72 lines
2.4 KiB
Ruby
72 lines
2.4 KiB
Ruby
|
# frozen_string_literal: true
|
||
|
|
||
|
require_relative "../migration_generator"
|
||
|
|
||
|
module PaperTrail
|
||
|
# Installs PaperTrail in a rails app.
|
||
|
class InstallGenerator < MigrationGenerator
|
||
|
# Class names of MySQL adapters.
|
||
|
# - `MysqlAdapter` - Used by gems: `mysql`, `activerecord-jdbcmysql-adapter`.
|
||
|
# - `Mysql2Adapter` - Used by `mysql2` gem.
|
||
|
MYSQL_ADAPTERS = [
|
||
|
"ActiveRecord::ConnectionAdapters::MysqlAdapter",
|
||
|
"ActiveRecord::ConnectionAdapters::Mysql2Adapter"
|
||
|
].freeze
|
||
|
|
||
|
source_root File.expand_path("templates", __dir__)
|
||
|
class_option(
|
||
|
:with_changes,
|
||
|
type: :boolean,
|
||
|
default: false,
|
||
|
desc: "Store changeset (diff) with each version"
|
||
|
)
|
||
|
|
||
|
desc "Generates (but does not run) a migration to add a versions table." \
|
||
|
" See section 5.c. Generators in README.md for more information."
|
||
|
|
||
|
def create_migration_file
|
||
|
add_paper_trail_migration("create_versions",
|
||
|
item_type_options: item_type_options,
|
||
|
versions_table_options: versions_table_options)
|
||
|
add_paper_trail_migration("add_object_changes_to_versions") if options.with_changes?
|
||
|
end
|
||
|
|
||
|
private
|
||
|
|
||
|
# MySQL 5.6 utf8mb4 limit is 191 chars for keys used in indexes.
|
||
|
# See https://github.com/paper-trail-gem/paper_trail/issues/651
|
||
|
def item_type_options
|
||
|
opt = { null: false }
|
||
|
opt[:limit] = 191 if mysql?
|
||
|
", #{opt}"
|
||
|
end
|
||
|
|
||
|
def mysql?
|
||
|
MYSQL_ADAPTERS.include?(ActiveRecord::Base.connection.class.name)
|
||
|
end
|
||
|
|
||
|
# Even modern versions of MySQL still use `latin1` as the default character
|
||
|
# encoding. Many users are not aware of this, and run into trouble when they
|
||
|
# try to use PaperTrail in apps that otherwise tend to use UTF-8. Postgres, by
|
||
|
# comparison, uses UTF-8 except in the unusual case where the OS is configured
|
||
|
# with a custom locale.
|
||
|
#
|
||
|
# - https://dev.mysql.com/doc/refman/5.7/en/charset-applications.html
|
||
|
# - http://www.postgresql.org/docs/9.4/static/multibyte.html
|
||
|
#
|
||
|
# Furthermore, MySQL's original implementation of UTF-8 was flawed, and had
|
||
|
# to be fixed later by introducing a new charset, `utf8mb4`.
|
||
|
#
|
||
|
# - https://mathiasbynens.be/notes/mysql-utf8mb4
|
||
|
# - https://dev.mysql.com/doc/refman/5.5/en/charset-unicode-utf8mb4.html
|
||
|
#
|
||
|
def versions_table_options
|
||
|
if mysql?
|
||
|
', { options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_general_ci" }'
|
||
|
else
|
||
|
""
|
||
|
end
|
||
|
end
|
||
|
end
|
||
|
end
|