eg: <%= link_to "About Me", home_about_path %>
    #where home_about = prefix gave after you run the command "rails routes (for newer versions) or rake routes (for version below 6.0)

    #partials should start with "underscore" eg: _navbar.html.erb

    # Way 1 - use the request.path and include helper function/method to check if the current route contains the specific substring.
    request.path.include?"/edit"

    # Way 2 - You can use the current_page helper where you supply the specific controller and method used.
    # For some instances, this code below doesn't work with conditional if false.
    current_page?(controller: 'suppliers', action: 'edit')

    # Way 3 - since there are other pages for suppliers for example like new, edit and show. the link does not get highlighted so you can use
    # the controller_name so that all actions or pages under that controller will highlight the side bar
    controller_name === 'suppliers'

    # a "supplier" belongs to a user who created him/her. instead of user_id we created created_by field.
    # you can use the "created_by_user" to access the data from user model.
    belongs_to :created_by_user, class_name: 'User', foreign_key: 'created_by', optional: true

    # sample usage:
    @supplier.created_by_user.email

    #output
    #[email protected]

# on  models/supplier.rb
# name is the field to modify the error message whenever triggered.
validates :name, presence: { message: 'Supplier name is required.' }

# Change error.full_message to error.message
<%= form_with(model: supplier) do |form| %>
    <% if supplier.errors.any? %>
        <div class="mt-5">
            <% supplier.errors.each do |error| %>
                <div class="alert alert-warning alert-dismissible fade show font-monospace text-start" role="alert">
                    #from <%= error.full_message %> 
                    <%= error.message %>
                    <button type="button" class="btn-close" data-bs-dismiss="alert" aria-label="Close"></button>
                </div>
            <% end %>
        </div>
    <% end %>
<% end %>

    Model.column_names # shows the column names
    Model.all # shows all the data

    # 1. Drop the database
    rails db:drop

    # 2. Recreate it
    rails db:create

    # 3. Migrate the tablesS
    rails db:migrate

    #Note: This is only applicable for a development who still starting and use's dummy data. Doing this will wipe all the data on the existing database.

# eg. controllers/suppliers_controller.rb

# added the new fields such as :email, :point_person, :contact_number
def supplier_params
  params.require(:supplier).permit(:name, :email, :point_person, :contact_number, :created_by)
end