I'm looking for best practices. Here's the scenario:
Customers can pay for one or more Widgets from a form. So I have a Payments model and a Widgets model. There is no association between them (Payments is associated with Customer). What's the best way to handle this?
In the Payments controller I could do:
def create
#customer = Customer.find(params[:customer_id])
if #customer.payments.create!(params[:payment])
how-many-widgets = params[:payment][:number].to_i
while how-many-widgets > 0
widget = Widgets.new
... update widget ...
widget.save!
how-many-widgets = how-many-widgets - 1
end
end
redirect_to #customer
end
Is this the best way to do this? Or is there some more elegant solution?
If you're saving and changing things, it's a good bet you should be doing this code in a model, rather than a controller. If I were to refactor your code, it would look a little like this:
def create
#customer = Customer.find(params[:customer_id])
if #customer.payments.create!(params[:payment])
params[:payment][:number].times do
Widget.create(params[:widget])
end
end
redirect_to #customer
end
If Widget.create isn't what you're looking for, come up with a custom method that takes the params in, transforms them, and then spits out the correct object. Also if the widgets should be related to either the customer or payments, don't hesitate to relate them -- like, if you look at that code and say, "I also need to pass the current user/customer/payment to the widget," that would be a good hint that the widget should be associated to that model somehow.
Related
I'm new to Rails (I've worked in MVC but not that much) and I'm trying to do things the "right" way but I'm a little confused here.
I have a site navigation with filters Items by different criteria, meaning:
Items.popular
Items.recommended
User.items
Brand.items # by the parent brand
Category.items # by a category
The problem is that I don't know how to deal with this in the controller, where each action does a similar logic for each collection of items (for example, store in session and respond to js)
Either I have an action in ItemsController for every filter (big controller) or I put it in ItemsController BrandsController, CategoriesController (repeated logic), but neither provides a "clean" controller.
But I don't know witch one is better or if I should do something else.
Thanks in advance!
You're asking two separate questions. Items.popular and Items.recommended are best achieved in your Item model as a named scope This abstracts what Xavier recommended into the model. Then in your ItemsController, you'd have something like
def popular
#items = Item.popular
end
def recommended
#items = Item.recommended
end
This isn't functionally different than what Xavier recommended, but to me, it is more understandable. (I always try to write my code for the version of me that will come to it in six months to not wonder what the guy clacking on the keyboard was thinking.)
The second thing you're asking is about nested resources. Assuming your code reads something like:
class User
has_many :items
end
then you can route through a user to that user's items by including
resources :users do
resources :items
end
in your routes.rb file. Repeat for the other nested resources.
The last thing you said is
The problem is that I don't know how to deal with this in the controller, where each action does a similar logic for each collection of items (for example, store in session and respond to js)
If what I've said above doesn't solve this for you (I think it would unless there's a piece you've left out.) this sounds like a case for subclassing. Put the common code in the superclass, do the specific stuff in the subclass and call super.
There's a pretty convenient way to handle this, actually - you just have to be careful and sanitize things, as it involves getting input from the browser pretty close to your database. Basically, in ItemsController, you have a function that looks a lot like this:
def search
#items = Item.where(params[:item_criteria])
end
Scary, no? But effective! For security, I recommend something like:
def search
searchable_attrs = [...] #Possibly load this straight from the model
conditions = params[:item_criteria].keep_if do |k, v|
searchable_attrs.contains? k
end
conditions[:must_be_false] = false
#items = Item.where(conditions)
end
Those first four lines used to be doable with ActiveSupport's Hash#slice method, but that's been deprecated. I assume there's a new version somewhere, since it's so useful, but I'm not sure what it is.
Hope that helps!
I think both answers(#Xaviers and #jxpx777's) is good but should be used in different situations. If your view is exactly the same for popular and recommended items then i think you should use the same action for them both. Especially if this is only a way to filter your index page, and you want a way to filter for both recommended and popular items at the same time. Or maybe popular items belonging to a specific users? However if the views are different then you should use different actions too.
The same applies to the nested resource (user's, brand's and category's items). So a complete index action could look something like this:
# Items controller
before_filter :parent_resource
def index
if #parent
#items = #parent.items
else
#items = Item.scoped
end
if params[:item_criteria]
#items = #items.where(params[:item_criteria])
end
end
private
def parent_resource
#parent = if params[:user_id]
User.find(params[:user_id])
elsif params[:brand_id]
Brand.find(params[:brand_id])
elsif params[:category_id]
Category.find(params[:category_id])
end
end
Scenario: I have a has_many association (Post has many Authors), and I have a nested Post form to accept attributes for Authors.
What I found is that when I call post.update_attributes(params[:post]) where params[:post] is a hash with post and all author attributes to add, there doesn't seem to be a way to ask Rails to only create Authors if certain criteria is met, e.g. the username for the Author already exists. What Rails would do is just failing and rollback update_attributes routine if username has uniqueness validation in the model. If not, then Rails would add a new record Author if one that does not have an id is in the hash.
Now my code for the update action in the Post controller becomes this:
def update
#post = Post.find(params[:id])
# custom code to work around by inspecting the author attributes
# and pre-inserting the association of existing authors into the testrun's author
# collection
params[:post][:authors_attributes].values.each do |author_attribute|
if author_attribute[:id].nil? and author_attribute[:username].present?
existing_author = Author.find_by_username(author_attribute[:username])
if existing_author.present?
author_attribute[:id] = existing_author.id
#testrun.authors << existing_author
end
end
end
if #post.update_attributes(params[:post])
flash[:success] = 'great!'
else
flash[:error] = 'Urgg!'
end
redirect_to ...
end
Are there better ways to handle this that I missed?
