Rails 4 Create Related Object After Save - ruby-on-rails

I have two models with the [fields]:
Order [:date]
Delivery Slot [:day]
Order belongs_to :delivery_slot
When an order is created, I want a delivery slot to be created with the :day set to the order :date.
So far I have created a new method create_delivery_slots in the Order controller that creates a Delivery Slot when the Order is created, but where I am stumped is, how do I get the Order :date in the Delivery Slot :day field?
#Create delivery slots if they dont already exist
def create_delivery_slots
existingslots = []
existingslots = DeliverySlot.all.select {|slot| slot.day == #order.date}
if existingslots.empty?
slot = DeliverySlot.new(:day => #order.date)
slot.save!
end
I have tried multiple approaches, but no luck. My gut tells me its something to do with strong parameters but I can't figure it out...

I'm not sure exactly of how you're set up but you'll probably want something like this:
class Order < ActiveRecord::Base
has_a :delivery_slot
after_create => :create_delivery_slots
.
#other code stuffs
.
.
private
def create_delivery_slots
existingslots = []
existingslots = DeliverySlot.all.select {|slot| slot.day == self.date}
if existingslots.empty?
slot = DeliverySlot.new(:day => self.date)
slot.save!
end
end
end
That's untested but it should be basically what you need.

Related

Rails controller variable mess

I have a controller that I feel has too many instance variables.
The controller is pulling data from various places and it feels really sloppy.
I have watched some Sandi Metz talks, read books, and other research, and I want to have good practice but I just don't know what to do here.
This method is pulling all the data and sending it to my view and I am able to get it to work, I just know this isn't a good way to go about it and I am hoping someone can point me to some code samples, documentation, videos, or help me understand how to implement a better style.
I have searched on SO and Google but I mostly find people saying to send a hash or JSON to the view, and I want to know if that is ideal before I start on that.
The Client, Project, Person, Role controllers and models have really similar code and I am working on refactoring it to be more DRY.
For example the Client, Project, Person, and Role financial controllers have almost the exact same controller index code as this. :(
I would be happy to add more code if that would help!
This is the project_financials_controller#index
It's pretty much taking in the data from the view and pulling a bunch of data from the database and sending it to a view. I'm currently using only the index method because it was only supposed to be a 'view' but now we can add filters such as time, different clients, etc so I think I need to break it out somehow.
I do have a financial_reports_nav model that this is calling that I could maybe use more, Or even make a financial_reports_controller that pulls the data from the appropriate model and I wont even need the 4 different controllers...
I am totally open to any input/criticism!
def index
# CPPR = Client, Project, Person, Role
#financial_type = 'project'
#financial_params = params
# This pulls the timeframe from the view and figures out the dates requested. (eg. "Last Week")
#timeframe = Financial.time_frame(#financial_params[:timeframe], current_company.timezone, params[:start_date], params[:end_date])
# This grabs all the data required to recall this financial report view at a later time
#financial_nav = FinancialReportNav.set_financial_type(#current_user.id,#financial_type, #start_date, #end_date)
# Grab all active and inactive people for client
#people = Person.active.all
#deleted_people = Person.inactive.all
# This sends over all the info needed to generate the financial reports
#project_financial_populate = Financial.new(#financial_params, #financial_type).populate_project_financials(current_company.default_hourly_cost, current_company.billing_rate, #timeframe[:start_date],#timeframe[:end_date])
# This just pulls all the data from the database that the #project_financial_populate just populated (Can't we just use that??)
#financial_rows = ProjectFinancial.all.map { |p| [ p.project_id, p.billable_hours, p.revenue,p.real_rate, p.hourly_expense, p.labor_expense_total, p.salary_expense, p.gross_profit, p.profit_margin, p.missing_hourly_expense, p.missing_billable_rate ] }
# Using the same view for CPPR's
# Clients has an items count, so we just stuff everything into the first array slot
#items = [1]
# If these are not null then they show an option to change the financial filter type.
#filter_by_client = Client.find_by('id = ?', #financial_params[:filter_by_client])
#filter_by_project = Project.find_by('id = ?', #financial_params[:filter_by_project])
#filter_by_person = Person.find_by('id = ?', #financial_params[:filter_by_person])
#filter_by_role = PersonRole.find_by('id = ?', #financial_params[:filter_by_role])
