获取嵌套参数 [英] Get nested params

问题描述

我有一个带有嵌套参数的表单.在以下示例中，如何获取控制器中的amount_whole"值?

I have a form with nested params. In the following example, how do I get the "amount_whole" value in the controller?

    Parameters: {"utf8"=>"✓", "authenticity_token"=>"KCmBI6RLh0LdUsM2r5H1vhNykS1IXecFe5Lct+TuIGc=", "dec_declaration"=>{"declaration_nr"=>"SAL_2012_0001", "dec_declarationlines_attributes"=>{"0"=>{"amount_whole"=>"75"}}

是这样的吗?

amount = params[:dec_declarations][:dec_declarationlines_attributes][:amount_whole]

推荐答案

您忘记了散列中的 "0" 索引.所以你应该能够像这样访问它:

You forgot the "0" index in the hash. So you should be able to access it like this:

amount = params[:dec_declaration][:dec_declarationlines_attributes]["0"][:amount_whole]

params 散列可以使用符号和字符串作为键.

The params hash works with both symbols and strings as keys.

但是，从购买参数的结构来看，您似乎有一个名为 DecDeclaration 的模型，该模型具有该关联的多个 DecDeclarationlines 和 accepts_nested_attributes.所以你应该可以在控制器中像这样使用它:

However, judging buy the structure of the params it looks like you have a model called DecDeclaration which has_many DecDeclarationlines and accepts_nested_attributes for that association. So you should be able to use it like this in the controller:

@dec_declaration = DecDeclaration.build(params[:dec_declaration])
@amount_whole = @dec_declaration.dec_declarationlines.first.amount_whole

因为如果 params 出现在那个结构中，它会自动将嵌套的值分配给关联.

Because if the params comes in that structure, it will automatically assign the nested values to the association.

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