Here is my issue. I have two models (Construction and Customer)
class Construction < ApplicationRecord
has_many :works
belongs_to :customer
end
class Customer < ApplicationRecord
has_many :constructions
end
I would like to associate a Customer to a Construction during the creation of a new construction.
To do so I have de following controller's method (which is obviously false)
def create
# #construction = Construction.new(constructions_params) (commented)
#construction = Construction.new(customer: #customer)
#customer = Customer.find(params[:customer_id])
#construction.save!
end
from the params I am able to understand that the construction is not saved because it is not attached to a customer and so cannot be created.
I am new to rails and I have been struggling for hours now..
Hope someone will be able to help me.
thanks a lot
Try to revert the order:
#customer = Customer.find(params[:construction][:customer_id])
#construction = Construction.new(customer: #customer)
#construction.save!
you need to assign #customer instance variable before you use it. Otherwise it's nil and nothing is assigned to the new Construction record.
If you have the customer_id available at the point of form creation I reckon that you can do something like this.
Also given the belongs_to relations with the customer on the construction, you should be able to update the customer_id on the construction.
def create
#construction = Construction.new(construction_params)
if #construction.save
# whatever you want to do on success
else
# Whatever you want to do on failure
end
end
# Given you have construction params
private
def construction_params
params.require(:construction).permit(:all, :the, :construction, :attributes, :customer_id)
end
Related
Everything is working fine but I want to change the code in create action to something like in update action. Right now, in the create action I am looping through all the values and saving them, but want to do it in a single line.
I have a College model.
class College< ActiveRecord::Base
has_many :staffs, dependent: :destroy
accepts_nested_attributes_for :staffs, reject_if: :all_blank, allow_destroy: true
end
And this is my Staff.rb
class Staff < ActiveRecord::Base
belongs_to :college
end
And these are my Staffs controller create and update actions
def create
#college= College.find(params[:college][:id_college_profile]
)
staff_params = params[:college][:staffs_attributes].values
staff_params.each do |staff_param|
#staff = #college.staffs.new
#staff.name = staff_param[:name]
#staff.designation = staff_param[:designation]
#staff.experience = staff_param[:experience]
#staff.specialization = staff_param[:specialization]
#staff.save
end
redirect_to dashboard_path(id: #college.id), notice: "Successfully added Staff."
end
def update
#college= College.find(params[:college][:id_college]
)
#college.update_attributes(staff_parameters)
redirect_to root_path
end
These are strong parameters
def staff_parameters
params.require(:college).permit(:id, staffs_attributes: [:id, :name, :specialization, :experience, :designation, :_destroy])
end
Is there a way to save all of staffs in create action, without looping through all the values, but save all of them with a single line of code as in update action?
I have tried this in the StaffsController create action
def create
#college= College.find(params[:college][:id_college]
)
#staff= #college.staffs.new(staff_parameters)
#staff.save
redirect_to dashboard_path(id: #college.id), notice: "Successfully added Staffs."
end
But it threw this error
unknown attribute 'staffs_attributes' for Staff.
Can someone kindly help me with this issue?
This is a CollegesController so I am assuming the create action also creates the new college?
So in that case your create action should simply be something like:
def create
#college = College.new(staff_parameters)
if #college.save
# succesfully created
else
# there was a validation error
end
end
Note that in general we would use college_parameters because the root element is college and that you not only edit the nested staff, but also possibly attributes from college.
If the college always already exists (because you are doing a find), it is a bit confusing to me what the difference is between create and update and why not always render the edit action in that case?
I have a demo-project show-casing cocoon and nested attributes.
You can do this many ways. The "staff_parameters" method threw an error because you are calling it on class Staff in the create action and on the college class for the update action. Simplest thing to do what you want is to copy the staff parameters method strong parameters and duplicate it. Name this second method create_staff and change the "params.require(:college)" part to "params.require(:staff)" and leave the rest the same. Then in your create action you can do "college.staff(create_staff)". Im on my phone so the formatting isnt good lol i put the code in quotes.
