I want to refactor this ruby code
class UtilService
def summer_start
...
end
def summer_end
...
end
def calc(date, charge, quantity, winter_rate, winter_service_charge, summer_rate)
if date < summer_start || date > summer_end
chargeamt = quantity * winter_rate + winter_service_charge
else
chargeamt = quantity * summer_rate
end
chargeamt
end
end
Since charge isn't being used I know I can get rid of that but other than getting rid of that one parameter I can't think of what else I can actually do.
I was also thinking of breaking up 'calc' into different methods
class UtilService
def summer_start
end
def summer_end
end
def calc_summer_rate(date, quantity, summer_rate)
if date > summer_start || date < summer_end
chargeamt = quantity * summer_rate
end
chargeamt
end
def calc_winter_rate(date, quantity, winter_rate, winter_service_charge)
if date < summer_start || date > summer_end
chargeamt = quantity * winter_rate + winter_service_charge
end
chargeamt
end
end
But it doesn't seem like my refactoring makes much sense.
I would be inclined to write something like the following.
rates = { winter: { per_unit: 123, service_charge: 456 },
summer: { per_unit: 135, service_charge: 0 } }
def calc(date, quantity, rates)
rate = summer?(date) ? rates[:summer] : rates[:winter]
quantity * rate[:per_unit] + rate[:service_charge]
end
def summer?(date)
date.between?(summer_start, summer_end)
end
I don't see big refactoring needed, maybe just moving the is summer? logic to another method and removing unnecesary chargeamt variable; something like this:
class UtilService
def summer_start
end
def summer_end
end
def calc(date, quantity, winter_rate, winter_service_charge, summer_rate)
if summer?(date)
quantity * winter_rate + winter_service_charge
else
quantity * summer_rate
end
end
private
def summer?(date)
date > summer_start || date < summer_end
end
end
Related
I'm new to programming in Ruby.
How do I make the output show Revenue and Profit or Loss?
How can I refactor the following code to look neater? I know it's wrong but I have no idea how to take my if profit out of the initialize method.
class Theater
attr_accessor :ticket_price, :number_of_attendees, :revenue, :cost
def initialize
puts "What is your selling price of the ticket?"
#ticket_price = gets.chomp.to_i
puts "How many audience are there?"
#number_of_attendees = gets.chomp.to_i
#revenue = (#number_of_attendees * #ticket_price)
#cost = (#number_of_attendees * 3) + 180
#profit = (#revenue - #cost)
if #profit > 0
puts "Profit made: $#{#profit}"
else
puts "Loss incurred: $#{#profit.abs}"
end
end
end
theater = Theater.new
# theater.profit
# puts "Revenue for the theater is RM#{theater.revenue}."
# I hope to put my Profit/Loss here
#
# puts theater.revenue
Thanks guys.
Do not initialize the object with input from the user, make your object accept the needed values. Make a method to read the needed input and return you new Theater. Last of all put the if in separate method like #report_profit.
Remember constructors are for setting up the initial state of the object, making sure it is in a valid state. The constructor should not have side effects(in your case system input/output). This is something to be aware for all programming languages, not just ruby.
Try this:
class Theatre
COST = { running: 3, fixed: 180 }
attr_accessor :number_of_audience, :ticket_price
def revenue
#number_of_audience * #ticket_price
end
def total_cost
COST[:fixed] + (#number_of_audience * COST[:running])
end
def net
revenue - total_cost
end
def profit?
net > 0
end
end
class TheatreCLI
def initialize
#theatre = Theatre.new
end
def seek_number_of_attendes
print 'Number of audience: '
#theatre.number_of_audience = gets.chomp.to_i
end
def seek_ticket_price
print 'Ticket price: '
#theatre.ticket_price = gets.chomp.to_i
end
def print_revenue
puts "Revenue for the theatre is RM #{#theatre.revenue}."
end
def print_profit
message_prefix = #theatre.profit? ? 'Profit made' : 'Loss incurred'
puts "#{message_prefix} #{#theatre.net.abs}."
end
def self.run
TheatreCLI.new.instance_eval do
seek_ticket_price
seek_number_of_attendes
print_revenue
print_profit
end
end
end
TheatreCLI.run
Notes:
Never use your constructor (initialize method) for anything other than initial setup.
