How to solve has_paper_trail method missing in rails 3.2

[dukex]

This issues is how to solve a problem, please create a pull request to fix it or update the documentation.

Using rails 3.2 and paper_trail 5.0.0 I receive the following error:

.../activerecord-3.2.19/lib/active_record/dynamic_matchers.rb:55:in `method_missing': undefined local variable or method `has_paper_trail' for #<Class:0x007f339a7baaf0> (NameError)

To fix it, create an initiailizer and load the active record framework:

$ echo "require 'paper_trail/frameworks/active_record'" > config/initializers/paper_trail.rb

The problem was introducted by 2029ea3 in #725

[jaredbeck]

Are you using require: false in your Gemfile? For example:

gem "paper_trail", require: false

Can you provide a complete stack trace for the NameError? Thanks.

[dukex]

The Trace:

/home/duke/.gem/ruby/2.1.3/gems/activerecord-3.2.19/lib/active_record/dynamic_matchers.rb:55:in `method_missing': undefined local variable or method `has_paper_trail' for #<Class:0x007faa7138
f2e8> (NameError)
        from /src/xproject/app/models/system.rb:140:in `<class:System>'
        from /src/xproject/app/models/system.rb:90:in `<top (required)>'
        from /home/duke/.gem/ruby/2.1.3/gems/activesupport-3.2.19/lib/active_support/dependencies.rb:469:in `load'
        from /home/duke/.gem/ruby/2.1.3/gems/activesupport-3.2.19/lib/active_support/dependencies.rb:469:in `block in load_file'
        from /home/duke/.gem/ruby/2.1.3/gems/activesupport-3.2.19/lib/active_support/dependencies.rb:639:in `new_constants_in'
        from /home/duke/.gem/ruby/2.1.3/gems/activesupport-3.2.19/lib/active_support/dependencies.rb:468:in `load_file'
        from /home/duke/.gem/ruby/2.1.3/gems/activesupport-3.2.19/lib/active_support/dependencies.rb:353:in `require_or_load'
        from /home/duke/.gem/ruby/2.1.3/gems/activesupport-3.2.19/lib/active_support/dependencies.rb:502:in `load_missing_constant'
        from /home/duke/.gem/ruby/2.1.3/gems/activesupport-3.2.19/lib/active_support/dependencies.rb:192:in `block in const_missing'
        from /home/duke/.gem/ruby/2.1.3/gems/activesupport-3.2.19/lib/active_support/dependencies.rb:190:in `each'
        from /home/duke/.gem/ruby/2.1.3/gems/activesupport-3.2.19/lib/active_support/dependencies.rb:190:in `const_missing'
        from /src/xproject/config/initializers/rails_admin.rb:93:in `block in <top (required)>'
        from /home/duke/.gem/ruby/2.1.3/bundler/gems/rails_admin-992d962d65f2/lib/rails_admin.rb:29:in `call'
        from /home/duke/.gem/ruby/2.1.3/bundler/gems/rails_admin-992d962d65f2/lib/rails_admin.rb:29:in `config'
        from /src/xproject/config/initializers/rails_admin.rb:4:in `<top (required)>'
        from /home/duke/.gem/ruby/2.1.3/gems/activesupport-3.2.19/lib/active_support/dependencies.rb:245:in `load'
        from /home/duke/.gem/ruby/2.1.3/gems/activesupport-3.2.19/lib/active_support/dependencies.rb:245:in `block in load'
        from /home/duke/.gem/ruby/2.1.3/gems/activesupport-3.2.19/lib/active_support/dependencies.rb:236:in `load_dependency'
        from /home/duke/.gem/ruby/2.1.3/gems/activesupport-3.2.19/lib/active_support/dependencies.rb:245:in `load'
        from /home/duke/.gem/ruby/2.1.3/gems/railties-3.2.19/lib/rails/engine.rb:593:in `block (2 levels) in <class:Engine>'
        from /home/duke/.gem/ruby/2.1.3/gems/railties-3.2.19/lib/rails/engine.rb:592:in `each'
        from /home/duke/.gem/ruby/2.1.3/gems/railties-3.2.19/lib/rails/engine.rb:592:in `block in <class:Engine>'
        from /home/duke/.gem/ruby/2.1.3/gems/railties-3.2.19/lib/rails/initializable.rb:30:in `instance_exec'
        from /home/duke/.gem/ruby/2.1.3/gems/railties-3.2.19/lib/rails/initializable.rb:30:in `run'
        from /home/duke/.gem/ruby/2.1.3/gems/railties-3.2.19/lib/rails/initializable.rb:55:in `block in run_initializers'
        from /home/duke/.gem/ruby/2.1.3/gems/railties-3.2.19/lib/rails/initializable.rb:54:in `each'
        from /home/duke/.gem/ruby/2.1.3/gems/railties-3.2.19/lib/rails/initializable.rb:54:in `run_initializers'
        from /home/duke/.gem/ruby/2.1.3/gems/railties-3.2.19/lib/rails/application.rb:136:in `initialize!'
        from /home/duke/.gem/ruby/2.1.3/gems/railties-3.2.19/lib/rails/railtie/configurable.rb:30:in `method_missing'
        from /src/xproject/config/environment.rb:6:in `<top (required)>'
        from /home/duke/.gem/ruby/2.1.3/gems/activesupport-3.2.19/lib/active_support/dependencies.rb:251:in `require'
        from /home/duke/.gem/ruby/2.1.3/gems/activesupport-3.2.19/lib/active_support/dependencies.rb:251:in `block in require'
        from /home/duke/.gem/ruby/2.1.3/gems/activesupport-3.2.19/lib/active_support/dependencies.rb:236:in `load_dependency'
        from /home/duke/.gem/ruby/2.1.3/gems/activesupport-3.2.19/lib/active_support/dependencies.rb:251:in `require'
        from /home/duke/.gem/ruby/2.1.3/gems/spring-1.6.4/lib/spring/application.rb:92:in `preload'
        from /home/duke/.gem/ruby/2.1.3/gems/spring-1.6.4/lib/spring/application.rb:143:in `serve'

