I've built a RoR app and implemented a simple booking system. The user is able to look for a space and can book it per day or per hour.
Everything works well, but I would now like to make the user able to look for a space depending on its availability.
I want to user to be able to select a start/end date and a start/end time and to show only spaces that don't have any booking included in this period.
I am using pg search at the moment to look for a space by category and location, but I have no idea how to implement a search by date and time, as it uses a different logic.
I've tried to do it by hand by creating an array of bookings for each space so I could compare it with the params, but it sounded very complicated and not clean (and I started being stuck anyway, as making it available for one hour or several hours or several days makes it even more complicated)
Is there a gem that could do this for me? If I have to do it by hand, what's the best way to begin?
Thanks a lot
Just create an instance method available? which tests there are no bookings that overlap the from to range. You can use none? on the relationship.
class Space
has_many :bookings
def available?(from, to)
bookings.where('start_booking <= ? AND end_booking >= ?', to, from).none?
end
end
Taking some inspiration from the answer of SteveTurczyn. The following might give you some inspiration.
class Space < ApplicationRecord
# attributes: id
has_many :bookings
def self.available(period)
bookings = Booking.overlap(period)
where.not(id: bookings.select(:space_id))
end
def available?(period)
if bookings.loaded?
bookings.none? { |booking| booking.overlap?(period) }
else
bookings.overlap(period).none?
end
end
end
class Booking < ApplicationRecord
# attributes: id, space_id, start, end
belongs_to :space
def self.overlap(period)
period = FormatConverters.to_period(period)
# lteq = less than or equal to, gteq = greater than or equal to
# Other methods available on attributes can be found here:
# https://www.rubydoc.info/gems/arel/Arel/Attributes/Attribute
where(arel_table[:start].lteq(period.end).and(arel_table[:end].gteq(period.start)))
end
def overlap?(period)
period = FormatConverters.to_period(period)
self.start <= period.end && self.end >= period.start
end
module FormatConverters
module_function
def to_period(obj)
return obj if obj.respond_to?(:start) && obj.respond_to?(:end)
obj..obj
end
end
end
With the above implemented you can query a single space if it is available during a period:
from = Time.new(2019, 10, 1, 9, 30)
to = Time.new(2019, 10, 5, 17, 30)
period = from..to
space.available?(period) # true/false
You can get all spaces available:
spaces = Space.available(period) # all available spaces during the period
Note that class methods will also be available on the scope chain:
spaces = Space.scope_01.scope_02.available(period)
I've also added the overlap scope and overlap? helper to simplify creating the above helpers.
Since in my version Booking has a start and end attribute (similar to Range) you can also provide it to any methods accepting a period.
booking_01.overlap?(booking_02) # true/false
To retrieve all bookings that that overlap this very moment:
bookings = Booking.overlap(Time.now) # all bookings overlapping the period
Hope this gave you some inspiration. If you'd like to know how the overlap checking works I have to forward you to this question.
Note: This answer assumes that the provided period is valid. A.k.a. start <= end. If you for some reason provide Time.new(2019, 10, 1)..Time.new(2019, 9, 23) the results are going to be skewed.
Related
I'm a complete novice with CRON jobs but I think I have that set up correctly.
Ultimately what I'm trying to do is send an email every day at 8:00 am to users (and a couple others) that have not logged in within the last 3 days, have not received the email, AND are marked as active OR temp as a status.
So from querying the db in console I know that I can do:
first = User.where(status: 'active').or(User.where(status: 'temp'))
second = first.where("last_login_at < ? ", Time.now-3.days)
third = second.where(notified: false)
That's not certainly clean but I was struggling with finding a contained query that grabbed all that data. Is there a cleaner way to do this query?