Try to keep all methods under 5 lines.
Always try to keep each class handle a single responsibility; for instance, printing and formatting output is not something the Theatre class needs to care.
Try extracting all hard coded values; eg see the COST hash.
Use apt variables consistent to the domain. Eg: net instead of profit makes the intent clear.
I am creating a simple CC class that can create and update a credit card. To do this, I have created cc_bal{} as an instance object so it can update respect credit cards. The hash is to save and update a person and the amount on their cc. I end up getting an output of just the original amount that was created and not the updated amount
Heres the code:
class CC
def initialize(cc_name, cc_bal = {}, open_cc = false)
#cc_name = cc_name
#cc_bal = cc_bal
#open_cc = open_cc
end
def create(initAmount, person)
if initAmount > 0
#open_cc = true
#cc_bal[:person]=initAmount
puts "congrats #{person} on opening your new #{#cc_name} CC! with $#{#cc_bal[:person]}"
else
puts "sorry not enough funds"
end
end
def update(amount, person)
if #open_cc == true
#cc_bal[:person] + amount
else
puts "sorry no account created, #{person}"
end
puts "#{person} has CC balance of #{#cc_bal[:person]}"
end
end
#chase = Bank.new("JP Morgan Chase")
#wells_fargo = Bank.new("Wells Fargo")
me = Person.new("Shehzan", 500)
friend1 = Person.new("John", 1000)
#chase.open_account(me)
#chase.open_account(friend1)
#wells_fargo.open_account(me)
#wells_fargo.open_account(friend1)
#chase.deposit(me, 200)
#chase.deposit(friend1, 300)
#chase.withdraw(me, 50)
#chase.transfer(me, wells_fargo, 100)
#chase.deposit(me, 5000)
#chase.withdraw(me, 5000)
#puts chase.total_cash_in_bank
#puts wells_fargo.total_cash_in_bank
credit_card = CC.new("Visa")
credit_card.create(10,me)
credit_card.update(50,me)
credit_card.create(20,friend1)
credit_card.update(40,friend1)
Please disregard the function calls that are commented out.
Any idea why the CC's are not updatiing?
if #open_cc == true
#cc_bal[:person] + amount
else
You increase the amount, but you don't set the new value anywhere. It should be
if #open_cc == true
#cc_bal[:person] += amount
else
Note. The code needs some serious refactoring and cleanup.
Forgive me if my question isn't completely clear. I have been awake for way too long and I'm feeling a little brain dead.
I'm doing a Ruby exercise and I can't figure out why my rspec test isn't passing for something I thought would work.
require 'date'
class Product
attr_accessor :photo_src, :promotion, :initial_date
attr_reader :default_photo, :default_price, :current_price
def initialize(name, photo, price)
#name = name
#default_photo = photo
#photo_src = photo
#default_price = price
#current_price = price
#initial_date = Date.today.yday
#promotion = false
end
def price_change(sale_price)
calculator = RedPencilCalculator.new(self)
if promotion
if sale_price > #current_price
calculator.end_promotion!
elsif sale_price < (#default_price - (#default_price * 0.3))
calculator.end_promotion!
end
else
calculator.start_promotion!
end
#current_price = sale_price
end
end
class RedPencilCalculator
attr_accessor :promotion_start, :product
def initialize(product)
#product = product
end
def start_promotion!
if start_promotion?
product.promotion = true
product.photo_src = "redX.png"
#promotion_start = Date.today.yday
end
end
#would need to run daily
def end_promotion?
promotion_duration
if #duration == 30 || #duration == 335
end_promotion!
end
end
def end_promotion!
product.promotion = false
product.photo_src = product.default_photo
product.initial_date = Date.today.yday
end
private
def calculate_range
#min_discount = product.default_price - (product.default_price * 0.05)
#max_discount = product.default_price - (product.default_price * 0.3)
end
def start_promotion?