Here is my problem...I am setting up a game where several users can play a game with 10,000 raffle tickets. Every game will have 10,000 raffle tickets and will not start until all 10,000 raffle tickets are sold. That being said, I have two simple classes in my DB, and for every game that goes, I need to initialize the 10,000 unique tickets for a single game relationship. I'm not sure where I'm going wrong here. Any help would be greatly appreciated.
models/game.rb
class Game < ActiveRecord::Base
has_many :tickets
end
models/ticket.rb
class Ticket < ActiveRecord::Base
belongs_to :game
end
controllers/games_controller.rb
class GamesController < ApplicationController
def create
g = Game.new
g.winning_ticket_num = params["winning_ticket_num"]
g.value_per_ticket = params["value_per_ticket"]
g.save
10000.times do
ticket = Ticket.new
ticket.game_id = g.id
ticket.nickname = "null"
ticket.save
end
end
end
controllers/tickets_controller.rb
class TicketsController < ApplicationController
def create
t = Ticket.new
t.nickname = params["nickname"]
t.game_id = params["game_id"]
t.save
end
end
After all the comments exchanged, let's summarize:
class GamesController < ApplicationController
def create
#game = Game.new(params[:game])
10000.times do
#game.tickets.build(nickname: "null")
end
#game.save
end
end
Game.new creates your game, based on the parameters in your view. The "winning_ticket_num" and "value_per_ticket" will be automatically "copied" to your new game object. You must make sure these parameters can be assigned to, either using strong parameters in Rails, or using attr_accessible in Rails < 4.0
The #game.tickets.build creates the 10000 tickets. The game's ID will be automatically assigned when the game is finally saved. Also the tickets themselves will be saved when the parent game is saved
The thing i see that is wrong, If you are using form_for, then the params are params[:game]
class GamesController < ApplicationController
def create
g = Game.new
g.winning_ticket_num = params[:game]["winning_ticket_num"]
g.value_per_ticket = params[:game]["value_per_ticket"]
g.save
10000.times do
ticket = Ticket.new
ticket.game_id = g.id
ticket.nickname = "null"
ticket.save
end
end
end
So adding params[:game] will get the values
Don't set the IDs yourself, use ActiveRecord associations. Note that tickets.create will save the Ticket object to the database when it is created (which seems what you wanted to do above).
def create
#g = Game.new
#g.winning_ticket_num = params["winning_ticket_num"]
#g.value_per_ticket = params["value_per_ticket"]
#g.save
10000.times do
#g.tickets.create(nickname => "null")
end
end
EDIT: syntax error, the = changed to =>. Also remove the ticket. part. Sorry, this is what happens without tests.
I have a user-to-user messaging system. I'm trying to pass an array of user ids to a ConversationUser (join table) model which would then create multiple conversation_users from each individual user.id. The two fields in ConversationUser are conversation_id and user_id. I'm able to initialize a single conversation user because the new conversation_id is being passed along to the model, but for some reason, the hash of user ids is not getting to my model. I'm getting a Validation failed: User can't be blank
My conversation/new view for capturing the user_ids:
<%= check_box_tag "conversation_user[recipient][]", user.id %> <%= user.name %><br />
I know this is working because part of my params that I'm receiving back are:
"conversation_user"=>{"recipient"=>["9", "10"]}
The essentials of my Rails 4 controller & strong params:
class ConversationsController < ApplicationController
def new
#user = User.find(params[:user_id])
#conversation = #user.conversation_users.build
#conversation.build_conversation.messages.build
end
def create
#conv = Conversation.create!
#conversation = #conv.conversation_users.create!(conversation_user_params)
end
def conversation_user_params
params.require(:conversation_user).permit(recipient: [])
end
The essentials of my ConversationUser model:
class ConversationUser < ActiveRecord::Base
attr_accessor :recipient
before_create :acquire_conversation
validates :user_id, :conversation_id, presence: true
def acquire_conversation
unless recipient.blank?
recipient.each do |u|
ConversationUser.create(user_id: u, conversation: conversation)
end
end
end
end
I think the problem is somewhere in my controller's conversation_user_params. But it also might be in the model's before_create method. I've been trying to fix this problem for a day now, with lots of debugging with no success. If anyone can be of assistance, I thank you in advance.
