在应用程序启动时，我想用随机数据生成 10 个人。当我这样做时，我希望能够按类别异步过滤它们。这是代码：
型号代码：
class Person
attr_accessor :name, :text, :category, :timeStamp
end
控制器代码：
class PersonController < ApplicationController
def index
@persons = []
@categories = ["history", "science", "religion"]
10.times do
person = Person.new
person.name = [*('A'..'Z')].sample(8).join
person.text = [*('A'..'Z')].sample(64).join
person.category = @categories.sample
person.timeStamp = Time.at(rand * Time.now.to_i)
@persons.append(person)
end
end
def loadPersonsByCategory
@filteredPersons = @persons.where(:category => params[:category])
render :json => @filteredPersons
end
end
查看代码：
<div id="personsTitle">Persons details</div>
<div id="gridFilter">
<label class="personText">Show persons from</label>
<select id="filterCategory">
<option selected="selected">All</option>
<% @categories.each do |category| %>
<option value="<%= category %>"><%= category %></option>
<% end %>
</select>
<label class="personText">categories</label>
</div>
<div id="personsGrid">
<div class="gridRow gridHeader">
<div class="gridItem"><label class="personText">Name</label></div>
<div class="gridItem"><label class="personText">Person's text</label></div>
<div class="gridItem"><label class="personText">Category</label></div>
<div class="gridItem"><label class="personText">Time stamp</label></div>
</div>
<div id="gridBody">
<% @persons.each do |person| %>
<div class="gridRow">
<div class="gridItem"><label class="personText"><%= person.name %></label></div>
<div class="gridItem"><label class="personText"><%= person.text %></label></div>
<div class="gridItem"><label class="personText"><%= person.category %></label></div>
<div class="gridItem"><label class="personText"><%= person.timeStamp %></label></div>
</div>
<% end %>
</div>
<div class="gridRow gridFooter">
<div class="gridItem"><label class="personText">First</label></div>
<div class="gridItem"><label class="personText"><</label></div>
<div class="gridItem"><label class="personText">1</label></div>
<div class="gridItem"><label class="personText">2</label></div>
<div class="gridItem"><label class="personText">3</label></div>
<div class="gridItem"><label class="personText">></label></div>
<div class="gridItem"><label class="personText">Last</label></div>
JavaScript 代码：
$(function(){
$('#filterCategory').on('change', FilterCategories);
});
function FilterCategories(){
$.ajax(
{
type: "POST",
url: "/person/loadPersonsByCategory",
data: { category: $(this).val() },
contentType: "application/json; charset=utf-8",
dataType: "json",
success: function (result) {
var persons = [];
for (var i = result.length; i--; ) {
persons.push('<div class="gridRow">' +
'<div class="gridItem"><label class="personText">' + result[i].name + '</label></div>' +
'<div class="gridItem"><label class="personText">' + result[i].text + '</label></div>' +
'<div class="gridItem"><label class="personText">' + result[i].category + '</label></div>' +
'<div class="gridItem"><label class="personText">' + result[i].timeStamp + '</label></div>' +
'</div>');
}
$('<div/>', { 'class': 'filterResult', html: persons.join('')}).appendTo('#gridBody');
},
error:function (xhr, ajaxOptions, thrownError){
alert(xhr.status);
alert(thrownError);
}
});
}
在我尝试使用 ajax 过滤人员之前，一切都很好。我收到 500 内部服务器错误。什么可能导致此错误？非常感谢！
Plus 服务器错误日志
Started POST "/Person/loadPersonsByCategory" for 127.0.0.1 at 2012-06-01 19:09:07 +0200
Processing by PersonController#loadPersonsByCategory as JSON
Parameters: {"category"=>"religion"}
Completed 500 Internal Server Error in 1ms
NoMethodError (undefined method `where' for nil:NilClass):
app/controllers/person_controller.rb:17:in `loadPersonsByCategory'
路线.rb：
TestAssignment::Application.routes.draw do
get "person/index"
match "/Person/loadPersonsByCategory", :controller => "person", :action => "loadPersonsByCategory"
# The priority is based upon order of creation:
# first created -> highest priority.
# Sample of regular route:
# match 'products/:id' => 'catalog#view'
# Keep in mind you can assign values other than :controller and :action
# Sample of named route:
# match 'products/:id/purchase' => 'catalog#purchase', :as => :purchase
# This route can be invoked with purchase_url(:id => product.id)
# Sample resource route (maps HTTP verbs to controller actions automatically):
# resources :products
# Sample resource route with options:
# resources :products do
# member do
# get 'short'
# post 'toggle'
# end
#
# collection do
# get 'sold'
# end
# end
# Sample resource route with sub-resources:
# resources :products do
# resources :comments, :sales
# resource :seller
# end
# Sample resource route with more complex sub-resources
# resources :products do
# resources :comments
# resources :sales do
# get 'recent', :on => :collection
# end
# end
# Sample resource route within a namespace:
# namespace :admin do
# # Directs /admin/products/* to Admin::ProductsController
# # (app/controllers/admin/products_controller.rb)
# resources :products
# end
# You can have the root of your site routed with "root"
# just remember to delete public/index.html.
root :to => 'person#index'
# See how all your routes lay out with "rake routes"
# This is a legacy wild controller route that's not recommended for RESTful applications.
# Note: This route will make all actions in every controller accessible via GET requests.
# match ':controller(/:action(/:id))(.:format)'
end