How to Force the User to Complete the Whole Form? - ruby-on-rails

Question

I am creating a Sing Up form. I need the user to complete every field of the form, but the rails only blocks the creation when there is no password. What I have to do to force the user to complete the whole form before submiting?
Here's my form code:
<%= form_for(user) do |f| %>
<% if user.errors.any? %>
<div id="error_explanation">
<h2><%= pluralize(user.errors.count, "error") %> prohibited this user from being saved:</h2>
<ul>
<% user.errors.full_messages.each do |message| %>
<li><%= message %></li>
<% end %>
</ul>
</div>
<% end %>
<div class="field">
<%= f.label :first_name %>
<%= f.text_field :first_name %>
</div>
<div class="field">
<%= f.label :last_name %>
<%= f.text_field :last_name %>
</div>
<div class="field">
<%= f.label :email %>
<%= f.text_field :email %>
</div>
<div class="field">
<%= f.label :password %>
<%= f.password_field :password %>
</div>
<div class="field">
<%= f.label :password_confirmation %>
<%= f.password_field :password_confirmation %>
</div>
<div class="field">
<%= f.label :fav_team, "Favorite Team" %>
<%= collection_select(:user, :fav_team, League.order(:name), :id, :name, {:include_blank => "Select a League"}, { :id => "leagues_select"}) %>
<%= grouped_collection_select(:user, :fav_team, League.order(:name), :teams, :name, :id, :name, {:include_blank => true}, {}) %>
</div>
<div class="field">
<%= f.label :net_worth, "Net Worth (USD)" %>
<%= f.text_field :net_worth, :readonly => true, :value => "100" %>
</div>
<div class="field">
<%= f.label :country %>
<%= f.select :country, options_for_Countrys, :include_blank => true %>
</div>
<div class="actions">
<%= f.submit %>
</div>
<% end %>

Answer 1

You have to write validations in your models to make sure the data is valid and present.
In your case you have to do something like this
class User < ApplicationRecord
validates :first_name, presence: true, length: { maximum: 50 }
validates :last_name, presence: true, length: { maximum: 50 }
end
You can check here for more information