使用 Rails 4 的 HABTM 关系的多选问题 [英] Multiple select issue with a HABTM relationship using Rails 4

问题描述

虽然代码似乎是正确的，但当我尝试发送表单时，没有发送多选的值.

Although the code seems to be right, when I try to send the form, the values of the multiple select aren't being sent.

如果我只是删除多个选项，那么考虑到一个值，一切都按预期工作，但重要的是要为每个事务存储一个以上的标签.

If I just remove the multiple option, everything works as expected considering just one value, but it's important to store more than one tag per transaction.

模型

Transaction.rb

class Transaction < ActiveRecord::Base
    has_and_belongs_to_many :tags

Tag.rb

class tag < ActiveRecord::Base
    has_and_belongs_to_many :transactions

查看

<%= form.collection_select :tag_ids, @tags, :id, :name, {}, 
    {:multiple => true} %>

结果:

<select id="transaction_tag_ids" multiple="multiple" name="transaction[tag_ids][]">  
    <option value="1">..</option>
</select>

推荐答案

确保您正确允许接收的参数用于批量分配.

Be sure what you properly allow received params for mass assignment.

你说 one param 有效，所以我假设你在控制器的某个地方有这样的东西:

You said that the one param works, so I assume what you have somewhere in your controller something like:

params.require(:transaction).permit(:name, :tag_ids)

所以你需要允许接收一个数组:

So you need allow to receive an array:

params.require(:transaction).permit(:name, :tag_ids => [])

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