I'm using
Ruby version 1.8.7
Rails version 3.0.3
I have a method called alive in every model of my rails app:
def alive
where('deleter is null')
end
I don't want to copy this code in every model so I made a /lib/life_control.rb
module LifeControl
def alive
where('deleter is null')
end
def dead
where('deleter is not null')
end
end
and in my model (for example client.rb) I wrote:
class Client < ActiveRecord::Base
include LifeControl
end
and in my config/enviroment.rb I wrote this line:
require 'lib/life_control'
but now I get a no method error:
NoMethodError in
ClientsController#index
undefined method `alive' for
#<Class:0x10339e938>
app/controllers/clients_controller.rb:10:in
`index'
what am I doing wrong?
include will treat those methods as instance methods, not class methods. What you want to do is this:
module LifeControl
module ClassMethods
def alive
where('deleter is null')
end
def dead
where('deleter is not null')
end
end
def self.included(receiver)
receiver.extend ClassMethods
end
end
This way, alive and dead will be available on the class itself, not instances thereof.
I'm aware this is a pretty old question, the accepted answer did work for me, but that meant me having to re-write a lot of code because i have to change the module to a nested one.
This is what helped me with my situation and should work with most of today's applications.(not sure if it'll work in the ruby/rails version in the question)
instead of doing include use extend
So as per the question, the sample code would look like:
class Client < ActiveRecord::Base
extend LifeControl
end
Just put this line in application.rb file
config.autoload_paths += Dir["#{config.root}/lib/**/"]
Edited:
This line is working fine for me.
I want to suggest one more thing, ruby 1.8.x is not compatible with rails 3.x.
So just update your ruby for version 1.9.2
Following is my POC
In lib folder:
lib/test_lib.rb
module TestLib
def print_sm
puts "Hello World in Lib Directory"
end
end
In model file:
include TestLib
def test_method
print_sm
end
And In application.rb
config.autoload_paths += Dir["#{config.root}/lib/**/"]
Now you can call test_method like this in controller:
ModelName.new.test_method #####Hello World in Lib Directory
Related
I am using Solidus with Ruby on Rails to create a webshop and I have multiple modules for that webshop.
So, I defined a me controller into an module called 'solidus_jwt_auth' with the followin code:
module Spree
module Api
class MeController < Spree::Api::BaseController
def index
...
end
def orders
...
end
def addresses
...
end
end
end
end
I want to extend this in another module called 'solidus_prescriptions' so I created a decorator for this with the following code me_decorator:
if defined? Spree::Api::MeController.class
Spree::Api::MeController.class_eval do
def prescriptions
...
end
def create_prescription
...
end
private
def prescription_params
params.require(:prescription).permit(
*Spree::CustomerPrescription.permitted_attributes
)
end
end
end
And for this I wrote unit tests in solidus_prescription module and integration tests in webshop. The unit tests are working fine, but the integration tests are giving the following error:
Error:
MeEndpointsTest#test_me/prescriptions_post_endpoint_throws_an_error_when_wrong_params:
AbstractController::ActionNotFound: The action 'create_prescription' could not be found for Spree::Api::MeController
test/integration/me_endpoints_test.rb:68:in `block in '
Which means that he can not find the MeController defined in another module. How can I make the check if the MeController is defined since the code bellow does not help me with anything:
if defined? Spree::Api::MeController.class
end
This worked in the end:
def class_defined?(klass)
Object.const_get(klass)
rescue
false
end
if class_defined? 'Spree::Api::MeController'
....
end
if defined? should do exactly what you want it to do in theory. The problem is you're checking if defined? Spree::Api::MeController.class. The #class of your class is Class. So what you're really getting is if defined? Class which will always be true!
This issue is most likely not that the conditional is failing but that it's never getting read. Rails lazy loads most of the code you write, meaning the file is not read until it's called somewhere in execution.
The decorator module should just contain the methods you want to add, without the conditionals or the use of class_eval. Then in the original class you can include it.
module Spree
module Api
class MeController < Spree::Api::BaseController
include MeDecorator
end
end
end
If for any reason you're not certain MeDecorator will be defined, don't use defined?, because defined? MeDecorator will not actually go looking for it if it's not defined and load the necessary file. It will return nil if the constant has no value. Just rescue a NameError
module Spree
module Api
class MeController < Spree::Api::BaseController
begin
include MeDecorator
rescue NameError => e
logger.error e
end
end
end
end
I would like to setup a before_create for all of my modules
what i have been trying is:
module ActiveRecord
module UserMonitor
require 'securerandom'
before_create :attach_uuid
def attach_uuid
self.uuid = SecureRandom.uuid.gsub("-","")
end
end
end
This does not seem to be working.
if i go into each module and add it in there it works, but i want to do it on a global scale.
Any thoughts or ideas on how i can achieve this in this manner? i know i could do it in triggers and such but i don't want to go that route and i would like to avoid hitting every module/class in case i need to change something.
Currently using Ruby 1.9.3 Can not currently upgrade my app until i make future code changes.
Thanks!
An other solution - I use, is to put the logic for UUID in an own module, that you include. I already have some (class-) methods I add to my AR, like set_default_if, so it was a good place for me.
module MyRecordExt
def self.included base
base.extend ClassMethods # in my case some other stuff
base.before_create :attach_uuid # now add the UUID
end
def attach_uuid
begin
self.uuid = SecureRandom.uuid
rescue
# do the "why dont we have a UUID filed?" here
end
end
# some other things not needed for add_uuid
module ClassMethods
include MySpecialBase # just an eg.
def default_for_if(...)
