Module: Rails::Generators::Migration

Extended by:
ActiveSupport::Concern
Defined in:
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 version method.

Defined Under Namespace

Modules: ClassMethods

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#migration_class_name ⇒ Object (readonly)

Returns the value of attribute migration_class_name.



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

def migration_class_name
  @migration_class_name
end

#migration_file_name ⇒ Object (readonly)

Returns the value of attribute migration_file_name.



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

def migration_file_name
  @migration_file_name
end

#migration_number ⇒ Object (readonly)

Returns the value of attribute migration_number.



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

def migration_number
  @migration_number
end

Instance Method Details

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



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# File '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 = {}) ⇒ Object

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"



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# File '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("_"))

  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
end

#set_migration_assigns!(destination) ⇒ Object 



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# File '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