Rails has_many :through 和 collection_select 与多个 [英] Rails has_many :through and collection_select with multiple
问题描述
我在使用 has_many 时遇到以下问题:通过 collection_select 的多选中的多对多关系:multiple => true.我有供应商可以交付许多供应商可以交付的许多成分.看看:
I have the following problem using a has_many :through many-to-many relation in a multi-select via collection_select :multiple => true. I have Suppliers who deliver many Ingredients which can be delivered by many Suppliers. Have a look:
成分模型:
class Ingredient < ActiveRecord::Base
has_many :ingredient_suppliers
accepts_nested_attributes_for :ingredient_suppliers, :allow_destroy => true
has_many :suppliers, :through => :ingredient_suppliers
end
供应商模型:
class Supplier < ActiveRecord::Base
has_many :ingredient_suppliers
has_many :ingredients, :through => :ingredient_suppliers
end
关系实体:
class IngredientSupplier < ActiveRecord::Base
belongs_to :ingredient
belongs_to :supplier
end
这是表格.请注意,如果不指定 :name:
And this is the form. Note that I could not get it to work without specifying the :name:
<%= form_for(@ingredient) do |f| %>
<%= f.fields_for :suppliers do |supplier_fields| %>
<%= supplier_fields.collection_select (:supplier_ids,
Supplier.all(:order=>"name ASC"),
:id, :name,
{:selected => @ingredient.supplier_ids,
:include_blank => true},
{:multiple => true,
:name => 'ingredient[supplier_ids]'}) %>
<% end %>
<% end %>
如果我删除:name,则会收到此错误消息:
If I remove the :name, then I get this error message:
Supplier(#-617951108) expected, got Array(#-608411888)
Request
Parameters:
{"commit"=>"Anlegen",
"authenticity_token"=>"MuEYtngwThharmM1KaAbH8JD3bScXiDwj0ALMytxl7U=",
"_method"=>"put",
"utf8"=>"✓",
"id"=>"1",
"ingredient"=>{"name"=>"Ingredient 1",
"nr"=>"00100",
"unit"=>"kg",
"mol_per_unit"=>"2000,
00000",
"description"=>"",
"suppliers"=>{"supplier_ids"=>["1",
"2"]}}}
现在的问题是,PUT 参数只包含一个供应商 ID,而不是供应商 ID 数组:
The problem now is, that the PUT parameters only contain one supplier_id instead of an array of supplier_ids:
"ingredient"=>{"name"=>"Rohstoff 3", "nr"=>"00300", "unit"=>"Stk.", "mol_per_unit"=>"0,00000", "description"=>"", "supplier_ids"=>"2"}
推荐答案
我已经解决了问题.在这种情况下,使用 fields_for 是错误的.解决方案是使用 collection_select,如下所示:
I've got the problem solved. In this case, using fields_for was the error. The solution is using a collection_select, like this:
<%= collection_select(:ingredient, :supplier_ids,
Supplier.all(:order=>"name ASC"),
:id, :name, {:selected => @ingredient.supplier_ids, :include_blank => true}, {:multiple => true}) %>
这篇关于Rails has_many :through 和 collection_select 与多个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!