Rails form_for 不使用值填充字段

Question

I would like to use form_for with a non-activerecord model.

The problem is that the value of the fields is not initialized properly: it is always blank, even if the attribute is present.

For example this works:

@customer = Customer.retrieve_from_api(id)
@customer.billing_address.first_name # => "Marco"

But the form isn't initialized properly:

<%= form_for @customer, as: :customer, url: billing_info_path, method: :put do |f| %>
  ...
  <%= f.fields_for :billing_address do |b| %>
    <div class="field">
      <%# this is always blank (i.e. the initial value of the field is "") %>
      <%= b.text_field :first_name %>
    </div>

BTW I know that I could use form_tag , text_field_tag and initialize the value explicitly, but I would like to avoid that and keep the code DRY since I have many fields

Answer 1

您必须将@customer.billing_address作为参数传递给f.fields_for才能使其工作：

<%= f.fields_for :billing_address, @customer.billing_address do |b| %>