My Gemfile:

gem 'paper_trail' # implementa auditoria para os modelos

[batter]

Are you declaring has_paper_trail at class or instance level? Can you share your System model?

[jaredbeck]

Given that your Gemfile requires PT, here's what I expect to happen:

application.rb loads your bundle, which calls `require "paper_trail"`
  paper_trail.rb requires paper_trail/has_paper_trail.rb which defines `PaperTrail::Model`
  paper_trail.rb requires paper_trail/frameworks/active_record.rb
    active_record.rb defines an `on_load` callback to `include PaperTrail::Model`
the `on_load` callback happens
finally, your environment.rb is run

This is based on my vague understanding of the rails boot process, and could be totally wrong, or could have changed between rails 3 and rails 4.

Our next step should be to reproduce this issue in a brand new rails app without rails_admin. If we can do that, then we can fire up a debugger and see if I'm right about the boot process.

[Skulli]

I am having a similar problem with my rails 4.2.6 setup here.

gems/activerecord-4.2.6/lib/active_record/dynamic_matchers.rb:26:in `method_missing': undefined local variable or method `has_paper_trail' for Client (call 'Client.connection' to establish a connection):Class (NameError)
from app/models/client.rb:4:in `<class:Client>'
from app/models/client.rb:3:in `<top (required)>'

[jaredbeck]

I have reproduced this issue in a new rails app: https://github.com/jaredbeck/pt_issue_789

The problem can be reproduced when a custom initializer autoloads an AR model before the paper_trail.initialisation initializer has run.

[jaredbeck]

Closed by #794. Sascha and Duke, please try master and let me know if that solves your problem.

[jaredbeck]

This fix has been released in 5.0.1.

[dukex]

Thank you @jarebeck I'll try this version soon

[Skulli]

Thank you too, for me it's working with rails 4