Could not find generator - custom generator for my engine - ruby-on-rails

I have written some custom generators for my engine to simplify my work.
I want to generate some files direct into my engine.
However the generator is accessible only from the dummy app and not direct from the engine.
my_engine_root:# rails g custom_generator
Could not find generator custom_generator.
engine_dummy_path:# rails g custom_generator
Everything works...
I tried to require the generators path, but nothing worked. What am I doing wrong?

First of all, isolate your custom generator to a separated engine, so you can add this excerpt to "script/rails" or "bin/rails", depending on rails version, in the engine which you want the generators available:
ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../../Gemfile', __FILE__)
require 'bundler/setup' if File.exists?(ENV['BUNDLE_GEMFILE'])
then add rails, your custom generator gem and all dependencies to the Gemfile of your engine
gem 'rails', '~> 4.0.2'
gem 'my_custom_generator', :path => "/path/to/my_custom_generator"

Related

Rails 5 Require a dependent gem conditionally in a gem

We are writing a gem that includes multiple common gems used in a couple of our apps. We want to be able to have some kind of config to require or not require a certain gems. But the application.rb or enviroment.rb/*rb is loaded after gems is loaded. So we can not set a config there. The following way works but its not a good idea and I was wondering if there is a cleaner way to do this
bin/rails . (In consuming app)
#!/usr/bin/env ruby
DISABLE_TRANSPORT = true
APP_PATH = File.expand_path('../config/application', __dir__)
require_relative '../config/boot'
require 'rails/commands'
Gemfile (In consuming app)
gem 'fruit_chain'
fruit_chain/lib/fruit_chain.rb (Our gem)
require analytic
require transport unless defined?(DISABLE_TRANSPORT) && DISABLE_TRANSPORT
require marketing
...
module FruitChain
end
I'm not sure to understand what you want exactly... however, use require: false in the Gemfile may help you ?
# Gemfile
gem 'my_super_gem', require: false
And in an initializer you require them:
# config/initializer/fruit_chain.rb
require 'my_super_gem'
I've encountered the same problem and have only thought to include the gems explicitly as a responsibility of the app, and then injecting that gem into the parent gem through a configuration, and ensuring they conform to the same interface.

Minitest-Rails Spec-Style Tests by Default

Question: Using Rails 5 & Minitest-Rails is there a way to default new Rails apps to default to Spec-style testing?
I teach TDD and it's annoying to have to have the students convert each time we make a new app.
You could create a template.rb file with following configuration:
gem_group :development, :test do
gem "rspec-rails"
end
after_bundle do
`rails g rspec:install`
end
And then build a new Rails project using the following command
rails new my_app -T -m /path/to/template.rb
It will build a new Rails application, add Rails RSpec gem to its Gemfile and execute the install step for RSpec.
Otherwise you could provide a pre-built Rails Git repository and build on top of that.
References:
Rails Application Templates — Ruby on Rails Guides
rspec/rspec-rails: RSpec for Rails-3+
Looks like you've already done the hard work of answering your question. Though if you're teaching a class with an opinionated group of test gems, and a modified test_helper.rb and a modified application.rb, you may wish to consider writing your own gem that your students can add to their Gemfile. The gem could have the test gems you want as dependencies, and then they can install everything else they need with something like:
bin/rails generate <gem_name>:install
Here's a gem I wrote that you can fork or modify or just use as inspiration.
https://github.com/schadenfred/testable
I actually stole your config code for the above gem, which you can see expressed in inside a generator that lives here:
lib/generators/installer/install_generator.rb
It looks like in config/application.rb you just have to add:
config.generators do |g|
g.test_framework :minitest, spec: true
end
However there's not an automatic way to make Minitest-Rails default to spec style testing.
I could go to rspec, but would rather stay with Minitest for the moment as we teach our students Minitest from the beginning.
Ok so #sonna had 90% of what I was looking for.
I ended up with help creating a .railsrc file with
-d postgresql
-m ~/.template.rb
And a template with:
# .template.rb
# Gems we've talked about in class, but which have absolutely nothing to do
# with setting up spec-style testing.
# Included here for convenience.
gem_group :development do
# Improve the error message you get in the browser
gem 'better_errors'
# Use pry for rails console
gem 'pry-rails'
end
# Add some extra minitest support
gem_group :test do
gem 'minitest-rails'
gem 'minitest-reporters'
end
# Add some code to some files to support spec-style testing
# For these injections, indentation matters!
inject_into_file 'config/application.rb', after: "class Application < Rails::Application\n" do
<<-'RUBY'
# Force new test files to be generated in the minitest-spec style
config.generators do |g|
g.test_framework :minitest, spec: true
end
RUBY
end
# Things to do after all the gems have been installed
after_bundle do
# Run rails generate minitest:install
generate "minitest:install", "--force"
# Add minitest reporters support. This must be run after
# rails generate minitest:install, because that command
# changes test/test_helper.rb
inject_into_file 'test/test_helper.rb', after: 'require "minitest/rails"' do
<<-'RUBY'
require "minitest/reporters" # for Colorized output
# For colorful output!
Minitest::Reporters.use!(
Minitest::Reporters::SpecReporter.new,
ENV,
Minitest.backtrace_filter
)
RUBY
end
end
This sets up my project with postgres for DB, and Minitest-rails using spec-style tests and includes minitest-reporters.

