如何使用索引操作&索引模板？ [英] How to get the output of a nested form to stay in its exact original order, despite permutations, using the index action & index template?
问题描述
我正在使用嵌套表单发布Urls和文本。通过javascript，我允许这两个字段的任何排列，例如Url1 Text1 Text2 Url2或Url1 Text1 Url2 Text2等
I am using a nested form to post Urls and Texts. Via javascript, I am allowing any permutation of these two fields e.g. Url1 Text1 Text2 Url2 or Url1 Text1 Url2 Text2 etc
提交表单并重定向到index.html.view之后，我然后尝试保留我决定在表单中使用的任何排列的原始顺序，即是否决定发布Text1 Url1 Url2 Text2 Url3我需要完全相同的安排才能在浏览器中显示。
After submitting the form and redirecting to the index.html.view, I am then trying to keep the original order of whatever permutation I decide to use in the form i.e. if I decided to post Text1 Url1 Url2 Text2 Url3 I need that exact same arrangement to display in the browser.
邮政表格代码
Post Model
Post Model
class Post < ActiveRecord::Base
has_many :texts
has_many :urls
accepts_nested_attributes_for :texts, :urls
end
文本模型
class Text < ActiveRecord::Base
belongs_to :post
end
Url Model
Url Model
class Url < ActiveRecord::Base
belongs_to :post
end
Schema
ActiveRecord::Schema.define(version: 20160215123916) do
create_table "posts", force: :cascade do |t|
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
end
create_table "texts", force: :cascade do |t|
t.text "textattr"
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
t.integer "post_id"
end
add_index "texts", ["post_id"], name: "index_texts_on_post_id"
create_table "urls", force: :cascade do |t|
t.string "urlattr"
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
t.integer "post_id"
end
add_index "urls", ["post_id"], name: "index_urls_on_post_id"
end
Posts Controller
Posts Controller
class PostsController < ApplicationController
def index
@posts = Post.includes(:texts, :urls).all.order(created_at: :desc)
end
def new
@post = Post.new
end
def create
@post = Post.new(post_params)
if @post.save
redirect_to '/posts'
else
render 'new'
end
end
private
def post_params
params.require(:post).permit(:texts_attributes => [:textattr], :urls_attributes => [:urlattr])
end
end
Index.html.erb（尝试失败）
Index.html.erb (Unsuccessful Attempt)
<% @posts.each do |post| %>
<% post.texts.each do |text|%>
<%= text.textattr %> <br>
<% end %>
<% post.urls.each do |url|%>
<%= url.urlattr %> <br>
<% end %>
<% end %>
Index.html.erb（尝试失败）
Index.html.erb (Unsuccessful Attempt)
<% @posts.each do |post| %>
<% [post.texts, post.urls].flatten.sort_by { |c| [c.created_at] }.each do |content| %>
<% if content.class.name == "Text" %>
<%= content.textattr %>
<% elsif content.is_a? Url %>
<%= content.urlattr %>
<% end %>
<% end %>
<% end %>
推荐答案
为 Richard说，您需要添加订单列（或排名-调用列 order 会引起与生成的SQL的混淆。
As Richard says, you need to add an order column (or position - calling the column order can cause confusion with the generated SQL).
我认为主要问题是您的咖啡代码。您需要为添加的每一行生成一个隐藏的输入，并对添加的行使用单个 current_index 计数器：
I think the main issue is your coffeescript code. You need to generate a hidden input with each row you add, and use a single current_index counter for row you add:
current_index = 0
addText = ->
html = """
<br>
<textarea name="post[things_attributes][#{current_index}][text]" id="post_things_attributes_#{current_index}_text"></textarea>
<input type="hidden" name="post[things_attributes][#{current_index}][order]" id="post_things_attributes_#{current_index}_order" value="#{current_index}" />
"""
$("#new_post input[type='submit']").before(html)
current_index += 1
addUrl = ->
html = """
<br>
<input type="url" name="post[things_attributes][#{current_index}][url]" id="post_things_attributes_#{current_index}_url">
<input type="hidden" name="post[things_attributes][#{current_index}][order]" id="post_things_attributes_#{current_index}_order" value="#{current_index}" />
"""
$("#new_post input[type='submit']").before(html)
current_index += 1
在您的 index.html.erb ，请按 order 列对 Things 进行排序：
In your index.html.erb, order the Things by the order column:
<% @posts.each do |post| %>
<% post.things.order(:order).each do |thing| %>
<br>
<%= thing.try(:text) %>
<%= thing.try(:url) %>
<% end %>
<br>
<% end %>
还值得注意的是，这种动态嵌套表单模式茧宝石的处理非常好。建议您在项目中使用它。
It's also worth noting that this dynamic nested form pattern is very well-handled by the cocoon gem. I'd recommend taking a look and using that in your project.
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