calculate_range
#max_discount <= product.current_price && product.current_price <= #min_discount && Date.today.yday - product.initial_date >= 30
end
def promotion_duration
current_date = Date.today.yday
#duration = current_date - #promotion_start
end
end
Rspec
This doesn't work:
describe Product do
let(:shoes) { Product.new("shoes", "item.png", 100) }
it 'should change the photo_src and promotion attribute if applicable' do
allow(shoes).to receive(:initial_date) { 100 }
shoes.price_change(75)
expect(shoes.promotion).to eq(true)
expect(shoes.photo_src).to eq("redX.png")
end
end
This does:
describe Product do
let(:shoes) { Product.new("shoes", "item.png", 100) }
let(:calculator) { RedPencilCalculator.new(shoes) }
it 'should change the photo_src and promotion attribute if applicable' do
allow(shoes).to receive(:initial_date) { 100 }
shoes.price_change(75)
calculator.start_promotion!
expect(shoes.promotion).to eq(true)
expect(shoes.photo_src).to eq("redX.png")
end
end
So it seems to me that the start_promotion! method call in the price_change method just isn't working.
I don't have a specific answer to your bug but some suggestions on how to pinpoint the problem.
You're testing too much in one unit test. There's so much that can go wrong it's hard (as you've found) to track down where the bug lies. Even if you work it out now, when something changes down the track (as it inevitably will) it will be at least as difficult as it is now to debug.
Simplify the initializer. It should only set #name, #photo, #price. The other instance variables should be methods (write tests unless they're private).
You suspect RedPencilCalculator#start_promotion! has a bug. Write a test to eliminate that possibility.
With more tests in place, the bug will eventually be cornered and crushed!
Lastly - this is easier said than done - but try writing tests first. It is hard but gets easier and even enjoyable!
ok, I put a puts inside of start_promotion? like this:
p "got past calc range: #{#max_discount.inspect} and #{#min_discount.inspect} and #{product.current_price}"
and got:
"got past calc range: 70.0 and 95.0 and 100"
given that the following line checks that current-price is less than the min-discount...
that's the line you've gotta check/fix to make things work
I have constructed an Event Manager class that performs parsing actions on a CSV file, and produces html letters using erb. It is part of a jumpstart labs tutorial
The program works fine, but I am unable to call multiple methods on an object without the earlier methods interfering with the later methods. As a result, I have opted to create multiple objects to call instance methods on, which seems like a clunky inelegant solution. Is there a better way to do this, where I can create a single new object and call methods on it?
Like so:
eventmg = EventManager.new("event_attendees.csv")
eventmg.print_valid_phone_numbers
eventmg_2 = EventManager.new("event_attendees.csv")
eventmg_2.print_zipcodes
eventmg_3 = EventManager.new("event_attendees.csv")
eventmg_3.time_targeter
eventmg_4 = EventManager.new("event_attendees.csv")
eventmg_4.day_of_week
eventmg_5 = EventManager.new("event_attendees.csv")
eventmg_5.create_thank_you_letters
The complete code is as follows
require 'csv'
require 'sunlight/congress'
require 'erb'
class EventManager
INVALID_PHONE_NUMBER = "0000000000"
Sunlight::Congress.api_key = "e179a6973728c4dd3fb1204283aaccb5"
def initialize(file_name, list_selections = [])
puts "EventManager Initialized."
