Install generator won't see a method I defined - ruby-on-rails

I'm trying to use my Engine in another app to test the install generator and it seems to be failing. I haven't used my install generator for a long time, so I'm not sure when it broke (or if it ever truly smoothly worked). My project is based off radar/forem, so I tried to borrow a lot of their code (including the generator).
Edit: My installer works for the engines test/dummy but not in other apps. Why?
GH issue: https://github.com/NJayDevelopment/mongoid_forums/issues/16
Here is the log:
$ rails g mongoid_forums:install
What is your user class called? [User]
What is the current_user helper called in your app? [current_user]
Defining mongoid_forums_user method inside ApplicationController...
insert app/controllers/application_controller.rb
Adding mongoid_forums initializer (config/initializers/mongoid_forums.rb)...
create config/initializers/mongoid_forums.rb
(erb):5:in `template': undefined method `per_page' for MongoidForums:Module (NoMethodError)
The route is successfully added, however the initializer/mongoid_forums.rb is a blank file. The method is defined exactly how radar/forem does it, what could be the error?
Here is the relevant code:
Per page method definition: https://github.com/NJayDevelopment/mongoid_forums/blob/master/lib/mongoid_forums.rb#L33
Mattr accessor:
https://github.com/NJayDevelopment/mongoid_forums/blob/master/lib/mongoid_forums.rb#L9
Initializer template:
https://github.com/NJayDevelopment/mongoid_forums/blob/master/lib/generators/mongoid_forums/install/templates/initializer.rb
Install generator at error point:
https://github.com/NJayDevelopment/mongoid_forums/blob/master/lib/generators/mongoid_forums/install_generator.rb#L47

Turns out when you try requiring mongoid_forums in pry, you'll see that an error involving decorators occurs. The issue is fixed here in my pull request to decorators: parndt/decorators#13
It's because of the way files are required and how load! is called over there.
Waiting on PR status, that is the same version that radar/forem uses as well.

Related

Monkey patching a db model class in Rails with Mongoid causes weird behaviour

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)

Conflict between Rails Admin and Impressionist gems

I'm using the latest version of the Impressionist and Rails Admin gems, and wondering if anyone could shed some light on an annoying conflict I'm experiencing. The problem is roughly documented here - https://github.com/sferik/rails_admin/issues/1315, yet the vaguely described solution is not working for me. When I have the line is_impressionable in my Listing model, I get an error when starting my Rails server with rails s:
...rvm/gems/ruby-2.0.0-p247/gems/activerecord-4.0.2/lib/active_record/dynamic_matchers.rb:22:in `method_missing': undefined local variable or method `is_impressionable' for Listing(no database connection):Class (NameError)
If I first start the server, and then add the 'is_impressionable' line, everything works fine, so the problem only occurs during initialization. I don't fully understand the initialization process, so am not sure how to go about getting this to work.
I have tried moving all my rails_admin model configuration options to their respective models, rather than in the initializer, which had no effect. I also have the following line in my initializer:
config.included_models = [Listing,ListingImage,AllOtherModelsHere...]
I have tried adding single quotes around these model names, which results in the following errors, as described in the github issue here
[RailsAdmin] Could not load model Listing, assuming model is non existing. (undefined local variable or method `is_impressionable' for Listing(no database connection):Class)
Any ideas what else I can try to make these gems work together? I don't want to have to remove the is_impressionable line every time I want to restart the server or generate a migration...
Not sure if the same issue that I had but yet I will post what worked for me just in case someone struggles with this too:
Im on a ruby 2.1.5 project with rails 4.2.0 and among other gems I'm using rails admin.
I run into several weird problems trying to set this up. For instance if I added the is_impressionable call within one of my models for some reason the execution of that file stopped there and I started getting weird errors like any method declared below the is_impressionable failed with undefined error.
So what I end up doing was:
class MyModel < ActiveRecord::Base
include Impressionist::IsImpressionable
is_impressionable
end
So this solved my issue and now i can access #my_model_instance.impression_count as expected.
I changed every occurrence of Klass to 'Klass'.constantize in initializer.

