Question

According to the Rails Guides and this Railscasts episode, when there s a one-to-many association between two objects (e.g. Project and Task), we can submit multiple instances of Task together with the Project during form submission similar to this:

<% form_for :project, :url => projects_path do |f| %>
  <p>
    Name: <%= f.text_field :name %>
  </p>
  <% for task in @project.tasks %>
    <% fields_for "project[task_attributes][]", task do |task_form| %>
      <p>
        Task Name: <%= task_form.text_field :name %>
    Task Duration: <%= task_form.text_field :duration %>
      </p>
    <% end %>
  <% end %>
  <p><%= submit_tag "Create Project" %></p>
<% end %>

This will result multiple copies of an HTML block like this in the form, one for each task:

<p>
    Task Name: <input name="project[task_attributes][name]">
    Task Duration: <input name="project[task_attributes][duration]">
</p>

My question is, how does Rails understand which

    (project[task_attributes][name], project[task_attributes][duration])

belong together, and packing them into a hash element of the resulting array in params? Is it guaranteed that the browsers must send the form parameters in the same order in which they appear in the source?

Answer 1

是的,定购单作为人保留,因为“k-everest Self-answered”是对原始问题的评论。

Those asking for HTML, see the guide on how the attribute s name is parsed.

Example of typically bad ordering:

cart[items][][id]=5
cart[items][][id]=6
cart[items][][name]=i1
cart[items][][name]=i2

而铁路则将铁路划入:

{ "cart"=> {"items"=> [
                        {"id"=>"5"},
                        {"id"=>"6", "name"=>"i1"},
                        {"name"=>"i2"}
                       ]}}

例源:https://spin.atomicobject.com/07/11/get-and-post-paraile-parsing-in-rails-2/

该特征在铁路初期投入使用,方法名称为build_deep_hash。欲了解更多的历史,ski起火/se,并自此结束起担任最后职务:。

Answer 2

如果你用直截了当的数据进行工作,并希望在不使用任何这些@objects的情况下再发送一个阵列。

<%= form_for :team do |t| %>
  <%= t.fields_for  people[] , [] do |p| %>
    First Name: <%= p.text_field :first_name %>
    Last Name: <%= p.text_field :last_name %>
  <% end %>
<% end %>

您的寄生虫数据应如上。

"team" => {
  "people" => [
    {"first_name" => "Michael", "last_name" => "Jordan"},
    {"first_name" => "Steve", "last_name" => "Jobs"},
    {"first_name" => "Barack", "last_name" => "Obama"}
  ]
}

友情链接