如何添加到序列化数组 [英] How to add to a serialized array

问题描述

我有一个现有用户，它有一个序列化字段，我希望能够将最近的消息添加到数组/序列化字段中.

I have an existing user which has a serialized field and I want to be able to add recent messages to the array / serialized field.

class User < ActiveRecord::Base
 serialize :recent_messages
end

在我尝试过的控制器中

@user = current_user
@user.recent_messages << params[:message]
@user.save

但我收到以下错误:

NoMethodError (undefined method `<<' for nil:NilClass):

在我的架构中，我有:

create_table "users", :force => true do |t|
    t.text     "recent_messages"
  end

对我哪里出错有什么想法吗?

Any ideas on where I'm going wrong?

推荐答案

您可以将类传递给 序列化:

You can pass a class to serialize:

class User < ActiveRecord::Base
  serialize :recent_messages, Array
end

以上确保 recent_messages 是一个 Array:

The above ensures that recent_messages is an Array:

User.new
#=> #<User id: nil, recent_messages: [], created_at: nil, updated_at: nil>

请注意，如果类型不匹配，您可能需要转换现有字段.

Note that you might have to convert existing fields if the types don't match.

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