The problem is in the model. before_create callback is called before creating a ConversationUser. Let's name this created ConversationUser as CURRENT. So, before creating the CURRENT ConversationUser you loop through recipient ids and create a ConversationUser for each of them. The ConversationUsers that you are creating here are not CURRENT ConversationUser. CURRENT ConversationUser is saved after the callback is executed (after you create other ConversationUsers). But in this case CURRENT ConversationUser doesn't know wich User it belongs to, because you pass user_id parameter to ConversationUsers that you create in before_create callback, but you do not pass it to CURRENT ConversationUser when it is created (when original create! method is executed).
To solve this problem you can override original create! method or not use it at all for creating ConversationUsers by recipient ids. Add a new method to your Conversation model (for example create_conversation_users):
Solution
In the controller:
def create
#conv = Conversation.create!
#conversation = #conv.create_conversation_users!(conversation_user_params[:recipient])
end
In the model:
class Conversation
def create_conversation_users!(recipient_ids)
return if recipient_ids.blank?
recipient_ids.each do |recipient_id|
conversation_users.create!(user_id: recipient_id, conversation: self)
end
end
end
You should also update ConversationUser model:
class ConversationUser < ActiveRecord::Base
validates :user_id, :conversation_id, presence: true
end
The error is in the ConversationUser. before_create callbacks are ran before a record is created in the database BUT after validations are ran. To solve your issue, there's a few things you can do. One of them was answered by Chumakoff. Here's another option you can use.
Remove all the code inside ConversationUser and change conversation_user_params to
def conversation_user_params
params[:conversation_user][recipient].map do |recipient|
{ user_id: recipient }
end
end
What happens is you're passing an array of { user_id: 1 } to create! which is the same as calling multiple create!({ user_id: 1 }).
In my Rails app I have users who can have many payments.
class User < ActiveRecord::Base
has_many :invoices
has_many :payments
def year_ranges
...
end
def quarter_ranges
...
end
def month_ranges
...
end
def revenue_between(range, kind)
payments.sum_within_range(range, kind)
end
end
class Invoice < ActiveRecord::Base
belongs_to :user
has_many :items
has_many :payments
...
end
class Payment < ActiveRecord::Base
belongs_to :user
belongs_to :invoice
def net_amount
invoice.subtotal * percent_of_invoice_total / 100
end
def taxable_amount
invoice.total_tax * percent_of_invoice_total / 100
end
def gross_amount
invoice.total * percent_of_invoice_total / 100
end
def self.chart_data(ranges, unit)
ranges.map do |r| {
:range => range_label(r, unit),
:gross_revenue => sum_within_range(r, :gross),
:taxable_revenue => sum_within_range(r, :taxable),
:net_revenue => sum_within_range(r, :net) }
end
end
def self.sum_within_range(range, kind)
#sum ||= includes(:invoice => :items)
#sum.select { |x| range.cover? x.date }.sum(&:"#{kind}_amount")
end
end
In my dashboard view I am listing the total payments for the ranges depending on the GET parameter that the user picked. The user can pick either years, quarters, or months.
class DashboardController < ApplicationController
def show
if %w[year quarter month].include?(params[:by])
#unit = params[:by]
else
#unit = 'year'
end
#ranges = #user.send("#{#unit}_ranges")
#paginated_ranges = #ranges.paginate(:page => params[:page], :per_page => 10)
#title = "All your payments"
end
end
The use of the instance variable (#sum) greatly reduced the number of SQL queries here because the database won't get hit for the same queries over and over again.
The problem is, however, that when a user creates, deletes or changes one of his payments, this is not reflected in the #sum instance variable. So how can I reset it? Or is there a better solution to this?
Thanks for any help.
This is incidental to your question, but don't use #select with a block.
What you're doing is selecting all payments, and then filtering the relation as an array. Use Arel to overcome this :
scope :within_range, ->(range){ where date: range }
This will build an SQL BETWEEN statement. Using #sum on the resulting relation will build an SQL SUM() statement, which is probably more efficient than loading all the records.
