＃< ActiveRecord :: ConnectionAdapters :: Column>的未定义方法'type_cast' （NoMethodError） [英] undefined method `type_cast' for #<ActiveRecord::ConnectionAdapters::Column> (NoMethodError)

问题描述

ActiveRecord :: ConnectionAdapters :: Column 以前有一个名为 type_cast 的方法，该方法接收了一个字符串并将其强制转换到适当的情况。

这里是使用它的代码： p>

 ＃创建一个负责类型转换的列
 @column = ActiveRecord :: ConnectionAdapters :: Column.new（attribute .to_s，options [：default]，@type =='any'？nil：@type）
 
＃根据定义的首选项类型强制转换值
 def type_cast（ value）
 if @type =='any'
 value 
 else 
 @ column.type_cast（value）
 end 
 end 
  

我正在使用Rails / ActiveRecord 4.2.10。

这里有一个列表： typecast替代方法，但是到目前为止，它并不是特别有用据我所知。

ETA：目前，我已经从原始的type_cast复制了代码，并对其进行了修改。 o在本地使用。

解决方案

ActiveRecord :: ConnectionAdapters ::列#type_cast 已被删除/移动到API的其他部分，包括 type_cast_for_database 或 type_cast_for_schema 。

您可以在连接上使用 type_cast ，例如：

  @column = ActiveRecord :: ConnectionAdapters :: Column.new（attribute.to_s，options [：default]，@type =='any'吗？ nil：@type）
 
＃根据定义的首选项类型转换值
 def type_cast（value）
如果@type =='any'
值
否则
 ActiveRecord :: Base.connection.type_cast（value，@column）＃< ----这里
结束
结束
  

您可以在 _ type_cast 和 type_cast 。。 p>

ActiveRecord::ConnectionAdapters::Column used to have a method called type_cast which took a string and cast it "to an appropriate instance". This appears to have been removed at some point, and I can't figure out what I should do to replace it.

Here is the code that uses it:

  # Create a column that will be responsible for typecasting
  @column = ActiveRecord::ConnectionAdapters::Column.new(attribute.to_s, options[:default], @type == 'any' ? nil : @type)

  # Typecasts the value based on the type of preference that was defined
  def type_cast(value)
    if @type == 'any'
      value
    else
      @column.type_cast(value)
    end
  end

I'm using Rails/ActiveRecord 4.2.10.

There's a list here: typecast alternatives, but it's not particularly useful, so far as I can tell.

ETA: For now, I've copied the code from the original type_cast and modified it to use it locally. But if there's a real solution, I'd prefer that.

解决方案

ActiveRecord::ConnectionAdapters::Column#type_cast was removed / moved to other parts of the API, including things like type_cast_for_database or type_cast_for_schema.

You can use the type_cast on the connection though, like this:

@column = ActiveRecord::ConnectionAdapters::Column.new(attribute.to_s, options[:default], @type == 'any' ? nil : @type)

# Typecasts the value based on the type of preference that was defined
def type_cast(value)
  if @type == 'any'
    value
  else
    ActiveRecord::Base.connection.type_cast(value, @column) # <---- HERE
  end
end

You can dig in the internals at _type_cast and type_cast if you are curious.

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