如何使用 :selected with grouped_collection_select [英] How to use :selected with grouped_collection_select

问题描述

是否可以通过 grouped_collection_select 函数以某种方式使用您在普通选择视图助手上使用的 :selected 选项?我想设置在我的列表中预先选择的值.我试过传入 :selected 作为一个没有运气的选项！

Is it possible to somehow use the :selected option that you'd use on a normal select view helper with the grouped_collection_select function? I'd like to set the value that gets pre-selected in my list. I've tried passing in :selected as an option with no luck!

这是我测试的一些代码片段:

Here's some code snippts of my tests:

grouped_collection_select 'user[subscription_attributes]', :subscription_plan_id, Trade.order(:name).all, :subscription_plans, :name, :id, :display_name, { :include_blank => true, :selected => 5 }

grouped_collection_select 'user[subscription_attributes]', :subscription_plan_id, Trade.order(:name).all, :subscription_plans, :name, :id, :display_name, :include_blank => true, :selected => 5 

两个版本都不行.未设置选择.我正在使用它来设置嵌套模型的值.我正在使用 railscasts 动态选择列表方法:http://railscasts.com/episodes/88-dynamic-select-menus-revised

Neither version works. No selected is set. I'm using this to set a value for a nested model. I'm using the railscasts dynamic select list methods: http://railscasts.com/episodes/88-dynamic-select-menus-revised

我无法让 formtastic 很好地与组选择一起玩，所以我不得不手动完成，但当用户验证失败时，我不会保持选中此值.我想在他们修复验证错误时保留这个设置.

I couldn't get formtastic to play nicely with the group selects so I had to do it by hand but I don't keep this value selected when a user fails validations. I'd like to keep this set when they fix validation errors.

推荐答案

我刚刚遇到了同样的问题，并使用 option_groups_from_collection_for_select helper 和 select helper 文档解决了它在:http://api.rubyonrails.org/classes/ActionView/Helpers/FormOptionsHelper.html.

I just ran across the same problem and solved it using the option_groups_from_collection_for_select helper and the select helper documented at: http://api.rubyonrails.org/classes/ActionView/Helpers/FormOptionsHelper.html.

第一步是创建分组选项.以您的示例为例，它应该如下所示:

The first step is to create the grouped options. Taking your example, it should look like:

<% options = option_groups_from_collection_for_select(Trade.order(:name).all,
   :subscription_plans, :name, :id, :display_name, 5) %>

然后我创建了选择对象，如:

Then I created the select object like:

<%= select('user[subscription_attributes]', :subscription_plan_id, options, 
  include_blank: true) %>

你可以在一行中写出所有内容，我只是将选项分解到一个单独的变量中以说明两种不同的方法.

You could write it all out in one line, I just broke out the options into a separate variable to illustrate the two different methods.

这篇关于如何使用 :selected with grouped_collection_select的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！