how to add dependency in engines rails 4

I'm trying to add a gem depency in my engine but it does not work.
Here is my setting.
1- admin.gemspec
s.add_dependency "font-awesome-rails"
2- lib/admin.rb
require "admin/engine"
require "font-awesome-rails"
module Admin
end
But when i try to use the gem function in the engine, I got a NoMethodError
Has this changed in rails 4 ?
I'm assuming this is a mountable engine? It worked for me in a non-mountable one, but I'm running into the same issue and noticed (without resolution):
https://github.com/bokmann/font-awesome-rails/issues?q=engine
Looks like we're all rolling our own admin tools these days...

What does "configure the gem in the config block of config/environment.rb" mean?

I'm writing my first Rails app. The app uses a lot of enumerations, so I'd like to include this gem that makes it easier to work with them.
I'm stumped by the installation instructions, though, which say
[...] For a rails application configure the gem in the config block of
the config/environment.rb file
config.gem "enumerated_attribute"
In my config/environment.rb I don't see anything that looks like a "config block".
config/environment.rb:
# Load the rails application
require File.expand_path('../application', __FILE__)
# Initialize the rails application
Webtet::Application.initialize!
So what does the author mean when he writes "configure the gem in the config block"?
Does he just want me to include this line in config/environment.rb
config.gem "enumerated_attribute"
?
Looks like this setup instruction was written for rails 2 application. If this gem works with rails 3 you just should add gem 'enumerated_attribute' to your Gemfile. Also you can try to use https://github.com/brainspec/enumerize gem (it works with rails 3 and has SimpleForm, Formtastic support and other awesome features)

How to run a Rails application within a gem?

