Ruby on Rails -- f.select 中的多项选择
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Ruby on Rails -- multiple selection in f.select
提问by Kim
I have the following select box in my form:
我的表单中有以下选择框：
Related Type: <%= f.select(:TYPE, [['Type A', 'Type A'],
['Type B', 'Type B'],
['Type C', 'Type C'],
['Type D', 'Type D'],
['Type E', 'Type E']
],{ :prompt => "Please select"}
) %>
I want to allow the user to make multiple selections and also make the size of the select box 5.
我想允许用户进行多项选择，并将选择框的大小设置为 5。
How to do that for the code above?
如何为上面的代码做到这一点？
回答by mikej
After your { :prompt => "Please select"}add another hash with html options e.g.
在您{ :prompt => "Please select"}添加另一个带有 html 选项的哈希后，例如
<%= f.select(:TYPE, [['Type A', 'Type A'],
['Type B', 'Type B'],
['Type C', 'Type C'],
['Type D', 'Type D'],
['Type E', 'Type E']
],{ :prompt => "Please select"},
{ :multiple => true, :size => 5 }
) %>
Once you've done this you might want to move your :promptoption (keep the empty {}though so that html attributes don't get treated as Rails options.)
完成此操作后，您可能希望移动您的:prompt选项（{}尽管保留为空，以便 html 属性不会被视为 Rails 选项。）
Also you'll need to ensure your controller code is correctly accepting and handling multiple values.
此外，您还需要确保您的控制器代码正确接受和处理多个值。
回答by Swathi
In case of collection, try
在收集的情况下，尝试
<%= f.select(:TYPE, Categories.collect {|p| [ p.name, p.id ] },
{ :prompt => "Please select"},
{ :multiple => true, :size => 5 }) %>
回答by Augustin Riedinger
I have a fully working example (including preselection when editing the object), when:
我有一个完整的示例（包括编辑对象时的预选），当：
Objectis the considered objectsimilar_idsis the key to relations, and is astring
Object是被考虑的对象similar_ids是关系的关键，是一个string
In the form:
在形式：
form_for(@object) do |f|
= f.select :similar_ids, options_from_collection_for_select(Object.all, :id, :name, {:selected => @object.similar_ids.split(';')}), {}, {:multiple => true, :size => 4, :name => 'object[similar_ids][]'}
And in the Object.rbmodel:
在Object.rb模型中：
class Object < ActiveRecord::Base
before_save :handle_similars
def handle_similars
self.similar_ids = self.similar_ids.select(&:present?).join(';')
# .select(&:present?) is necessary to avoid empty objects to be stored
end
def similars
self.class.find(self.similar_ids.split(';'))
end
end
These posts helped me out:
这些帖子帮助了我：
- Select tag with multiple values pre-selected - Values inserted manually in database
- Ruby on Rails: Submitting an array in a form
Hope it helps
希望能帮助到你
回答by Sanjay Choudhary
HTML
HTML
<%= form.select(:product_ids, Product.all.collect {|p| [ p.name, p.id ] },
{ :prompt => "Please select"},
{ :multiple => true, :size => 5 }) %>
Controller
控制器
@category = Category.new(category_params)
def category_params
params.require(:category).permit(:name, product_ids: [])
end
回答by ysk
{ :prompt => "Please select"}, { :multiple => true, :size => 5 } {} is important when f.select
{ :prompt => "Please select"}, { :multiple => true, :size => 5 } {} 在 f.select 时很重要