Instead of storing the association as an instance variable of the Class Payment, store it as an instance variable of a user (I know it sounds confusing, I have tried to explain below)
class User < ActiveRecord::Base
has_many :payments
def revenue_between(range)
#payments_with_invoices ||= payments.includes(:invoice => :items).all
# #payments_with_invoices is an array now so cannot use Payment's class method on it
#payments_with_invoices.select { |x| range.cover? x.date }.sum(&:total)
end
end
When you defined #sum in a class method (class methods are denoted by self.) it became an instance variable of Class Payment. That means you can potentially access it as Payment.sum. So this has nothing to do with a particular user and his/her payments. #sum is now an attribute of the class Payment and Rails would cache it the same way it caches the method definitions of a class.
Once #sum is initialized, it will stay the same, as you noticed, even after user creates new payment or if a different user logs in for that matter! It will change when the app is restarted.
However, if you define #payments_with_invoiceslike I show above, it becomes an attribute of a particular instance of User or in other words instance level instance variable. That means you can potentially access it as some_user.payments_with_invoices. Since an app can have many users these are not persisted in Rails memory across requests. So whenever the user instance changes its attributes are loaded again.
So if the user creates more payments the #payments_with_invoices variable would be refreshed since the user instance is re-initialized.
Maybe you could do it with observers:
# payment.rb
def self.cached_sum(force=false)
if #sum.blank? || force
#sum = includes(:invoice => :items)
end
#sum
end
def self.sum_within_range(range)
#sum = cached_sum
#sum.select { |x| range.cover? x.date }.sum(&total)
end
#payment_observer.rb
class PaymentObserver < ActiveRecord::Observer
# force #sum updating
def after_save(comment)
Payment.cached_sum(true)
end
def after_destroy(comment)
Payment.cached_sum(true)
end
end
You could find more about observers at http://apidock.com/rails/v3.2.13/ActiveRecord/Observer
Well your #sum is basically a cache of the values you need. Like any cache, you need to invalidate it if something happens to the values involved.
You could use after_save or after_create filters to call a function which sets #sum = nil. It may also be useful to also save the range your cache is covering and decide the invalidation by the date of the new or changed payment.
class Payment < ActiveRecord::Base
belongs_to :user
after_save :invalidate_cache
def self.sum_within_range(range)
#cached_range = range
#sum ||= includes(:invoice => :items)
#sum.select { |x| range.cover? x.date }.sum(&total)
end
def self.invalidate_cache
#sum = nil if #cached_range.includes?(payment_date)
end
Let's say I have a simple model:
class Subscription < ActiveRecord::Base
attr_accessor :subscribed
def subscribed
#subscribed = Subscription.where(task_id, user_id)
!#subscribed.empty?
end
end
I'd like to make sure I can take a #subscription instance and call #subscription.subscribed - at the moment it can't find the method.
I think you are doing something like:
#subscription = Subscription.where(task_id, user_id)
#subscription.subscribed
instead of something like this:
#subscription = Subscription.where(task_id, user_id).first
#subscription.subscribed
It's just a guess.
I believe the problem is your where call. Try this:
class Subscription < ActiveRecord::Base
belongs_to :task
belongs_to :user
attr_accessor :subscribed
def subscribed?
#subscribed ||= !Subscription.where(:task_id => task.id, :user_id => user.id).empty?
end
end
If I'm correctly understanding what you're trying to do I think that should work.
But it still doesn't make a lot of sense to me to have this method on the Subscription model. If a subscription exists wouldn't that mean that the user is subscribed automatically. Was this meant to be a class method mabye? I'd think user.subscribed_to? issue or Issue.has_subscriber? user would be a better place to handle this.
If I understand your problem, you can do:
class Subscription < ActiveRecord::Base
attr_accessor :subscribed
def subscribed?
#subscribed = Subscription.where(task_id, user_id)
!#subscribed.empty?
end
end
and you can do (a.i):
s = Subscription.first
s.subscribed? # true or false
s.subscribed # the object (#subscribed)
From your error in the comments, your object called #subscription is not pointing to an instance of Subscription but instead a relation.
Probably you did something like
#subscription = Subscription.where(... some condition ...)
which returns a relation, which you can access as an array. So call .first to get the first element out of it. Or use Subscription.find.
Hope this helps.