我正在尝试基于此示例实现可排序列表功能 - http://railscasts.com/episodes/147-sortable-lists-revised。
问题是，当我放下我的元素时，我不断收到以下错误消息：
Started POST "/applications/sort" for 127.0.0.1 at 2012-12-04 11:14:45 -0600
Processing by ApplicationsController#sort as */*
Parameters: {"application_application_field_attributes_0"=>["id"], "application_application_field_attributes_1"=>["id"], "application_application_field_attributes_2"=>["id"]}
Completed 500 Internal Server Error in 1ms
NoMethodError (undefined method `each_with_index' for nil:NilClass):
app/controllers/applications_controller.rb:91:in `sort'
视图/应用程序/_form.html.erb
<%= form_for(@application, :class => "main") do |f| %>
...
<div class="sortable" data-update-url="<%= sort_applications_url %>">
<%= f.fields_for :application_field do |fields| %>
<%= render 'application_field_fields', f: fields %>
<% end %>
</div>
<% end %>
视图/应用程序/_application_field_fields.html.erb
<div class="formRow" id="<%= f.object.position %>">
<div class="grid2"><%= f.label :field_name %></div>
<div class="grid3"><%= f.text_field :field_name %></div>
<div class="grid2"><%= f.label :field_type %></div>
<div class="grid3"><%= f.text_field :field_type %></div>
<!-- Need to store the hidden field _destroy here so we can access it via jQuery -->
<%= f.hidden_field :_destroy %>
<div class="grid2" align="center"><%= link_to "Remove", '#', class: "remove_fields"%></div>
<div class="clear"></div>
</div>
应用程序.js
$('.sortable').sortable({
placeholder: "ui-state-highlight",
forcePlaceholderSize: true,
start: function(event, ui) {
ui.item.addClass('dragging');
},
stop: function(event, ui) {
ui.item.removeClass('dragging');
},
update: function(event, ui) {
$.post($(this).data('update-url'), $(this).sortable('serialize'));
}
});
控制器/应用程序#sort
# POST /applications/sort
def sort
puts '*********'
puts '#####'
puts 'params = ' #{params}
puts '********'
params[:application].each_with_index do |id, index|
Application.update_all({position: index+1}, {id: id})
end
render :nothing => true
end
当我删除一个可排序的元素时，你可以看到我的参数哈希是空的。为什么会这样，我该如何解决？
编辑
我将发布我的模型，以便您查看关系
class Application < ActiveRecord::Base
belongs_to :company
has_many :application_field, :order => "position"
accepts_nested_attributes_for :application_field, :allow_destroy => true
attr_accessible :application_name, :application_field_attributes
end
class ApplicationField < ActiveRecord::Base
belongs_to :application
has_many :application_fields_value
attr_accessible :field_name, :field_type, :field_value, :application_field_values_attributes
accepts_nested_attributes_for :application_fields_value, :allow_destroy => true
end