# This pulls a list of CPPR's that have tracked time in the requested timeframe
#project_list = Financial.project_list(#timeframe[:start_date], #timeframe[:end_date])
#client_list = Financial.client_list(#timeframe[:start_date], #timeframe[:end_date])
#people_list = Financial.people_list(#timeframe[:start_date], #timeframe[:end_date])
end
I always tend to refactor code to be DRY whenever I noticed I have at least 3 instances of duplicate code, but I needed to future-proof the new code to be flexible enough for possible future changes; all of this considered however time permits.
Given your already current code and having told my preferences, this is what I would do:
Model Inheritance
Controller Inheritance
Shared template
Routes
config/routes.rb
resources :client_financial
resources :project_financial
resources :person_financial
resources :role_financial
Models
app/models/financial_record.rb
class FinancialRecord < ActiveRecord::Base # or ApplicationRecord if > Rails 5
self.abstract_class = true
# your shared "financials" model logic here
end
app/models/client_financial.rb
class ClientFinancial < FinancialRecord
# override "financials" methods here if necessary
# or, add new model specific methods / implementation
end
app/models/project_financial.rb
class ProjectFinancial < FinancialRecord
# override "financials" methods here if necessary
# or, add new model specific methods / implementation
end
app/models/person_financial.rb
class PersonFinancial < FinancialRecord
# override "financials" methods here if necessary
# or, add new model specific methods / implementation
end
app/models/role_financial.rb
class RoleFinancial < FinancialRecord
# override "financials" methods here if necessary
# or, add new model specific methods / implementation
end
Controllers
app/controllers/financial_controller.rb
class FinancialController < ApplicationController
before_action :set_instance_variables, only: :index
protected
def set_instance_variables
# strips the last "Controller" substring and change to underscore: i.e. ProjectFinancialsController becomes project_financials
#financial_type = controller_name[0..(-'Controller'.length - 1)].underscore
# get the corresponding Model class
model = #financial_type.camelcase.constantize
# get the correspond Financial Model class
financial_model = "#{#financial_type.camelcase}Financial".constantize
#financial_params = params
#timeframe = Financial.time_frame(#financial_params[:timeframe], current_company.timezone, params[:start_date], params[:end_date])
# I dont know where you set #start_date and #end_date
#financial_nav = FinancialReportNav.set_financial_type(#current_user.id,#financial_type, #start_date, #end_date)
# renamed (or you can set this instance variable name dynamically)
#records = model.active.all
# renamed (or you can set this instance variable name dynamically)
#deleted_records = model.inactive.all
#financial_populate = Financial.new(#financial_params, #financial_type).populate_project_financials(current_company.default_hourly_cost, current_company.billing_rate, #timeframe[:start_date],#timeframe[:end_date])
#financial_rows = financial_model.all.map { |p| [ p.project_id, p.billable_hours, p.revenue,p.real_rate, p.hourly_expense, p.labor_expense_total, p.salary_expense, p.gross_profit, p.profit_margin, p.missing_hourly_expense, p.missing_billable_rate ] }
#items = [1]
#filter_by_client = Client.find_by('id = ?', #financial_params[:filter_by_client])
#filter_by_project = Project.find_by('id = ?', #financial_params[:filter_by_project])
#filter_by_person = Person.find_by('id = ?', #financial_params[:filter_by_person])
#filter_by_role = PersonRole.find_by('id = ?', #financial_params[:filter_by_role])
#project_list = Financial.project_list(#timeframe[:start_date], #timeframe[:end_date])
#client_list = Financial.client_list(#timeframe[:start_date], #timeframe[:end_date])
#people_list = Financial.people_list(#timeframe[:start_date], #timeframe[:end_date])
end
end
app/controllers/client_financials_controller.rb
class ClientFinancialsController < FinancialController
def index
render template: 'financials/index'
end
end
app/controllers/project_financials_controller.rb
class ProjectFinancialsController < FinancialController
def index
render template: 'financials/index'
end
end
app/controllers/person_financials_controller.rb
class ProjectFinancialsController < FinancialController
def index
render template: 'financials/index'
end
end
app/controllers/role_financials_controller.rb
class ProjectFinancialsController < FinancialController
def index
render template: 'financials/index'
end
end
Views
app/views/financials/index.html.erb
<!-- YOUR SHARED "FINANCIALS" INDEX HTML HERE -->
P.S. This is just a simple refactor. Without knowing the fuller scope of the project, and future plans, I'll just do this one. Having said this, I would consider using "polymorpic" associations, and then just have one routes endpoint (i.e. resources :financials) and then just pass in a params filter like: params[:financial_type] which directly already map the financial_type polymorphic column name.

