show user's first_name with devise - ruby-on-rails

Question

How to show user's first_name in page like "Hello, current_user.first_name", my schema
create_table "users", force: :cascade do |t|
t.string "email", default: "", null: false
t.string "encrypted_password", default: "", null: false
t.string "first_name", default: "", null: false
t.string "last_name", default: "", null: false
t.string "reset_password_token"
t.datetime "reset_password_sent_at"
t.datetime "remember_created_at"
t.integer "sign_in_count", default: 0, null: false
t.datetime "current_sign_in_at"
t.datetime "last_sign_in_at"
t.string "current_sign_in_ip"
t.string "last_sign_in_ip"
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
t.index ["email"], name: "index_users_on_email", unique: true
t.index ["reset_password_token"], name: "index_users_on_reset_password_token", unique: true
end
when i tried to do in my page <span>Hello, <%= current_user.email %></span> it's all ok, but whet i tried <span>Hello, <%= current_user.first_name %></span> it's show nothing. Where is my mistake?

Answer 1

The problem here is in your schema, you have t.string "first_name", default: "", null: false which saves the empty string in your database, if you don't pass the first_name.I'm quite sure you are not saving the first_name value to user anyhow and it is by default set to "". When you try to access <span> <%= "Hello, #{current_user.first_name}" %></span> here it return empty string.Here user is present as if user is not present then it would have given error as first_name for nil:NilClass.
add this to your ApplicationController
before_action :configure_permitted_parameters, if: :devise_controller?
protected
def configure_permitted_parameters
permit_attrs(%i[first_name last_name])
end
def permit_attrs(attrs)
%i[sign_up account_update].each do |action|
devise_parameter_sanitizer.permit(action, keys: attrs)
end
end
in your new.html.erb you have two first name field change one as below:
<div class="field">
<%= f.label :first_name %><br />
<%= f.text_field :first_name, autofocus: false, class: "form-control" %>
</div>
to
<div class="field">
<%= f.label :last_name %><br />
<%= f.text_field :last_name, autofocus: false, class: "form-control" %>
</div>

Answer 2

So if you are seeking to display user information, this is how I handle that.
Display User Input Fields
<p> Hello <%= #user.first_name %>
Now, if you want to be able to show user input information IF they have it.
If User Filled Out Form
<% if #user.first_name? %>
<p>Hello, <%= #user.first_name %></p>
<% else %>
<p>Hello Anonymous User</p>
<% end %>