How do I pass form variables from views to controllers in Rails 4? - forms

Question

I'm trying to accept telephone numbers in a simple form and I can't seem to get it to pass the variable through to the controller. The code I have so far is:
view on /users/new.erb:
<%= form_for #user do |f| %>
<%= field_set_tag do %>
<p><%= f.label :phone %><br>
<%= f.text_field :phone%>
<%= f.submit "Submit" %>
<% end %>
<% end %>
and in the controller I have:
def new
#user = User.new
end
def create
#user = User.new(params[:new])
phone = #user.phone
end
Any help would be greatly appreciated. Thanks.

Answer 1

There are a few problems with your code. When you write:
<%= form_for #user %>
All the form fields are sent to the controller in the form of a hash with "user" as the root. Just like
{"user": {"phone": "ENTERED PHONE NUMBER"}}
To access these fields in the controller you need to use the following method:
#phone_number = params[:user][:phone]
One More Important Thing
For security purposes rails does uses Strong Parameters. It means that you can't use the form parameters directly in Active Model for mass assignment like this:
#user = User.new(params[:user])
You need to permit all the fields explicitly for mass assignment. This can be achieved as follows.
def create
#user = User.new(params_user)
#user.save
end
private
def params_user
params.require(:user).permit(:phone)
end

Answer 2

params[:new] just passes the parameter :new to your #user object, but there is no params[:new] parameter because it is not defined in your form. params[:phone] should be passed to '#user' just params if you want all available params that were submitted.
Try
#user = User.new(params) #instead of #user = User.new(params[:new])
#user.phone