I'm not sure if this sort of thing is very common, but I keep finding myself trying to create gems that are just wrappers around a Rails application.
My gem will have a generator to create a config.ru but the Rails application will live inside the gem's lib directory. I need to know how to "embed" a Rails application and configure it so that it can be run inside the gem.
For example:
$ mygem new project
mygem created a directory called "project" with the following files:
project/config.ru
project/widgets/
project/foobars/
My gem will also generate some directories that will need to be added to Rails somehow so that I can access the code in those directories from the Rails app living inside the Gem.
Any help or advice you can give me would be appreciated.
To clarify, I'm not trying to create a Rails engine, or plugin to a Rails application. I'm trying to create a fully-fledged Rails application, but package it as a gem so that a user of my gem can run the gem (the rails app) without needing to know that it's using Rails behind the scenes.
Update: Okay, I've got a little bit working now. I've created the gem and generated the rails project inside the gem's lib directory.
$ bundle gem my_gem && cd my_gem/lib
$ rails new my_gem --skip-bundle
Which leaves me with:
my_gem/
my_gem.gemspec
bin/my_gem
lib/
my_gem.rb
my_gem/
version.rb # generated by bundler
# the rails app:
app/
config/
Gemfile
...etc
Since this gem requires Rails, I started adding the gems defined in the Rails Gemfile as dependencies in the gem's Gemspec, but I'm a little confused as to how to handle the assets group in the Gemfile.
# Rails Gemfile
group :assets do
gem 'sass-rails', '~> 3.2.3'
gem 'coffee-rails', '~> 3.2.1'
gem 'therubyracer', :platforms => :ruby
gem 'uglifier', '>= 1.0.3'
end
# gemspec
Gem::Specification.new do |gem|
gem.name = "my_gem"
# ...
gem.add_dependency 'rails', '3.2.8'
gem.add_dependency 'sqlite3'
gem.add_dependency 'jquery-rails'
# how to add the assets group gems?
end
Try this and see if it helps you make progress.
Gems are just directories of files, and you can put whatever files you want into a gem.
Create:
Create a blank gem full-blown Rails project:
$ bundle gem my_gem
Then a Rails app:
$ rails new my_app --skip-bundle
Copy the Rails files into the gem:
$ cp -R my_app/* my_gem
Bundle everything into your Rails app:
$ cd my_gem
$ bundle install --binstubs --path vendor/bundle
$ cd -
Make the Rakefile have the gem tasks and the Rails setup:
#!/usr/bin/env rake
require "bundler/gem_tasks"
require File.expand_path('../config/application', __FILE__)
MyApp::Application.load_tasks
Verify that it starts:
$ rails server
Load Path:
To control where Rails looks for files, such as "external" configuration files, you can use the file config/application.rb with any directory paths like this:
# Add additional load paths for your own custom dirs
# config.load_paths += %W( #{config.root}/../customdir )
Note the ".." which means go above the Rails directory. This gives you a path relative to the gem.
If you prefer you can specify an absolute path, for example if you know the user will always keep his external files in "~/myfiles/". You can also choose to use ENV vars to send in whatever directory you want.
If you read about load path capabilties, look for lines that are shorthand for adding a directory to the front of the load path because you may want to put your external diretories first:
$:.unshift File.dirname(__FILE__)
Gem Build:
Edit my_gem.gemspec to add your own description, homepage, summary, etc. then build:
$ gem build my_gem.gemspec
Successfully built RubyGem
Name: my_gem
Version: 0.0.1
File: my_gem-0.0.1.gem
Now your Rails app is packaged as a gem.
The config.ru should be a typical Rails one. No special changes AFAIK.
When your user wants to install your app:
$ gem install my_gem
The gem will install in the user's typical gem directory. If you want to adjust this, see this page on rubygems: http://docs.rubygems.org/read/chapter/3
Crate:
You may also want to investigate the Crate project:
Crate: Packaging Standalone Ruby Applications
http://www.slideshare.net/copiousfreetime/crate-packaging-standalone-ruby-applications
Rack:
To use config.ru here is the typical Rails setup:
# Rails.root/config.ru
require "config/environment"
use Rails::Rack::LogTailer
use ActionDispatch::Static
run ActionController::Dispatcher.new
For your project, you want to require some files before Rails. You'll want to learn about the Ruby "require" and how it finds files using LOAD_PATH.
The easy way:
# Rails.root/config.ru
require_relative 'filename'
require "config/environment"
Or to put the user's custom directory up couple directory levels:
require './../../filename' # not the best for security
Or to use an absolute path, read about File.expand_path:
File.expand_path(__FILE__)
Or to use the current directory and put it on the load path:
$LOAD_PATH.unshift(File.dirname(__FILE__))
require 'filename'
Lots of choices for you to consider. Hope this helps!
What about the question, "How am I going to run the Rails application inside the gem?".
A Rails application has controllers and views to run a web server. What you need are actions to create, list, update, and destroy. Exposing these actions without a web server is essentially having such methods in a class. That's a normal standard type of gem in the first place.
So maybe your questions is really, how do I write a gem where I have ActiveRecord, and the other Rails stuff.
First, you need to make your gem dependent on the Rails gems you need. You do this in the gemspec file for your gem.
Then it really is just a matter of your gem code doing a require of the right Rails gems you need.
I'm not sure if this will help, as I read through everything and I couldn't find the motivation behind why you were doing this. One of the reasons I came up with was making something that can be used on a desktop environment. In that case you could try using something like Bowline. If you just want to provide an application that others can download and use and install themselves, then you can probably assume they can follow at least basic developer kind of instructions and you could just provide the whole app on github or as a zip file. See an example of someone else doing something similar over on Fat Free CRM's github page.

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