 'railties/lib/rails/generators/migration.rb', line 35

def create_migration(destination, data, config = {}, &block)
  action Rails::Generators::Actions::CreateMigration.new(self, destination, block || data.to_s, config)
end

#migration_template(source, destination, config = {})

Creates a migration template at the given destination. The difference to the default template method is that the migration number is prepended to the destination file name.

The migration number, 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"
[ GitHub ]

  
# 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)

  dir, base = File.split(destination)
  numbered_destination = File.join(dir, ["%migration_number%", base].join("_"))

  file = create_migration numbered_destination, nil, config do
    ERB.new(::File.binread(source), trim_mode: "-", eoutvar: "@output_buffer").result(binding)
  end
  Rails::Generators.add_generated_file(file)
end

#set_migration_assigns!(destination)

[ GitHub ]

  
# 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