I have around 50 admin models which have ModelAdmin as base class.Now I want to remove delete feature for all the 50 models. I think there are two ways.
Redefine has_delete_permission method to return false and remove 'delete_selected' action for all the 50 models (lot of work).
Do the same thing as mentioned above in django.contrib.admin.AdminModel. which means altering the source code.
I don't want to alter the sourcecode. Is their any other way to do this expect above two ways?
3 . Create a an admin mixin class that has these two adjustments, and add to base classes of your existing 50 ModelAdmins
4 . Monkeypatch ModelAdmin (will affect all models, not just your 50)
5 . Monkeypatch you admins (if it's all of your apps models you could just iterate through registered admins and match the ones belonging to your app)
I would personally go with 3. Are there maybe other things these ModelAdmin's have in common? Adding the base class/mixin is a one-off effort and then you could make other changes down the line very easily.
P.S.: If you want to make sure the models aren't deleted, it's probably advisable to make sure their default manager's QuerySet doesn't delete either: https://stackoverflow.com/a/6459797/640759
Related
TL;DR: I don't know how organise my logic domain classes.
I have the model "Application", this model is in the "core" of the App and is the way I "enter" and operate over other models like:
#application = Application.find(params[:application_id])
#application.payment.update_attribute 'active', true
or
unless #application.report.status
or
#application.set_income(params[:income][:new_income])
so the models Payment, Income and Report are basically empty because I initialise the Application model and from there I do things "on cascade" to change the "subordinated" models. But now the Application model has more than forty methods and 600 lines.
I'm doing it right? For instance when I want to add a new Payment I like to do :
payment = Payment.create params
inside the Application model because ActiveRecord "knows" how to handle the foreign keys automatically. I could create the payment inside the Payment model using:
application = Application.find(application_id)
params[:application_id] = application.id
self.create params
but this way, I need to set the Application.id manually and that looks more verbose and not elegant.
So --if I want to reduce my Application model--, should I create modules in APP/lib directory or should I move methods to the other models?
should I create modules in APP/lib directory
Basically, yes, that's what you should do. Although I'd probably make them classes rather than modules. The pattern it sounds like you're after is called "service Objects" (or sometimes "use cases"). What this does is takes the logic from a specific operation you want to perform, and puts it in it's own self-contained class. That class then collaborates with whatever models it needs to. So, your models stay quite small, and your "Service Classes" follow the Single Responsibility Principle. Your controllers then usually call a single "service class" to do what they need to do - so your controllers stay pretty minimal too.
If you google "rails service objects" or similar, you'll find lots of great stuff, but here's some resources to get you started.
Service objects rails casts: https://www.youtube.com/watch?v=uIp6N89PH-c
https://webuild.envato.com/blog/a-case-for-use-cases/
https://blog.engineyard.com/2014/keeping-your-rails-controllers-dry-with-services
http://blog.codeclimate.com/blog/2012/10/17/7-ways-to-decompose-fat-activerecord-models/ (there's one section on service objects there)
Keep in mind, once you do start using service objects, you don't necessarily have to ALWAYS go through your Application model to get to the related ones. A service object might take an application_id and then do eg. #payment = Payment.find_by(application_id: application_id) and so you don't have to fetch the application instance at all and can manipulate the #payment variable directly.
The fact that Rails makes it "easy" and "pretty" to get to related models doesn't necessarily mean you should do it.
I would not worry about long controller and spec files in Rails.
These files tend to get very long and the usual advice of keeping classes and methods short does not necessarily apply for controllers and their specs.
For example, in our production system user_controller.rb is 8500 lines long and the corresponding user_controller_spec.rb is 7000 lines long.
This is the length of our top 10 controllers
1285 app/controllers/*********_controller.rb
1430 app/controllers/***********_controller.rb
1444 app/controllers/****_controller.rb
1950 app/controllers/****_controller.rb
1994 app/controllers/********_controller.rb
2530 app/controllers/***********_controller.rb
2697 app/controllers/*********_controller.rb
2998 app/controllers/*****_controller.rb
3134 app/controllers/application_controller.rb
8737 app/controllers/users_controller.rb
TL;DR: If your app has four models that are all tied to tables in your database (ie. leveraging ActiveRecord and inheriting from ActiveModel::Base), the framework is pretty opinionated toward using model classes.
