ruby-on-rails - form_for in devise How it works?

Question

rails g devise:views command generated that view

<h2>Sign up</h2>

    <%= form_for(resource, :as => resource_name, :url => registration_path(resource_name))   do |f| %>
    <%= devise_error_messages! %>

   <div><%= f.label :username %><br />
   <%= f.text_field :username, :autofocus => true %></div>

  <div><%= f.label :email %><br />
  <%= f.email_field :email, :autofocus => true %></div>

  <div><%= f.label :password %><br />
  <%= f.password_field :password %></div>

  <div><%= f.label :password_confirmation %><br />
  <%= f.password_field :password_confirmation %></div>

  <div><%= f.submit "Sign up" %></div>
<% end %>

<%= render "devise/shared/links" %>

My question is how does it work " form_for(resource, : as=>resource_name, ..."

Answer 1

resource是简单的记录（或对象） - 对于设计，它通常是所谓的User或类似的东西。for 的其余参数form_for是选项，在form_for 文档中有详细说明。

Answer 2

我注意到 :email 和 :username 都在调用 email_field，这是一个错误。