...
end
end
end
and then
class Articel < ActiveRecord::Base
include MyRecordExt
...
end
In general I avoid doing something for ALL models modifying AR base - I made the first bad experience with adding the UUID to all, and crashed with devise GEMs models ...
If you define attach_uuid in the ActiveRecord module, can't you just call the before_create :attach_uuid at the top of each controller? This is DRY.
Is there a UserMonitor controller that you could add it to?
class UserMonitor < ActiveRecord::Base
before_create :attach_uuid
end
I have created a simple railtie, adding a bunch of stuff to ActiveRecord:
0 module Searchable
1 class Railtie < Rails::Railtie
2 initializer 'searchable.model_additions' do
3 ActiveSupport.on_load :active_record do
4 extend ModelAdditions
5 end
6 end
7 end
8 end
I require this file (in /lib) by adding the following line to config/environment.rb before the application is called:
require 'searchable'
This works great with my application and there are no major problems.
I have however encountered a problem with rake db:seed.
In my seeds.rb file, I read data in from a csv and populate the database. The problem I am having is that the additions I made to ActiveRecord don't get loaded, and seeds fails with a method_missing error. I am not calling these methods, but I assume that since seeds.rb loads the models, it tries to call some of the methods and that's why it fails.
Can anyone tell me a better place to put the require so that it will be included every time ActiveRecord is loaded (not just when the full application is loaded)? I would prefer to keep the code outside of my models, as it is code shared between most of my models and I want to keep them clean and DRY.
Putting the extend there just adds it to ActiveRecord::Base.
When a model class is referenced, via Rails 3.1 autoloading/constant lookup, it will load the class. At that point, it is pure Ruby (nothing magic) as to what happens, basically. So I think you have at least a few options. The "bad" option that kind of does what you want it to hook into dependency loading. Maybe something like:
module ActiveSupport
module Dependencies
alias_method(:load_missing_constant_renamed_my_app_name_here, :load_missing_constant)
undef_method(:load_missing_constant)
def load_missing_constant(from_mod, const_name)
# your include here if const_name = 'ModelName'
# perhaps you could list the app/models directory, put that in an Array, and do some_array.include?(const_name)
load_missing_constant_renamed_my_app_name_here(from_mod, const_name)
end
end
end
Another way to do it would be to use a Railtie like you were doing and add a class method to ActiveRecord::Base that then includes stuff, like:
module MyModule
class Railtie < Rails::Railtie
initializer "my_name.active_record" do
ActiveSupport.on_load(:active_record) do
# ActiveRecord::Base gets new behavior
include ::MyModule::Something # where you add behavior. consider using an ActiveSupport::Concern
end
end
end
end
If using an ActiveSupport::Concern:
module MyModule
module Something
extend ActiveSupport::Concern
included do
# this area is basically for anything other than class and instance methods
# add class_attribute's, etc.
end
module ClassMethods
# class method definitions go here
def include_some_goodness_in_the_model
# include or extend a module
end
end
# instance method definitions go here
end
end
Then in each model:
class MyModel < ActiveRecord::Base
include_some_goodness_in_the_model
#...
end
However, that isn't much better than just doing an include in each model, which is what I'd recommend.
I am developing a Rails engine to be packaged as a gem. In my engine's main module file, I have:
module Auditor
require 'engine' if defined?(Rails) && Rails::VERSION::MAJOR == 3
require 'application_controller'
end
module ActionController
module Auditor
def self.included(base)
base.extend(ClassMethods)
end
module ClassMethods
def is_audited
include ActionController::Auditor::InstanceMethods
before_filter :audit_request
end
end
module InstanceMethods
def audit_request
a = AuditorLog.new
a.save!
end
end
end
end
ActionController::Base.send(:include, ActionController::Auditor)
where AuditorLog is a model also provided by the engine. (My intent is to have "is_audited" added to the controllers in an application using this engine which will cause audit logging of the details of the request.)
The problem I have is that when this code gets called from an application where the engine is being used, the AuditorLog model isn't accessible. It looks like Ruby thinks it should be a class in ActionController:
NameError (uninitialized constant
ActionController::Auditor::InstanceMethods::AuditorLog)
rather than a model from my engine.
Can anyone point me in the right direction? This is my first time creating an engine and attempting to package it as a gem; I've searched for examples of this and haven't had much luck. My approach to adding this capability to the ActionController class was based on what mobile_fu does, so please let me know if I'm going about this all wrong.
Use ::AuditorLog to access the ActiveRecord class (unless you have it in a module or namespace, in which case you'll need to include the module name).
This is a definite newb question:
I have a module defined in my lib/ directory that I call from a sweeper and as a rake task. Inside the module I want to reference my spawn plugin. Just including methods from that plugin doesn't work (undefined method error), nor does any version of require or include that I've tried. What do I need to do to include it?
Thank you!
EDIT:
Here is my latest effort:
require 'vendor/plugins/spawn/init.rb'
module MyModule
include Spawn
def self.my_method
spawn(:method => :thread, :nice => 9) do # also tried Spawn::spawn
...
end
end
end
The error I get is:
undefined method 'spawn' for MyModule:Module #spawn or undefined method 'spawn' for Spawn:Module # Spawn::spawn
The including has to be done from within the plugin. When you "reopen" a module (which is in the lib/ dir), remember to require the original file before making changes to it (the module).
EDIT:
Considering that the plugin is third party, you could try:
Spawn.module_eval do
module_function :spawn
public :spawn
end
module MyModule
def self.my_method
Spawn.spawn(...)
end
end