How do I define a static value for a parameter of a new class?

I created a model for a thing called a Lesson that has :content and a :user_id. For early builds of this app, I want the content to be changing, based on my entry, and for the user_id to always = 1 so that it's clean in the DB and there's not a nil value.
How do I go about this?
In my lessons_controller.rb I have this:
def create
#lesson = Lesson.new(params[:lesson])
if #lesson.save
... do something
else
... do something else
I'm guessing this would be the best place to define that the user_id = 1 but how should I go about that?
You can just set #lesson.user_id = 1 in the line after you create it with new, and before you save it.
Another way to do it would be to set a hook in the lesson model -
before_validation :on => :create do |lesson|
lesson.user_id = 1
end

In Rails, what is the best way to update a record or create a new one if it doesn't exist?

I have a create statement for some models, but it’s creating a record within a join table regardless of whether the record already exists.
Here is what my code looks like:
#user = User.find(current_user)
#event = Event.find(params[:id])
for interest in #event.interests
#user.choices.create(:interest => interest, :score => 4)
end
The problem is that it creates records no matter what. I would like it to create a record only if no record already exists; if a record does exist, I would like it to take the attribute of the found record and add or subtract 1.
I’ve been looking around have seen something called find_or_create_by. What does this do when it finds a record? I would like it to take the current :score attribute and add 1.
Is it possible to find or create by id? I’m not sure what attribute I would find by, since the model I’m looking at is a join model which only has id foreign keys and the score attribute.
I tried
#user.choices.find_or_create_by_user(:user => #user.id, :interest => interest, :score => 4)
but got
undefined method find_by_user
What should I do?
my_class = ClassName.find_or_initialize_by_name(name)
my_class.update_attributes({
:street_address => self.street_address,
:city_name => self.city_name,
:zip_code => self.zip_code
})
Assuming that the Choice model has a user_id (to associate with a user) and an interest_id (to associate with an interest), something like this should do the trick:
#user = User.find(current_user)
#event = Event.find(params[:id])
#event.interests.each do |interest|
choice = #user.choices.find_or_initialize_by_interest_id(interest.id) do |c|
c.score = 0 # Or whatever you want the initial value to be - 1
end
choice.score += 1
choice.save!
end
Some notes:
You don't need to include the user_id column in the find_or_*_by_*, as you've already instructed Rails to only fetch choices belonging to #user.
I'm using find_or_initialize_by_*, which is essentially the same as find_or_create_by_*, with the one key difference being that initialize doesn't actually create the record. This would be similar to Model.new as opposed to Model.create.
The block that sets c.score = 0 is only executed if the record does not exist.
choice.score += 1 will update the score value for the record, regardless if it exists or not. Hence, the default score c.score = 0 should be the initial value minus one.
Finally, choice.save! will either update the record (if it already existed) or create the initiated record (if it didn't).
find_or_create_by_user_id sounds better
Also, in Rails 3 you can do:
#user.choices.where(:user => #user.id, :interest => interest, :score => 4).first_or_create
If you're using rails 4 I don't think it creates the finder methods like it used to, so find_or_create_by_user isn't created for you. Instead you'd do it like this:
#user = User.find(current_user)
#event = Event.find(params[:id])
for interest in #event.interests
#user.choices.find_or_create_by(:interest => interest) do |c|
c.score ||= 0
c.score += 1
end
end
In Rails 4
You can use find_or_create_by to get an object(if not exist,it will create), then use update to save or update the record, the update method will persist record if it is not exist, otherwise update record.
For example
#edu = current_user.member_edu_basics.find_or_create_by(params.require(:member).permit(:school))
if #edu.update(params.require(:member).permit(:school, :majoy, :started, :ended))

