bank-app

Ruby on Rails 5 Application with HAML and PostgreSQL

Table of contents

• General info
• Screenshots
• Technologies
• Setup
• Features
• Status
• Inspiration
• Contact

General info

Simple banking application written in Rails 5 where a user can perform withdrawals and deposit transactions. The purpose is to document the current practices in terms of organizing javascript, api code (Rails) and command patterns for business rules.

Bank account belongs to a client, a client can have many bank accounts.

I was learning how to create CRUD in Rails.

Screenshots

When we click "Add new transaction" a charming Modal appears to our eyes:

Technologies

• Ruby on Rails 5
• HAML
• jQuery
• PostgreSQL database

Setup

$ git clone https://github.com/lapinskap/bank-app
$ cd bank-app
$ bundle install
$ rails s

Operations in terminal

Add a client:

$ rails console
$ Client.create!(first_name: "Juan", middle_name: "Pablo", last_name: "Fernandez", client_number: "42034823") 
$ client = Client.last
$ exit

Rails model will change clients name to uppercase letters

Create Bank Account:

$ rails console
$ BankAccount.create!(client: client, account_number: "000000001")
$ exit

client: client <- client name defined while creating a client

default balance is $0.00

Delete history of transactions:

$ rails console
$ AccountTransaction.destroy_all

or delete last transaction:

$ AccountTransaction.last.destroy!
$ exit

$ rails s

Code Examples

Module example

app/models/account_transaction.rb

class AccountTransaction < ApplicationRecord
  belongs_to :bank_account

  TRANSACTION_TYPES = ["withdraw","deposit"]

  validates :bank_account, presence: true
  validates :amount, presence: true, numericality: true
  validates :transaction_number, presence: true, uniqueness: true
  validates :transaction_type, presence: true, inclusion: { in: TRANSACTION_TYPES}

  before_validation :load_defaults

  def load_defaults
    if self.new_record?
      self.transaction_number = SecureRandom.uuid
    end
  end
end

Validate new transaction

app/operations/bank_accounts/validate_new_transaction.rb

module BankAccounts
    class ValidateNewTransaction
        def initialize(amount: , transaction_type: , bank_account_id: )
            @amount = amount.try(:to_i) 
            @transaction_type = transaction_type
            @bank_account_id = bank_account_id
            @bank_account = BankAccount.where(id: @bank_account_id).first
            @errors = []
        end

        def execute!
            validate_existence_of_account!

            if @transaction_type == "withdraw" and @bank_account.present?
                validate_withdrawal!
            end
            @errors
        end

        private

        def validate_withdrawal!
            if @bank_account.balance - @amount < 0.00
                @errors << "Not enough money"
            end
        end

        def validate_existence_of_account!
            if @bank_account.blank?
                @errors << "Account not found"
            end

        end
    end
end

HAML example

<div class="container">
 <div class="row">
  <div class="col-md-12"></div>
 </div>
</div>

%div.container
 %div.row
  %div.col-md-12

.container
 .row
  .col-md-12

Features

List of features ready and TODOs for future development

• HAML files
• Ajax calls

To-do list:

• Add styles!
• Solve the problem with the lack of javascript precompile in heroku server

Status

Project is: in progress

Inspiration

An idea for an application that I liked very much - Inspired by devlogs youtube videos - I decided that I want to do my own version of "simple banking app". It seems easy for me to expand in the future.

Contact

Created by @lapinskap - feel free to contact me!