As a mum with a busy household to run, it is important to me that I stay on top of things lest there will be chaos and then my brain will just go into meltdown. I love being organised and making lists and so for this project, I decided to build something that can help me keep track of all the voucher or discount codes that I find or get from various places - leaflets, newspapers, shop promos, you get the gist!
Although very basic, it does a good job of storing the shop name for which the voucher can be used as well as other key information such as the actual discount code, expiry date and how much savings you can get. I would definitely spend more time refining it and making it look pretty but for now, I’m still proud of what I have built.
It helped solidify my understanding of the MVC structure, CRUD (Create, Read, Update and Delete), ActiveRecord Associations and RESTful Routes.
The Model-View-Controller framework is a popular way of structuring the program’s files and maintaining separation of concerns. I think understanding this concept considerably helped to make the building process feel a lot more manageable.
- Model - contains the underlying logical structure of the application and where the high-level classes are defined.
- View - contains the information about how your pages should be rendered i.e. user-interface
- Controller - contains the information about the processes that connect the model and the view (including handling input)
Sinatra allows us to bring these together with CRUD actions to build this simple Voucher Tracker app.
- Create - in Sinatra by building a route to render a form for creating a new instance of a model. In my app, an example would be the Sign Up form to create new instances of users and the Submit a new code form that creates new instances of vouchers.
- Read - I enabled my users to read all the instances of a class via the “vouchers/index” erb page or only a specific instance of it via the “show” erb page.
- Update - the users can edit the details of the voucher code. I enabled this by rendering an update form and a controller action to catch the post request sent by that form.
- Delete - is a delete button that is included in the “show” erb page.
**Other things I learned: **
Apart from implementing the above actions, I had a lot of practice in implementing associations between classes or models via ActiveRecord.
For my app, a User model can have many Vouchers and so this was implemented simply by adding has_many :vouchers within the User model and belongs_to :user within the Voucher model.
class User < ActiveRecord::Base
has_secure_password
validates :email, presence: true, uniqueness: true
validates_presence_of :password
has_many :vouchers
end
class Voucher < ActiveRecord::Base
belongs_to :user
belongs_to :store
end
At the same time, to enable the association to be reflected on database, I needed to create a column for the user_id in the vouchers table. I implemented this by adding a belongs_to reference as below:
class CreateVoucher < ActiveRecord::Migration
def change
create_table :vouchers do |t|
t.string :store_name
t.string :code
t.integer :savings
t.date :exp_date
t.belongs_to :user
end
end
end
These neat and simple lines are called macros which adds a number of methods to the class which are specialized according to the collection or association symbol and the options hash.
Lastly, for this project, we were required to implement a user login and authentication with the help of the bcrypt gem which is a hashing algorithm that helps store user passwords securely. In my project, this translated to adding a few lines of code including has_secure_password in the User model as well as using other methods such as user.authenticate() as per below:
def login(email,password)
user = User.find_by(:email => email)
if user && user.authenticate(password)
session[:user_id] = user.id
else
redirect '/login'
end
end
All in all, I really enjoyed putting this app together although there were moments when I thought I was ready to admit defeat. In these moments, it really helps to take a step back and approach the problem with fresh eyes. It also helps to have your notes and material at hand so that you can review the concepts when you are stuck.