EDIT: Thanks for #Robd'Apice who lead me to look into overriding the default authors_attributes= function that accepts_nested_attributes_for inserts into the model on my behalf, I was able to come up with something that is better:
def authors_attributes=(authors_attributes)
authors_attributes.values.each do |author_attributes|
if author_attributes[:id].nil? and author_attributes[:username].present?
author = Radar.find_by_username(radar_attributes[:username])
if author.present?
author_attributes[:id] = author.id
self.authors << author
end
end
end
assign_nested_attributes_for_collection_association(:authors, authors_attributes, mass_assignment_options)
end
But I'm not completely satisfied with it, for one, I'm still mucking the attribute hashes from the caller directly which requires understanding of how the logic works for these hashes (:id set or not set, for instance), and two, I'm calling a function that is not trivial to fit here. It would be nice if there are ways to tell 'accepts_nested_attributes_for' to only create new record when certain condition is not met. The one-to-one association has a :update_only flag that does something similar but this is lacking for one-to-many relationship.
Are there better solutions out there?
This kind of logic probably belongs in your model, not your controller. I'd consider re-writing the author_attributes= method that is created by default for your association.
def authors_attributes=(authors_attributes)
authors_attributes.values.each do |author_attributes|
author_to_update = Author.find_by_id(author_attributes[:id]) || Author.find_by_username(author_attributes[:username]) || self.authors.build
author_to_update.update_attributes(author_attributes)
end
end
I haven't tested that code, but I think that should work.
EDIT: To retain the other functionality of accepts_nested_Attributes_for, you could use super:
def authors_attributes=(authors_attributes)
authors_attributes.each do |key, author_attributes|
authors_attributes[key][:id] = Author.find_by_username(author_attributes[:username]).id if author_attributes[:username] && !author_attributes[:username].present?
end
super(authors_attributes)
end
If that implementation with super doesn't work, you probably have two options: continue with the 'processing' of the attributes hash in the controller (but turn it into a private method of your controller to clean it up a bit), or continue with my first solution by adding in the functionality you've lost from :destroy => true and reject_if with your own code (which wouldn't be too hard to do). I'd probably go with the first option.
I'd suggest using a form object instead of trying to get accepts_nested_attributes to work. I find that form object are often much cleaner and much more flexible. Check out this railscast
I have basic functionality for sending a user to the moon:
#Action in a controller
def outer_space
user = User.find(params[:id])
user.board_rocket_to_the_moon
end
#user model
def board_rocket_to_the_moon
#put on space suit, climb in rocket, etc.
end
Now, I want to add to this by only sending users to the moon if they like to travel.
Is it better to put the if statement in the controller or the model and why?
#option 1: Put an if in the controller
def outer_space
user = User.find(params[:id])
user.board_rocket_to_the_moon if user.likes_to_travel
end
#option 2: Stick the if in the user model
def board_rocket_to_the_moon
if self.likes_to_travel
#put on space suit, climb in rocket, etc.
return "BLAST OFF"
else
return "There is no way THIS dude is getting on THAT ship."
end
end
According to the SRP, I'd stick to option 1.
Controller is the conductor: it's responsible for the logic and it's more readable.
An alternative would be to create a well named method in your model which would handle the logic and trigger the other method if needed.
Don't forget the tests!
Condition in the model will be better.
But here it depends on requirement.
If you need to display whenever the method calls, it would require in the model.
Only from this action call, you require to display message then condition in controller is good.
I have two Models:
Users, and Articles
Every user is able to create an article but can only edit his own Articles?
Can someone provide an example of that? (Model, Controller and View Please?)
Thanks
EDIT
I do not want the whole code. I can get the most of the code using scaffolding. I need the modifications that I have to do to achieve that. My biggest concern is how to allow only the author of an article to edit it. That's what I am asking.
I can't write the full example code out but I can at least point you in the right direction.
You're describing a one to many association between your two models. This guide is the best I've seen in figuring out how to set up those associations in Rails.
Once you've got that in place you can limit access based on ownership of the article quite easily. For something this straight forward you probably wouldn't need a permissions gem but there are some solid ones out there.
I'd protect access in the controllers and in the view. You can simply check the current_user against the article object on the view, and in the controller you can use before filters to protect the article.
If you get further down this path and have more specific questions I'm glad to try and answer them.
Assuming an Article belongs_to :user and you have an authentication setup that gives you a current_user method, you should be able to do something like this in your ArticlesController:
def edit
#article = Article.find(params[:id])
if #article.user == current_user
render :edit
else
flash[:alert] = "You don't have permission to edit this article."
redirect_to some_path
end
end
You would also need something similar for your update method.
I have a rails app that involves users, essays, and rankings. It's pretty straightforward but I'm very new to rails. The part I'm having trouble with right now is the create method for the rankings.
The Essay class has_many :rankings and the Ranking class belongs_to :essay
in the rankings controller I have:
def create
#ranking = #essay.rankings.build(params[:ranking])
flash[:success] = "Ranking created!"
redirect_to root_path
end
but I get the error: undefined method `rankings' for nil:NilClass
I need each ranking to have an essay_id, and I believe build updates this for me.
I thought that rails give me the rankings method because of the relation I set, and why is #essay nil?
Thanks in advance
Build doesn't save. You should be using new and then save. I'd provide you sample code, but you haven't really given us a clear picture of what you have going on. That #essay instance variable is being used before it's defined, and I'm not really sure how your application is determining which essay the ranking belongs to.
You might wanna give Rails Guides a read.
I think this is what you intend to do:
# EssayController#new
def new
#essay = Essay.new(params[:essay])
#ranking = #essay.rankings.build(params[:ranking])
#...
end
Take a look at nested model forms , it should get you in the right direction.