Question

如何在表单重新显示时选择一个集合来显示所选的已提交值？例如，如果其他字段未验证，则多选框应显示所选项目

<%= collection_select(:coupon, :activity_ids,
                            current_user.provider.activities, :id, :name,
                            {},
                            {:multiple => true, :class => 'chosens-select',   :name=>'coupon[activity_ids][]'}) %>

Answer 1

这样的事情会发生。

<%= collection_select(:coupon, :activity_ids,current_user.provider.activities, 
:id, :name, {:selected => @coupon.activity_ids}, {:multiple => true, :class => 'chosens-select', :name=>'coupon[activity_ids][]'}) %>

Answer 2

我建议用户SimpleForm。你会做的：

simple_form_for(my_model) do |f|
  f.association :activities
  f.button :submit
end

它将简化您的所有表格。

Answer 3

感谢那些发布答案的人，它促使我放弃了＃34;修复＆＃34;表格再看看我的控制器。事实证明我在params声明中犯了一个错误：

def coupon_params
  params.require(:coupon).permit(:id, :provider_id, :code, :max_uses, :max_uses_per_customer, :name, :expires_at,
    :dollar_discount, :percent_discount, :starts_at, :activity_ids => {})
end

应该在哪里

def coupon_params
      params.require(:coupon).permit(:id, :provider_id, :code, :max_uses, :max_uses_per_customer, :name, :expires_at,
        :dollar_discount, :percent_discount, :starts_at, :activity_ids => [])
end

发现差异？ activity_ids应该是一个数组，而不是哈希

:activity_ids => []

收集选择has_many通过

3 个答案: