Question

我在_form.html.haml部分中有以下代码，它用于新建和编辑操作。（我使用Ryan Bates的插件nested_form）

.fields
    - f.fields_for :transportations do |builder|
        = builder.collection_select :person_id, @people, :id, :name, {:multiple => true}
        = builder.link_to_remove 'effacer'
    = f.link_to_add "ajouter", :transportations

适用于新动作...... 对于编辑操作，如文档中的解释，我要添加：已存在关联的id，所以，我要添加类似

的内容

= builder.hidden_field :id, ?the value? if ?.new_record?

我如何获得价值？

以下是accepts_nested_attributes_for的文档以供参考（来源：http://github.com/rails/rails/blob/master/activerecord/lib/active_record/nested_attributes.rb#L332）

# Assigns the given attributes to the collection association.
#
# Hashes with an <tt>:id</tt> value matching an existing associated record
# will update that record. Hashes without an <tt>:id</tt> value will build
# a new record for the association. Hashes with a matching <tt>:id</tt>
# value and a <tt>:_destroy</tt> key set to a truthy value will mark the
# matched record for destruction.
#
# For example:
#
# assign_nested_attributes_for_collection_association(:people, {
# '1' => { :id => '1', :name => 'Peter' },
# '2' => { :name => 'John' },
# '3' => { :id => '2', :_destroy => true }
# })
#
# Will update the name of the Person with ID 1, build a new associated
# person with the name `John', and mark the associatied Person with ID 2
# for destruction.
#
# Also accepts an Array of attribute hashes:
#
# assign_nested_attributes_for_collection_association(:people, [
# { :id => '1', :name => 'Peter' },
# { :name => 'John' },
# { :id => '2', :_destroy => true }
# ])

感谢您的帮助。

Answer 1

我发现了我的错误，这是我学到的事情：

当您对多个关联使用accepts_nested_attributes_for时，请保留关联表的：id主键。

干杯

Answer 2

当使用“：_delete”而不是“：_destroy”时，我的工作正常。我在轨道上2.3.4。 Ruby 1.8.7

看看这个：http://api.rubyonrails.org/classes/ActionView/Helpers/FormHelper.html#M001605

Answer 3

Rails正式支持嵌套表单。您正在做的事情（特别是使用fields_for方法）可能与RAils渲染fields_for的内置方式相冲突。

以下是Rails方法做field_for的文档......它非常彻底：

http://api.rubyonrails.org/classes/ActionView/Helpers/FormHelper.html#M001605

我强烈建议您尝试使用内置方式而不是插件，因为这种方式几乎可以无限期地得到支持。

希望这有帮助！

accepts_nested_attributes_for和nested_form插件

3 个答案: