i have the following function that i make use of in a lot of my models. i use MongoID for MongoDB wrapper
def make_slug
self.slug = self.name.downcase.gsub(/[^a-z1-9]+/, '').chomp('')
end
Which is the best place to place it than copy and paste it in all my models.
Also any recommendation for a good Slug Gem for Rails4?
All models are Inherited from ActiveRecord, you can open the eigenclass to add a singleton method there and use in all models.
The method I'll choose would be putting it under lib directory and require it in each model I need it.
I guess you could do a mixin/module, which you include in your models where you need the functionality. Like this:
Example of the module:
module SlugMaker
def make_slug
# Do your magic here
end
end
And then include it in your model:
class SuperAwesomeModel
include SlugMaker
def some_action
make_slug
end
end
Related
Is there a proper place for helper methods for models in Rails? There are helper methods for controllers and views, but I'm not sure where the best place to put model helper methods. Aside from adding a method to ActiveRecord::Base, which I'd prefer not to.
UPDATE: It seems Concerns make a lot of sense. Here's an example of what I want. Certain models can never be deleted, so I add a callback that always throws an exception:
before_destroy :nope
def nope
raise 'Deleting not allowed'
end
With concerns, I could do something like this?
class MyModel < ActiveRecord::Base
include Undeletable
end
module Undeletable
extend ActiveSupport::Concern
included do
before_destroy :nope
end
def nope
raise 'Deleting not allowed'
end
end
Is this the Rails way of doing this?
If you want to use a helper_method my_helper_method inside a model, you can write
ApplicationController.helpers.my_helper_method
If you need a bit more flexibility, for example if you also need to override some methods, you can do this:
class HelperProxy < ActionView::Base
include ApplicationController.master_helper_module
def current_user
#let helpers act like we're a guest
nil
end
def self.instance
#instance ||= new
end
end
and then use with
HelperProxy.instance.my_helper_method
If you have strong nerves, you can also try to include the ApplicationController.master_helper_module directly into your model.
via : makandracards's post.
For your reference: http://railscasts.com/episodes/132-helpers-outside-views
If what you are asking is where to put code that is shared across multiple models in rails 4.2, then the standard answer has to be to use Concerns: How to use concerns in Rails 4
However, there are some good arguments (e.g. this) to just using standard rails module includes, and extends as marek-lipka suggests.
I would strongly recommend NOT using ApplicationController helper methods in a model, as you'll be importing a lot unnecessary baggage along with it. Doing so is usually a bad smell in my opinion, as it means you are not separating the MVC elements, and there is too much interdependency in your app.
If you need to modify a model object by adding a method that is just used within a view, then have a look at decorators. For example https://github.com/drapergem/draper
As my app is getting a bit big now, I'm trying to use namespacing to help organise my models a little better.
I've created a app/models/theme.rb file which will act as a gateway to the rest of the theme related models which will go in a theme subdirectory.
# app/models directory
theme.rb
theme/compiler.rb
theme/instance.rb
theme/revision.rb
Where instance.rb will start something like....
class Theme::Instance < ActiveRecord::Base
end
and theme.rb is simply...
class Theme
def initialize(args)
# some stuff here
end
end
But anytime I create a new model using a generator, it tries to overwrite a new theme.rb as per below.
rails g model theme::revision
#new theme.rb
module Theme
def self.table_name_prefix
'theme_'
end
end
I could just get rid of the module and copy the def self.table_name_prefix method to each class but that doesn't seem very DRY. I would like to use the table prefix as it keeps things more obvious in the DB. Is there a 'correct' Rails way of going about this that I've missed?
I guess the easiest way is to define Theme as a module that all classes extends
The Theme::Instance imply that the Instance class is contained in a Theme module.
As an alternative, you can create a ThemeUtils module that contains all common method that is included in each class, like a plugin in /lib
I am using Ruby on Rails 3.2.2 and I would like to "extract" some methods from my models / classes. That is, in more than one class / model I have some methods (note: methods are related to user authorizations and are named the "CRUD way") that are and work practically the same; so I thought that a DRY approach is to put those methods in a "shared" module or something like that.
What is a common and right way to accomplish that? For example, where (in which directories and files) should I put the "shared" code? how can I include mentioned methods in my classes / models? what do you advice about?
Note: I am looking for a "Ruby on Rails Way to make things".
