I'm trying to use modules for namespacing reasons. I have this file located in my Rails app at /lib/reports/stripe.rb.
module Reports
module Stripe
def self.foo
puts 'i am foo'
end
end
end
In my console, I'd expect to be able to call foo by Reports::Stripe.foo or Reports::Stripe::foo, but I get the error
NoMethodError: undefined method `foo' for Reports::Stripe:Module
What am I doing wrong? Also feel free to let me know if there's a better way to organize the location and namespacing.
All method calls in ruby use the . syntax. Even "module" methods.
> Reports::Stripe.foo
i am foo
You may be receiving the error NoMethodError: undefined method 'foo' for Reports::Stripe:Module if you have added the method after you have started the rails console. Try restarting the console or reloading the file with load 'reports/stripe'.
The file was actually located in /lib/reports/stripe/stripe.rb. It was a mistake I made much earlier, but forgot to fix. Moving the file to /lib/reports/stripe.rb resolved the issue.
Related
We are getting this error on all local setups of our project(currently) when we call any method like:
belongs_to :abc
after_create :some_method
def some_method
if self.abc.saved_change_to_parent_id?
...
// or even self.abc.parent_id_before_last_save
end
It gives:
NameError (undefined local variable or method `first' for ActiveRecord::NullMutationTracker:Class):
app/models/model_name.rb:50:in `some_method'
Yes, there is not a full trace with rails internal file paths etc, i only get my project files trace. Maybe its some logger config issue, any help to get full trace will also be appreciated.
There are no such issues i could find on internet, thats why posting here.
PS: Not posted on rails issue tracker(github issues) because i don't have minimal reproduction.
Stack
ruby: 2.4.3
rails: 5.1.5 (also tried on 5.1.7)
OS: Ubuntu 20, also tried on macOS
Thanks in advance.
UPDATE1: Using byebug, i got to this trace, where error is occuring:
/Users/dev/.rvm/gems/ruby-2.4.3/gems/acts_as_singleton-0.0.8/lib/acts_as_singleton.rb:43
which is here, so it is not directly from rails, but a very outdated gem we have in our code for some reason.
As i posted in the update, issue was not with rails or anything, i used byebug to track trace and it was something like:
activemodel-5.1.5/lib/active_model/attribute_methods.rb:384
activerecord-5.1.5/lib/active_record/attribute_methods/dirty.rb:146
activerecord-5.1.5/lib/active_record/attribute_methods/dirty.rb:319
activerecord-5.1.5/lib/active_record/attribute_methods/dirty.rb:315
acts_as_singleton-859f49112c03/lib/acts_as_singleton.rb:43
The last line, should not be there, as we are not using acts_as_singleton on any of the involved models.
So after some tracking, it turned out issue with the gem. I have created a fork and used that fork. Here is the fork: https://github.com/ziaulrehman40/acts_as_singleton (forked it from another fork, which seemingly had some other fixes as well). And you can see my changes here.
What was the issue?
This gem writes a module named Singleton within ActiveRecord module. Which seems ok, unless you realize that there is another module named Singleton already. Whihc is being included in:
gems/activerecord-5.1.5/lib/active_record/attribute_mutation_tracker.rb:83
class NullMutationTracker # :nodoc:
include Singleton
...
So as you can see, this Singleton module gets overriden(or expanded, not sure) un-intentionally by that outdated gem(acts_as_singleton).
I am using a development script file to check out new possible ideas. Recently I tried to monkey patch MyDBObject from within that script file.
Assume an empty dev.rb file and add a monkey patch right in the top like so:
class MyDBObject
def test_function
'function works'
end
end
Starting up the pry console and loading the file yields random results.
First I received:
NoMethodError: undefined method `relations' for MyDBObject:Class
Later the script loaded, but I couldn't access the original class any longer:
undefined method `first' for MyDBObject:Class
I noticed that prepending the line:
MyDBObject
right before the monkey patching, the intended functionality is achieved.
This appears to be some sort of lazy loading of the class objects. Can somebody cast some light on this for me please?
Depending on the order in which source files are loaded, you'll either be redefining the entire class, or having your changes replaced.
I highly recommend giving this a read: http://www.justinweiss.com/articles/3-ways-to-monkey-patch-without-making-a-mess/ (TLDR - put your patch in a module and explicitly include it)
I've followed this guide:
http://guides.rubyonrails.org/plugins.html#add-an-acts-as-method-to-active-record
In fact, I've actually copied the code and put into my app and it doesn't work.
I keep getting undefined method errors.
When I use console, I can check if the module is initialized and it is, but the model that uses the "acts_as" method throws undefined method errors.
Also in console I can call ActiveRecord::Base.send :include, ... explicitly and then it includes the module -- then everything works. But try as I may, I can't get rails to call .send on ActiveRecord::Base at load time.
Any ideas?
So, I have a standard rails 3 app with authlogic. If I'm not in the browser (in the console or in the test environment), I can't create user models.
For example:
I have this code either in a rspec test or in my console:
user = User.create(...user attributes...)
And I get this error:
NoMethodError: undefined method `cookies' for main:Object
I've looked all over the internet and can't figure this out. Any help would be greatly appreciated.
EDIT:
So, I looked around some more and found in the documentation to do this:
include Authlogic::TestCase
but then I get this error:
uninitialized constant Authlogic::TestCase
I had this same exact problem. Where in your application did you put the following line:
Authlogic::Session::Base.controller = Authlogic::ControllerAdapters::RailsAdapter.new(self)
I ran into this error when I placed the line in either the environment.rb file or within a file within my initializer folder.
I eliminated the problem when I placed the line in my ApplicationController instead.
In order to track activity in my application, I built a set of helpers which take in arrays of data and spit out .csv files. I want to use these from the console like so:
helper.export_data(array_of_data)
This works fine on my machine, but the heroku console doesn't seem to let me call helper functions. I receive the error:
NameError: undefined local variable or method `helper' for main:Object
I would guess here that your application is doing some sort of initialisation to get helper loaded into your console, and that that initialisation isn't occurring when you spin up a Heroku console.
Is there anything that you have done in your code which initialises this helper object?
Had same question, and found the answer here:
http://www.funonrails.com/2011/03/accessing-view-helpers-routes-in-rails.html
relevant part is:
>> include ActionView::Helpers
>> => Object
>> include ApplicationHelper
>> => Object
>> include ActionView::Helpers::ApplicationHelper^C
>> display_amount 2500 => "$2,500"