Ruby-on-rails rails 选择带有多个预选值的标签
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rails select tag with multiple values pre selected
提问by Omnipresent
I am trying to have a multiple select box. select box will contain all the stores in the DB but the ones that the user belongs to will be selected.
我想有一个多选框。选择框将包含数据库中的所有商店，但将选择用户所属的商店。
I'm half way there. I got a select box which has all the stores in the database. I'm unable to select the ones that the user belongs to.
我已经到了一半。我有一个选择框，其中包含数据库中的所有商店。我无法选择用户所属的那些。
I have the following:
我有以下几点：
<%= select_tag 'stores[]', options_for_select(@stores.map {|s| [s.store_name, s.store_id]},
:selected => @user.stores.map {|j| [j.store_name, j.store_id]}), :multiple => true, :size =>
10 %>
I have a map with stores that a user belongs to. it is in:
我有一张地图，上面有用户所属的商店。它在：
@user.stores
回答by Omnipresent
after a fair amount of trial and error the following worked for me:
经过大量的反复试验后，以下对我有用：
<%= select_tag 'stores[]', options_for_select(@stores.map { |s| [s.store_name, s.store_id] }, @user.stores.pluck(:id)), multiple: true, size: 10 %>
回答by Michael Yagudaev
Another way of doing this would be to use the options_from_collection_for_selecthelper method. It will look something like this:
另一种方法是使用options_from_collection_for_select辅助方法。它看起来像这样：
<%= select_tag 'stores[]', options_from_collection_for_select(@stores, :store_id, :store_name, [4,5,6]), multiple: true, size: '10%' %>