I believe I have my cron job set up correctly using a runner. I have whenever installed and in my schedule.rb I have:
every 1.day, at: '8:00 am' do
runner 'ReminderMailer.agent_mailer.deliver'
end
So under app > mailer I created ReminderMailer
class ReminderMailer < ApplicationMailer
helper ReminderHelper
def agent_reminder(user)
#user = user
mail(to: email_recipients(user), subject: 'This is your reminder')
end
def email_recipients(agent)
email_address = ''
email_addresses += agent.notification_emails + ',' if agent.notification_emails
email_addresses += agent.manager
email_address += agent.email
end
end
Where I'm actually struggling is where I should put my queries to send to the mailer, which is why I built a ReminderHelper.
module ReminderHelper
def applicable_agents(user)
agent = []
first = User.where(status: 'active').or(User.where(status: 'temp'))
second = first.where("last_login_at < ? ", Time.now-3.days)
third = second.where(notified: false)
agent << third
return agent
end
end
EDIT: So I know I could in theory do a chain of where queries. There's gotta be a better way right?
So what I need help on is: do I have the right structure in place? Is there a cleaner way to query this data in ActiveRecord for the CRON job? Is there a way to test this?
Try combining them together as if understand the conditions correct
Have not logged in within the last 3 days,
Have not received the email
Are marked as active OR temp as a status
User.where("last_login_at < ? ", 3.days.ago).
where(notified: false).
where(status: ['active', temp])
module ReminderHelper
def applicable_agents(user)
User.where("last_login_at < ? ", 3.days.ago).
where(notified: false).
where(status: ['active', temp])
end
end
You don't need to add/ assign them to array. Because this relation is already like an array. You can use .to_a if you need array. If you just want to iterate over them then users.each should work fine.
Update
class User
scope :not_notified, -> { where(notified: false) }
scope :active_or_temp, -> { where(status: ['active', 'temmp']) }
scope :last_login_in, -> (default_days = 3) { where("last_login_at < ?", default_days.days.ago) }
end
and then use
User.not_notified.active_or_temp.last_login_in(3)
Instead of Time.now-3.days it's better to use 3.days.ago because it keeps time zone also in consideration and avoids unnecessary troubles and failing test cases.
Additionally you can create small small scopes and combine them. More read on scopes https://guides.rubyonrails.org/active_record_querying.html
I have a Project model that has_many: Tasks each Task has_many :users, through: :userAssociations so one person can work on a task but in the case of a meeting or any collaboration many users can work on the same task.
Tasks have a column: t.integer "time" which allows users to state in minutes the time the task took.
In the Show method of the Project, I'd like to be able to sum the total time that the project has taken.
If not for the fact that a Task can have many users through the userAssociations model, I think this would be very easy: #project.tasks.sum(:time) but that won't double count the time if multiple users were working on the task.
Since originally posting this question I was able to get it working with this helper:
def project_time_spent
#timeSum = 0;
#tasks.each do |tsk|
#userTask = UserTask.where(task_id: tsk.id);
if #userTask.count(:id) > 1
#timeSum += tsk.time * #userTask.count(:id)
else
#timeSum += tsk.time
end
end
return #timeSum
end
But this doesn't feel very "Railsy". Do any Rails gurus recommend a cleaner approach? Am I missing out on an easy method?
You can do it a little easier than that since a task has many users. I think you can also use inject here.
def project_time_spent
#tasks.inject { |sum, tsk| sum + (tsk.time * tsk.users.count) }
end
You can include an instance method in your Project model:
def time_spent
self.tasks.inject { |sum, tsk| sum + (tsk.time * tsk.users.count) }
end
I wouldn't bother checking for count > 1. The savings getting rid of the multiply are minuscule.
I'm creating an application that creates polls, each poll has many poll pages, and each poll page has many question clusters, what I want to do is that when a question cluster is deleted, search every question clusters from the same page that had a higher position, and diminish 1.
This is what I tried, but it doesn't even runs:
after_destroy :reassign_position
private
def reassign_position
question_clusters = QuestionCluster.where(poll_page_id: self.poll_page_id)
question_clusters.where("position > ?", self.position)
quest_cluster.each do |question_cluster|
question_cluster.position -= 1
end
end
How can I accomplish what I want?
You are not updating the question_cluster's attribute (position). Take a look:
def reassign_position
question_clusters = QuestionCluster.where(poll_page_id: self.poll_page_id)
question_clusters.where("position > ?", self.position)
quest_cluster.each do |question_cluster|
# actually update the question_cluster
question_cluster.update!(position: question_cluster.position - 1) # <========
end
end
I am creating a chart based on account balance. And here is my some of my codes
module AccountsHelper
def products_chart_data
orders_by_day = Account.total_grouped_by_day(3.days.ago)
(3.days.ago.to_date..Date.today).map do |date|
{
created_at: date,
balance: orders_by_day[date].first.try(:total_balance) || 0
}
end
end
end
class Account < ActiveRecord::Base
belongs_to :user
has_many :books
def self.total_grouped_by_day(start)
balances = where(created_at: start.beginning_of_day..Time.zone.now)
balances = balances.group("date(created_at)")
balances = balances.select("created_at, balance as total_balance")
balances.group_by {|o| o.created_at.to_date }
end
end
My problems are:
1) I received an error undefined method `first' when mapping 3.days.ago, but successfully run the code when I change it to 2.days.ago. I understand that it is because I do not have data on 3 days ago as this account is new. My question is, how can I rescue this error, because I could have many other new accounts that do not have data yet, and what could I do to display result for 1 month, or 2 month?
Thanks in advance!
# ⇓⇓⇓⇓⇓⇓⇓⇓⇓⇓⇓
balance: orders_by_day[date].try(:first).try(:total_balance) || 0
try is the method, introduced by rails and defined on Object class, therefore it is defined on NilClass as well.
The implementation is quite straightforward: it checks whether receiver is empty and returns either the result of the call to it, or nil otherwise.
I'm trying to display a count of impressions per day for the last 30 days in the specific users time zone. The trouble is that depending on the time zone, the counts are not always the same, and I'm having trouble reflecting that in a query.
For example, take two impressions that happen at 11:00pm in CDT (-5) on day one, and one impression that happens at 1:00am CDT. If you query using UTC (+0) you'll get all 3 impressions occurring on day two, instead of two the first day and one the second. Both CDT times land on the day two in UTC.
This is what I'm doing now, I know I must be missing something simple here:
start = 30.days.ago
finish = Time.now
# if the users time zone offset is less than 0 we need to make sure
# that we make it all the way to the newest data
if Time.now.in_time_zone(current_user.timezone) < 0
start += 1.day
finish += 1.day
end
(start.to_date...finish.to_date).map do |date|
# get the start of the day in the user's timezone in utc so we can properly
# query the database
day = date.to_time.in_time_zone(current_user.timezone).beginning_of_day.utc
[ (day.to_i * 1000), Impression.total_on(day) ]
end
Impressions model:
class Impression < ActiveRecord::Base
def self.total_on(day)
count(conditions: [ "created_at >= ? AND created_at < ?", day, day + 24.hours ])
end
end
I've been looking at other posts and it seems like I can let the database handle a lot of the heavy lifting for me, but I wasn't successful with using anything like AT TIME ZONE or INTERVAL.
What I have no seems really dirty, I know I must missing something obvious. Any help is appreciated.
Ok, with a little help from this awesome article I think I've figured it out. My problem stemmed from not knowing the difference between the system Ruby time methods and the time zone aware Rails methods. Once I set the correct time zone for the user using an around_filter like this I was able to use the built in Rails methods to simplify the code quite a bit:
# app/controllers/application_controller.rb
class ApplicationController < ActionController::Base
around_filter :set_time_zone
def set_time_zone
if logged_in?
Time.use_zone(current_user.time_zone) { yield }
else
yield
end
end
end
# app/controllers/charts_controller.rb
start = 30.days.ago
finish = Time.current
(start.to_date...finish.to_date).map do |date|
# Rails method that uses Time.zone set in application_controller.rb
# It's then converted to the proper time in utc
time = date.beginning_of_day.utc
[ (time.to_i * 1000), Impression.total_on(time) ]
end
# app/models/impression.rb
class Impression < ActiveRecord::Base
def self.total_on(time)
# time.tomorrow returns the time 24 hours after the instance time. so it stays UTC
count(conditions: [ "created_at >= ? AND created_at < ?", time, time.tomorrow ])
end
end
There might be some more that I can do, but I'm feeling much better about this now.
Presuming the around_filter correctly works and sets the Time.zone in the block, you should be able to refactor your query into this:
class Impression < ActiveRecord::Base
def self.days_ago(n, zone = Time.zone)
Impression.where("created_at >= ?", n.days.ago.in_time_zone(zone))
end
end