Form validation in ruby on rails

Question

I have built a sign up page in ruby on rails. I want to validate this sign up form. For example - if user left any section blank, the form will show an error message. It will also check whether the given email is unique. How can I do this by not changing my form?

#This my logins_controller.rb file
class LoginsController < ApplicationController
skip_before_action :verify_authenticity_token
def index
    @subscriber=Subscriber.new()
end

def sign_up    
    subscriberNew = Subscriber.new
    subscriberNew.name = params[:name]
    subscriberNew.cus_user_name = params[:user_name]
    subscriberNew.cus_password = params[:password]
    subscriberNew.cus_email = params[:email]
    result = subscriberNew.save
    respond_to do |format|
        msg = { :status => "ok", :message => "Success!" }
        format.json  { render :json => msg }
    end
end





def validate_signup
    #what should i write here?
end

end

and this is my sign up form

<div class="container">
<div class="shadow-lg p-3 mb-5 bg-white rounded view-card">
    <h4 class="card-title">
    <a href="/product_types">
    <i class="material-icons">
      arrow_back_ios
    </i></a></h4>
    <form id="signup_form" method="post" action="/sign-up">
            <p class="h4 mb-4">Register to Binimoy</p>
            <label for="name">Name</label>
            <input type="text" name="name" id="name" class="form-control mb-4" placeholder="Name">

            <label for="email">Email</label>
            <input type="email" name="email" id="email" class="form-control mb-4" placeholder="Email">

            <label for="phone">Phone</label>
            <input type="text" name="phone" id="phone" class="form-control mb-4" placeholder="Phone">

            <label for="name">Password</label>
            <input type="password" name="password" id="password" class="form-control mb-4" placeholder="Password">

            <div class="form-row mb-4">
                <div class="col">
                    <button class="btn btn-default my-4 btn-block" type="reset">Reset</button>
                </div>
                <div class="col">
                <button type="button" class="btn btn-info my-4 btn-block" id="submitAnchor">Submit</button>
                </div>
            </div>                
    </form>
</div>

Answer 1

Rails is an framework with an strong opinion how to do things. You are doing things not the Rails way and this will make it more complicated.

If you really do not want to change your form (which is strongly advice against)

Add validations, check the return value of save and send back some error message

In your model:

validates :email, presence: true, uniqueness: true

In your controller:

if subscriber.save render json: {status: "ok", message: "success"} else render json: {status: "nok", message: "something went wrong"} end

Probably you should get rid of the status property and use the HTTP status code for this (sending back 201 (created) and 422 (unprocessble entity) responses instead)

Some other recommendatations to make your code more readable:

• Follow the Rails conventions (use a form builder, it simplifies the assignment of form params to the model

• Use Ruby naming conventions:

  subscriberNew

should be

subscriber_new

since Ruby uses camel_case but actually there is no need for the new suffix, so subscriber is enough

• Use two spaces for identation
• Don't abbreviate variables (cus_username, ...) and don't prefix when there is no need

Answer 2

First, use Rails helpers in your views and write your form as documented here.

<%= form_with url: sign_up_path do |form| %>
  <%= form.label :email %>
  <%= form.text_field :email %>
  ...
  <%= form.submit %>
<% end %>

Second, use validations in your Subscriber model as documented here.

validates :email, presence: true, uniqueness: true
...

Hope it helps ;)