Abstractions of the service class pattern can be useful in some cases, but give yourself a break. One of the advantages of Rails is that its supposed to remove a lot of the barriers to development, among many things, by making organization decisions for you. Leverage your model classes.
Let's see if this starts an epic developer bickering war.
Also, its ok to create interfaces in your models for related model creation:
class Application < ActiveModel::Base
has_one :payment
def create_payment(attrs)
payment.create(attrs)
end
end
And by ok, i mean that the framework will allow this. But remember, you're already inheriting from ActiveModel::Base which defines many instance methods, including create.
I would recommend, esp. if this is a small project and you're just getting your feet wet, to use well-named rails controllers to read and write objects to the database:
class ApplicationPaymentsController < ActionController::Base
def create
application = Application.find(params[:id])
application.create_payment(payment_params)
end
private
def payment_params
params.require(:payment).permit(:x, :y) - whatever your attr names are.
end
end
The sleekness you're looking for in abstracting foreign keys in creating a relational record is taken care of for you with Rails associations:
http://guides.rubyonrails.org/association_basics.html (good starting point)
http://apidock.com/rails/ActiveRecord/Associations/ClassMethods/has_one (more explicit docs)
That will help you slim down models if that is your goal. Just for clarification, this is one of those things that devs are extremely opinionated on, one way or another, but the truth is that there are code smells (which should be addressed) and then there are folks who arbitrary preach file length maxes. The most important thing in all of this is readable code.
A good litmus test for refactoring working code is put it down for a few weeks, come back to it, and if its confusing then put in some time to make it better (hopefully guided by already written test coverage). Otherwise, enjoy what you do, especially if you're working solo.
everyone. I'm new to refineryCMS( and rails also). I summed up my question in the end of this article in case the problem description is too long.
Here is my question:
How do I use routes( or namespace) to filter backend contents?
For example, I have several departments on my site. They have similar structures, yet the contents are different. I want to manage them separately. Say, I have department ABC and department EFG and department MAIN, I want to manage them through /refinery/ABC and /refinery/EFG and /refinery(/MAIN).
How can I achieve something like this?
Currently I've two ideas, but not knowing how to implement.
First, I may create each department as rails engine and then mount them on the main_app. However, I don't like this solution because it will duplicate many almost identical tables since each department's structure are quite similar. And I'm not familiar with creating engine, worrying about the performance.
Second way I've thought out is to make every Refinery::Pages, resource and custom engine model belongs to certain department. And then I could write a controller to filter all those thing out by specifying which department like I mentioned above "/refinery/:department".
In short, I prefer the second way, though I don't know how to:
make every model(custom engine or Refinery native ones) belongs to department. Especially for Refinery native ones(resource, image, pages)
how to duplicate the admin rendering like refinery's default backend after controller has filtered content I want.
After some search up, I found that there are too many #variables to filter properly. Is there some easier way?
Thanks in advance!
Routes.rb
try put the:
get 'refinery/:dep' => 'refinery#deps'
then in refinery controller your put
def deps
dep = params[:dep]
*some code*
end
I have a bunch of models in a sub-directory that inherit from a model in the models root directory. I want to be able to set a class variable in another model that lists each inherited model class.
i.e
##groups = sub_models.map do { |model| model.class.to_s }
Not sure how to get at this info though...
There is a full answer here. Basically, you can either troll through the files or monkey-patch Class (or ActiveRecord). Those are two ways to go, at least.
Edit: On second thought, Rails won't load your Models until necessary, so while the "files" way seems weak, it's probably your only option (unless you want to do something in your models themselves).
In Rails, in production env this should work
Object.subclasses_of ClassInModelDir
You have to load the files manually If Rails.env.development?
You will not be able to do this unless you preload your descendant models. This is the reason why it is prudent to reengineer your code to use Class#ancestors instead of descendants (also descendants are not a core Ruby feature).
I'm trying to determine the best structure to approach multi level user groups. Thus far I've created one object called "User" which i assumed could potentially be broken into different levels. Or should I simply create different tables for each user group?
Have a look into Single Table Inheritance..
The short version is that you add a type(string) column to your table and subclass all other models that will use that table from User
Eg:
class SuperUser < User
...
end
I assume you are talking about differnt roles for your users. I am currently using RoleRequirement. It gets the job done fairly easily.
http://code.google.com/p/rolerequirement/
As EmFi suggested, single table inheritance is your best bet. You would need to add the type field to the users table in the database and subclass your User model as below:
class Admin < User
# You probably don't need any methods here.
end
but you would also need to create a before filter. Quite similar to the one which makes sure that the user is logged in, it simply checks the class of your user. This should go in your ApplicationController:
def check_admin
current_user.is_a? Admin
end
There you go, Bob's your uncle, you have rudimentary authorisation.
To promote a user to Admin within rails, just change the type field. Of course, in this way, the user can only hold one access level (which is fine for a lot of applications). If you should want a more complex system, acl9 is quite well equipped for the job. I personally make a habit of using it along with authlogic to form quite a powerful system.
I have a simple model called Party with a corresponding table called parties. There's also a controller with all the usual CRUD actions and so on. This model is used in a website and only one admin user is allowed to edit the parties - everyone else is allowed to call GET actions (index, show). Nothing special so far.
Now I need to do the following: The admin would like to choose a single Party at a time for special presentation (the selected Party is showing up on the start page of the application). The most important thing is, that there's only ONE party at time selected.
How would you solve this problem? Boolean Flag in Party model? Save the selection (id of the party) somewhere outside the database? Implement a new model with a has_one relation to Party (seems like overkill to me)?
I hope my explanation is good enough to understand the issue.
A simple "front_page" attribute would suffice or another model like you mentioned, using the has_one relationship would be fine as well.
Using another model would allow you to maintain some more information, like how long should it remain on the front page (expiration date?) or how many times it was featured (assuming a party can be featured twice). It really depends on other requirements for your system.
You also might be able to get away with a simple implementation of the Singleton pattern as well. There's a quick description on the Rails Wiki of making an ActiveRecord object a Singleton (see below): http://wiki.rubyonrails.org/rails/pages/TipsAndTricks
Making a singleton ActiveRecord object
If you have a table with just one
entry, useful for keeping track of a
number sequence for databases without
sequences, you can use the singleton
module included with ruby like so:
require 'singleton'
class Master < ActiveRecord::Base
include Singleton
def initialize(args=nil) super(args) if record = Master.find(:first)
self.attributes = record.attributes end end def next_tracking_number increment!
(:current_tracking_number) current_tracking_number end def
self.next_tracking_number instance.next_tracking_number
end
end
Update:
This is a very poor code example (was copied and pasted from the Rails Wiki, which had no formatting). I would highly recommend the [Ruby Design Patterns] book which tackles many of the GoF design patterns in greater detail (while making them applicable to Ruby applications). But Google should return you some good resources for using the Singleton pattern in Ruby.2
I would go for the boolean flag and create nested singleton resource (promoted), which I would implement in PartiesController itself (set_promoted_party and get_promoted_party actions). For these I would create two new routes:
PUT /parties/promoted/:party_id # to set the promoted party
GET /parties/promoted/:party_id # to get the promoted_party
I would add a second model that had a has_one relationship in order to keep the app RESTful and simple. Also, this way, you can keep a history of special Parties, and track other meaningful information related to the special parties.
Personally I'm very strong on data integrity being enforced by my database so would probably add that extra table and enforce it as a foreign key constraint there.
It can seem like overkill, but is the only* solution that prevents data integrity issues.
Could you maybe add it as a field to the admin table/model - which would be an enforced foreign key to the party table?
*Another solution would be a database trigger that checks no other rows are the selected party but I tend to shy away from such solutions.
Keep it simple. Put a promoted_party.yml file in your config directory that the controllers write to and read from. The contents can be as simple as this:
---
party_id: 123
Done. If you need more integrity or fancier relationships later, implement that later, not now.
For deployments, just make sure the file is symlinked to a shared directory to survive application upgrades.