Rails Dynamic Range Validations

How can I validate a number within a range dynamically using existing data?
For example - I have certain discounts on bulk ordering of products. If a customer buys 10-50 units they get X off and if they order 51-200 units Y off.
How can I validate this so that users can't put in quantity discounts over the same range?
I don't quite understand your question but I'm sure a custom validation would be one way to solve whatever you are trying to achieve. Simply add a validate method in your model like so:
def validate
self.errors.add(:amount, "is out of range") unless self.amount_in_allowed_range
end
private
def amount_in_allowed_range
# logic to return true or false
end
If I understand your question correctly then you are trying to avoid the creation of a discount range that overlaps an already existing one. The following code should do this for you
class QtyDiscount < ActiveRecord::Base
def validate
self.errors.add(:amount, "overlaps an existing range")
unless self.amount_in_allowed_range
end
def amount_in_allowed_range
# Check for overlapping ranges where our record either
# - overlaps the start of another
# - or overlaps the end of another
conditions = "
id != :id AND (
( min_value BETWEEN :min_value AND :max_value) OR
( max_value BETWEEN :min_value AND :max_value))"
puts "Conditions #{conditions}"
overlaps = QtyDiscount.find(:all, :conditions =>
[ conditions, { :id => self.id.nil? ? 0 : self.id,
:min_value => self.min_value,
:max_value => self.max_value} ])
overlaps.size == 0
end
end
EDITED
Removed an extraneous condition and added some checking for self.id to ensure we are not getting a false negative from our own record

How do I populate a table in rails from a fixture?

Quick summary:
I have a Rails app that is a personal checklist / to-do list. Basically, you can log in and manage your to-do list.
My Question:
When a user creates a new account, I want to populate their checklist with 20-30 default to-do items. I know I could say:
wash_the_car = ChecklistItem.new
wash_the_car.name = 'Wash and wax the Ford F650.'
wash_the_car.user = #new_user
wash_the_car.save!
...repeat 20 times...
However, I have 20 ChecklistItem rows to populate, so that would be 60 lines of very damp (aka not DRY) code. There's gotta be a better way.
So I want to use seed the ChecklistItems table from a YAML file when the account is created. The YAML file can have all of my ChecklistItem objects to be populated. When a new user is created -- bam! -- the preset to-do items are in their list.
How do I do this?
Thanks!
(PS: For those of you wondering WHY I am doing this: I am making a client login for my web design company. I have a set of 20 steps (first meeting, design, validate, test, etc.) that I go through with each web client. These 20 steps are the 20 checklist items that I want to populate for each new client. However, while everyone starts with the same 20 items, I normally customize the steps I'll take based on the project (and hence my vanilla to-do list implementation and desire to populate the rows programatically). If you have questions, I can explain further.
Just write a function:
def add_data(data, user)
wash_the_car = ChecklistItem.new
wash_the_car.name = data
wash_the_car.user = user
wash_the_car.save!
end
add_data('Wash and wax the Ford F650.', #user)
I agree with the other answerers suggesting you just do it in code. But it doesn't have to be as verbose as suggested. It's already a one liner if you want it to be:
#new_user.checklist_items.create! :name => 'Wash and wax the Ford F650.'
Throw that in a loop of items that you read from a file, or store in your class, or wherever:
class ChecklistItem < AR::Base
DEFAULTS = ['do one thing', 'do another']
...
end
class User < AR::Base
after_create :create_default_checklist_items
protected
def create_default_checklist_items
ChecklistItem::DEFAULTS.each do |x|
#new_user.checklist_items.create! :name => x
end
end
end
or if your items increase in complexity, replace the array of strings with an array of hashes...
# ChecklistItem...
DEFAULTS = [
{ :name => 'do one thing', :other_thing => 'asdf' },
{ :name => 'do another', :other_thing => 'jkl' },
]
# User.rb in after_create hook:
ChecklistItem::DEFAULTS.each do |x|
#new_user.checklist_items.create! x
end
But I'm not really suggesting you throw all the defaults in a constant inside ChecklistItem. I just described it that way so that you could see the structure of the Ruby object. Instead, throw them in a YAML file that you read in once and cache:
class ChecklistItem < AR::Base
def self.defaults
##defaults ||= YAML.read ...
end
end
Or if you wand administrators to be able to manage the default options on the fly, put them in the database:
class ChecklistItem < AR::Base
named_scope :defaults, :conditions => { :is_default => true }
end
# User.rb in after_create hook:
ChecklistItem.defaults.each do |x|
#new_user.checklist_items.create! :name => x.name
end
Lots of options.
A Rails Fixture is used to populate test-data for unit tests ; Dont think it's meant to be used in the scenario you mentioned.
I'd say just Extract a new method add_checklist_item and be done with it.
def on_user_create
add_checklist_item 'Wash and wax the Ford F650.', #user
# 19 more invocations to go
end
If you want more flexibility
def on_user_create( new_user_template_filename )
#read each line from file and call add_checklist_item
end
The file can be a simple text file where each line corresponds to a task description like "Wash and wax the Ford F650.". Should be pretty easy to write in Ruby,

Resources