One popular approach is to use ActiveSupport concerns. You would then place the common logic typically under app/concerns/ or app/models/concerns/ directory (based on your preference). An illustrative example:
# app/concerns/mooable.rb
module Mooable
extend ActiveSupport::Concern
included do
before_create :say_moo
self.mooables
where(can_moo: true)
end
end
private
def say_moo
puts "Moo!"
end
end
And in the model:
# app/models/cow.rb
class Cow < ActiveRecord::Base
include Mooable
end
In order to make it work this way you have to add the following line to config/application.rb
config.autoload_paths += %W(#{config.root}/app/concerns)
More information:
http://chris-schmitz.com/extending-activemodel-via-activesupportconcern/
http://blog.waxman.me/extending-your-models-in-rails-3
http://api.rubyonrails.org/classes/ActiveSupport/Concern.html
My answer has nothing to do with RoR directly but more with Ruby.
Shraing common code may be done in various ways in Ruby. In my opinion the most obvious way is to create Ruby Modules that contain the code and then include them inside your class/model. Those shared modules are frequently under the lib directory of your app root. For example:
# lib/authorizable.rb
module Authorizable
def method1
#some logic here
end
def method2
#some more logic here
end
end
# app/models/user.rb
class User < ActiveRecord::Base
include Authorizable
end
The User class may now invoke method1 and method2 which belong to the Authorizable module. You can include this module in any other Ruby class you'd like, this way you DRY your code.
I wrote an upsert method for one of my models. I would like all my models to have this upsert method. It seemed to me that the logical solution was to define a model that inherits from ActiveRecord::Base and then have all my other models inherit from that. But if I do that, Rails complains that the new model I created doesn't have a table to go with it, which is true, but I don't care.
Since the way I tried is apparently not the right way to do it, what's the right way to do it?
You can extend ActiveRecord with a module. you only do it in one place and it will be accessible for all models that inherits from ActiveRecord.
module YourModule
def self.included(recipient)
recipient.extend(ModelClassMethods)
recipient.class_eval do
include ModelInstanceMethods
end
end # #included directives
# Class Methods
module ModelClassMethods
# A method accessible on model classes
def whatever
end
end
# Instance Methods
module ModelInstanceMethods
#A method accessible on model instances
def another_one
end
end
end
#This is where your module is being included into ActiveRecord
if Object.const_defined?("ActiveRecord")
ActiveRecord::Base.send(:include, YourModule)
end
There are two ways to do this.
1) To have a parent model, but not need to create a table for it (i.e. an abstract class) you should set
class YourAbstractClass < ActiveRecord::Base
self.abstract_class = true
# rest of class code
end
2) Put the method in a module, that you include from all your models that need it (as in #Mark's answer)
You can move that method to a module and include that module in all the models that require that method.
Like I have this Utils module in lib folder of my app
module Utils
...
def to_name(ref)
ref.gsub('_', ' ').split.collect { |w| w.capitalize }.join(' ')
end
...
end
Then in my model, I say
class MyModel < AR::Base
include Utils
...
end
Probably, if you are using Rails 3, you should load the files in the lib folder by configuring your application.rb
config.autoload_paths += %W(#{config.root}/lib)
I have two models which need an identical function. I'd like to learn how to make this DRY the right rails way...
For both models I have:
before_save :assign_uuid
Which in each model has:
def assign_uuid
if self.uuid.nil?
self.uuid = ActiveSupport::SecureRandom.hex(32)
end
end
Since, assign_uuid lives in both models, Where is the one place I should place this func? Also, in the models, where it say's before_save. How do I call the assign_uuid in the location it is located?
Thanks
I'm no Ruby expert, so I'm not sure if this is frowned upon or not, but if I were you, I'd chuck it in a file in lib/ and whack it straight on ActiveRecord::Base with class_eval.
ActiveRecord::Base.class_eval do
def assign_uuid
if self.uuid.nil?
self.uuid = ActiveSupport::SecureRandom.hex(32)
end
end
end
That way, it's available for all your models. Either that, or create a miscellaneous model helpers file and include the module into the models you'd like.
# lib/misc_model_helpers.rb
module MiscModelHelpers
def assign_uuid
if self.uuid.nil?
self.uuid = ActiveSupport::SecureRandom.hex(32)
end
end
end
# models/person.rb
class Person < ActiveRecord::Base
include MiscModelHelpers
before_save :assign_uuid
end
Again, I'm really not 100% on the most rubyish way of doing this. It's probably something completely different. These are just two ways that work for me!
In your lib folder, add a file uuid_lib.rb, and write
module UuidLib
def assign_uuid
if self.uuid.nil?
self.uuid = ActiveSupport::SecureRandom.hex(32)
end
end
end
and inside your model write
include UuidLib
before_save :assign_uuid
An example article explaining modules and mixins in more detail can be found here.
You should add this as a module and mix it into your models, that is the Ruby way to do what you are after.