#file = CSV.open(file_name, {:headers => true,
:header_converters => :symbol} )
#list_selections = list_selections
end
def clean_zipcode(zipcode)
zipcode.to_s.rjust(5,"0")[0..4]
end
def print_zipcodes
puts "Valid Participant Zipcodes"
#file.each do |line|
zipcode = clean_zipcode(line[:zipcode])
puts zipcode
end
end
def clean_phone(phone_number)
converted = phone_number.scan(/\d/).join('').split('')
if converted.count == 10
phone_number
elsif phone_number.to_s.length < 10
INVALID_PHONE_NUMBER
elsif phone_number.to_s.length == 11 && converted[0] == 1
phone_number.shift
phone_number.join('')
elsif phone_number.to_s.length == 11 && converted[0] != 1
INVALID_PHONE_NUMBER
else
phone_number.to_s.length > 11
INVALID_PHONE_NUMBER
end
end
def print_valid_phone_numbers
puts "Valid Participant Phone Numbers"
#file.each do |line|
clean_number = clean_phone(line[:homephone])
puts clean_number
end
end
def time_targeter
busy_times = Array.new(24) {0}
#file.each do |line|
registration = line[:regdate]
prepped_time = DateTime.strptime(registration, "%m/%d/%Y %H:%M")
prepped_time = prepped_time.hour.to_i
# inserts filtered hour into the array 'list_selections'
#list_selections << prepped_time
end
# tallies number of registrations for each hour
i = 0
while i < #list_selections.count
busy_times[#list_selections[i]] += 1
i+=1
end
# delivers a result showing the hour and the number of registrations
puts "Number of Registered Participants by Hour:"
busy_times.each_with_index {|counter, hours| puts "#{hours}\t#{counter}"}
end
def day_of_week
busy_day = Array.new(7) {0}
d_of_w = ["Monday:", "Tuesday:", "Wednesday:", "Thursday:", "Friday:", "Saturday:", "Sunday:"]
#file.each do |line|
registration = line[:regdate]
# you have to reformat date because of parser format
prepped_date = Date.strptime(registration, "%m/%d/%y")
prepped_date = prepped_date.wday
# adds filtered day of week into array 'list selections'
#list_selections << prepped_date
end
i = 0
while i < #list_selections.count
# i is minus one since days of week begin at '1' and arrays begin at '0'
busy_day[#list_selections[i-1]] += 1
i+=1
end
#busy_day.each_with_index {|counter, day| puts "#{day}\t#{counter}"}
prepared = d_of_w.zip(busy_day)
puts "Number of Registered Participants by Day of Week"
prepared.each{|date| puts date.join(" ")}
end
def legislators_by_zipcode(zipcode)
Sunlight::Congress::Legislator.by_zipcode(zipcode)
end
def save_thank_you_letters(id,form_letter)
Dir.mkdir("output") unless Dir.exists?("output")
filename = "output/thanks_#{id}.html"
File.open(filename,'w') do |file|
file.puts form_letter
end
end
def create_thank_you_letters
puts "Thank You Letters Available in Output Folder"
template_letter = File.read "form_letter.erb"
erb_template = ERB.new template_letter
#file.each do |line|
id = line[0]
name = line[:first_name]
zipcode = clean_zipcode(line[:zipcode])
legislators = legislators_by_zipcode(zipcode)
form_letter = erb_template.result(binding)
save_thank_you_letters(id,form_letter)
end
end
end
The reason you're experiencing this problem is because when you apply each to the result of CSV.open you're moving the file pointer each time. When you get to the end of the file with one of your methods, there is nothing for anyone else to read.
An alternative is to read the contents of the file into an instance variable at initialization with readlines. You'll get an array of arrays which you can operate on with each just as easily.
"Is there a better way to do this, where I can create a single new object and call methods on it?"
Probably. If your methods are interfering with one another, it means you're changing state within the manager, instead of working on local variables.
Sometimes, it's the right thing to do (e.g. Array#<<); sometimes not (e.g. Fixnum#+)... Seeing your method names, it probably isn't.
Nail the offenders down and adjust the code accordingly. (I only scanned your code, but those Array#<< calls on an instance variable, in particular, look fishy.)
I have a problem to approach and not sure what the most appropriate method will be to make this work. Here the background to begin:
There are two models I am working with Procedures and Appointments. The Appointments model belongs_to the Procedures model and Procedures model has_many Appointments.
Now on the procedures model there are two key points to focus on, rather, two key columns.
attr_accessible :visits, :occurence
visits is the specific number of times to schedule the Appointment(s).
occurence is the frequency of the visits. An example would be visits: "5", occurence: "weekly"
So when I am submitting my form I would like to write a method that looks at both visits: "x" and occurence: ["weekly", "biweekly", "monthly"] to then create a if or a switch -- php does switch still looking into ruby version -- but I suspect there is an elegant way to write this up.