How to extend the String class in a command line app?

I primarily work in Rails and I'm using a command line data conversion gem, "Mongify" and I am stumped about how to extend core classes in a Ruby cli app.
I want to extend the String class with an .is_date? method to check whether a string can be converted to a Date. I've got it working in the Rails Console,
I added a string.rb file to lib/ext with the following;
class String
def is_date?
begin
return true if Date.parse(self)
rescue
#do nothing
end
return false
end
end
Then in a Rails console I do a require 'ext/string' and it will work.
But I can't figure out how to get it to work in the Mongify cli app. I copied string.rb into the lib folder of the gem and I've tried adding require 'string' to a number of different files in the gem, but I keep getting undefined method errors.
Can someone point me in the right direction?
How about you require it from lib/mongify.rb like so:
require 'string/extensions.rb'
And then put your code in lib/string/extensions.rb
Let us know the exact undefined method errors you're getting in case this isn't the solution.
To help you with the debugging exercise that would give you the answer you need. Start by putting a breakpoint right before the place of the function call.
In the debugger, load the required document and then step past your breakpoint to the next one after the call has occurred.
Once you have this working, then start earlier in the stack trace – in a file that loaded before that one. Keep moving backwards until you get to a sufficiently early part in the load process of the gem, and make that be the place you load your code.

'load_missing_constant' when trying to create an observer on Rails

I am trying to create an observer for my Offer model but I keep getting this error:
/Users/codus/.rvm/gems/ruby-1.9.3-p194#gyp/gems/activesupport-3.2.6/lib/active_support/dependencies.rb:503:in `load_missing_constant': Expected /Users/codus/Projetos/gyp-revolution/app/models/offer.rb to define Offer (LoadError)
There is nothing special about my model and I am sure it is declared in the right place (the application works fine without the observer).
I've generated my observer with the Rails script
rails g observer offer
And I added this in my config/application.rb file
config.active_record.observers = :offer_observer
The strangest part is that it works fine with all my other models.
I am using Rails 3.2.6 with Ruby 1.9.3p194.
The problem was that I was using FactoryGirl, and inside my Offer factory I called a constant defined in my model. The factory was being loaded before the model, so this error was happening.
It's weird that the observer changed this, it works fine without it. Now I just use the value in my factory, not the constant.

Having default Rails generators call a custom generator

To be clear, here's NOT what I'm trying to:
Have my custom generator call a default Rails generator
Replace a default Rails generator with my own
What I want to do is have my generator be invoked automatically when I call:
rails generate scaffold User name age:integer
I'm not writing a test replacement or anything, it's completely custom. All information I find about generators out there involve one of those first two cases but not what I want to do. As soon as I found hook_for I immediately thought that was exactly what I needed, but it appears to do the opposite -- invokes another Rails generator from inside of my custom one (if I wanted a test file created for my custom generator I'd call hook_for :test_framework and then define a TestUnit::MyCustomGenerator class somewhere).
I suppose I could monkey patch the default scaffold generator to call mine but that feels dirty. I've looked into some gems that do something similar like https://github.com/Skalar/i18n-yaml-generator but trying to convert that to use an initializer and lib/generators isn't working for me. The scaffold_generator runs but mine never gets called.
for me it works from lib/generators/
$ rails g generator scaffold
create lib/generators/scaffold
create lib/generators/scaffold/scaffold_generator.rb
create lib/generators/scaffold/USAGE
create lib/generators/scaffold/templates
$ rails g scaffold
Usage:
rails generate scaffold NAME [options]
....
what/will/it/create
http://guides.rubyonrails.org/generators.html#generators-lookup
another way may be :)
fork railties gem
override Rails::Generators::ScaffoldGenerator class to your liking
install locally or specify source path in Gemfile
also if 'its completely custom', it is just fair to call it a different name, no?

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