ruby-on-rails - `next_migration_number' : NotImplementedError (NotImplementedError) using wysihat-engine in rails

Question

我正在使用以下 gem 作为编辑器。

gem "wysihat-engine", "~> 0.1.13"

当我运行“rails generate wysihat”时，它会生成所有图像文件，但无法生成迁移并给出以下错误

c:/Ruby193/lib/ruby/gems/1.9.1/gems/railties-3.2.3/lib/rails/generators/migration.rb:30:in `next_migration_number': NotImplementedError (NotImplementedError)
    from c:/Ruby193/lib/ruby/gems/1.9.1/gems/railties-3.2.3/lib/rails/generators/migration.rb:49:in `migration_template'
    from c:/Ruby193/lib/ruby/gems/1.9.1/gems/wysihat-engine-0.1.13/lib/generators/wysihat_generator.rb:60:in `install_wysihat'
    from c:/Ruby193/lib/ruby/gems/1.9.1/gems/thor-0.14.6/lib/thor/task.rb:22:in `run'
    from c:/Ruby193/lib/ruby/gems/1.9.1/gems/thor-0.14.6/lib/thor/invocation.rb:118:in `invoke_task'
    from c:/Ruby193/lib/ruby/gems/1.9.1/gems/thor-0.14.6/lib/thor/invocation.rb:124:in `block in invoke_all'
    from c:/Ruby193/lib/ruby/gems/1.9.1/gems/thor-0.14.6/lib/thor/invocation.rb:124:in `each'
    from c:/Ruby193/lib/ruby/gems/1.9.1/gems/thor-0.14.6/lib/thor/invocation.rb:124:in `map'
    from c:/Ruby193/lib/ruby/gems/1.9.1/gems/thor-0.14.6/lib/thor/invocation.rb:124:in `invoke_all'
    from c:/Ruby193/lib/ruby/gems/1.9.1/gems/thor-0.14.6/lib/thor/group.rb:226:in `dispatch'
    from c:/Ruby193/lib/ruby/gems/1.9.1/gems/thor-0.14.6/lib/thor/base.rb:389:in `start'
    from c:/Ruby193/lib/ruby/gems/1.9.1/gems/railties-3.2.3/lib/rails/generators.rb:170:in `invoke'
    from c:/Ruby193/lib/ruby/gems/1.9.1/gems/railties-3.2.3/lib/rails/commands/generate.rb:12:in `<top (required)>'
    from c:/Ruby193/lib/ruby/gems/1.9.1/gems/activesupport-3.2.3/lib/active_support/dependencies.rb:251:in `require'
    from c:/Ruby193/lib/ruby/gems/1.9.1/gems/activesupport-3.2.3/lib/active_support/dependencies.rb:251:in `block in require'
    from c:/Ruby193/lib/ruby/gems/1.9.1/gems/activesupport-3.2.3/lib/active_support/dependencies.rb:236:in `load_dependency'
    from c:/Ruby193/lib/ruby/gems/1.9.1/gems/activesupport-3.2.3/lib/active_support/dependencies.rb:251:in `require'
    from c:/Ruby193/lib/ruby/gems/1.9.1/gems/railties-3.2.3/lib/rails/commands.rb:29:in `<top (required)>'
    from script/rails:6:in `require'
    from script/rails:6:in `<main>'

谢谢你的帮助!

Answer 1

我刚刚在 Rails 4.1.5 中遇到了这个问题

我通过在我的迁移中实现来修复它:

class MigrationGenerator < ::Rails::Generators::Base
  include Rails::Generators::Migration

  private
  def self.next_migration_number(dirname)
    next_migration_number = current_migration_number(dirname) + 1
    ActiveRecord::Migration.next_migration_number(next_migration_number)
  end
end