My current create method looks like this:
def create
#appointment = Appointment.new(params[:appointment])
set_variables
if #appointment.save
flash[:success] = "Appointment scheduled!"
redirect_to patient_path(#current_patient)
else
redirect_to patient_path(#current_patient)
flash[:error] = "Appointment Date and Time cannot be blank, please try again."
end
end
What would be the best way to tackle a) identifying occurence: ["weekly", "biweekly", "monthly"] and then processing visits: "x" based on something similar to:
if #appointment.occurence == "weekly"
(x-1).times do |n|
submit same params but change within params appointment_date: = ((#appointment.appointment_date) + (n+1).week.to_formatted_s(:db)
#appointment.save
end
end
...and so on and so forth using (n+1).month for monthly occurrence (n+2).day and for bi-weekly occurrence(s).
Thank you in advance, hope this clarifies things. Just one item to note, do I need to store in database visits: and occurence:, I suspect not but would like to be certain they are used when hitting the models_controller create function.
Here's a slightly less cluttered solution that should do what you need, though it also assumes that you get rid of the :appointment_date field and change :appointment_time to a DateTime field. For more info on DateTimes check out:
(Stackoverflow will only allow me to post 2 links because I'm a n00b so search "DateTime Ruby" on your favorite search engine for documentation for the Ruby and rails methods for DateTime)
Formatting DateTime to string for views: http://apidock.com/ruby/DateTime/strftime
Intro on using DateTimes in forms: http://guides.rubyonrails.org/form_helpers.html#using-date-and-time-form-helpers
#appointment = Appointment.new(params[:appointment])
set_variables
if #appointment.save
if #procedure.occurence == "WEEKLY"
multiplier = 7
elsif #procedure.occurence == "BIWEEKLY"
multplier = 14
else
multiplier = 30
end
#visits = #procedure.visits - 1
#visits.times do |n|
Appointment.create!(
:procedure_id => #appointment.procedure_id,
:patient_id => #appointment.patient_id,
:appointment_time => (#appointment.appointment_time + (multiplier * n).days),
:attendance => "SCHEDULED"
)
end
else
flash.now[:error] = "There appears to be an error, please try again."
render 'new'
end
Solved for the moment, rather crude--as is my current ruby skill set--but it seems to have done the job.
#appointment = Appointment.new(params[:appointment])
set_variables
#appointment.save
if #procedure.occurence == "BIWEEKLY"
#visits = #procedure.visits - 1
#visits.times do |n|
procedure_id = #appointment.procedure_id
patient_id = #appointment.patient_id
appointment_date = (#appointment.appointment_date +
((n+2)*2).days).to_formatted_s(:db)
appointment_time = #appointment.appointment_time
appointment_notes = #appointment.appointment_notes
attendance = "SCHEDULED"
#scheduled = Appointment.create(procedure_id: procedure_id,
patient_id: patient_id, appointment_date: appointment_date,
appointment_time: appointment_time,
appointment_notes: appointment_notes, attendance: attendance)
end
end
if #procedure.occurence == "WEEKLY"
#visits = #procedure.visits - 1
#visits.times do |n|
procedure_id = #appointment.procedure_id
patient_id = #appointment.patient_id
appointment_date = (#appointment.appointment_date +
(n+1).week).to_formatted_s(:db)
appointment_time = #appointment.appointment_time
appointment_notes = #appointment.appointment_notes
attendance = "SCHEDULED"
#scheduled = Appointment.create(procedure_id: procedure_id,
patient_id: patient_id, appointment_date: appointment_date,
appointment_time: appointment_time,
appointment_notes: appointment_notes, attendance: attendance)
end
end
if #procedure.occurence == "MONTHLY"
#visits = #procedure.visits - 1
#visits.times do |n|
procedure_id = #appointment.procedure_id
patient_id = #appointment.patient_id
appointment_date = (#appointment.appointment_date + (n+1).month).to_formatted_s(:db)
appointment_time = #appointment.appointment_time
appointment_notes = #appointment.appointment_notes
attendance = "SCHEDULED"
#scheduled = Appointment.create(procedure_id: procedure_id,
patient_id: patient_id, appointment_date: appointment_date,
appointment_time: appointment_time,
appointment_notes: appointment_notes, attendance: attendance)
end
end