Rails:序列化值为逗号分隔，而不是YAML。

I'm looking for a way to store a serialized value of eg. IDs in a column. In before claims that this is not an optimal design: the column is used for IDs of associated records, but will only be used when displaying the record - so no queries are made with selection on the column and no joins will be made on this column either.

我正在寻找一种方法来存储eg的序列化值。id列。在声明这不是最优设计之前:该列用于相关记录的id，但仅在显示记录时使用——因此不会对列上的选择进行查询，也不会对该列进行连接。

In Rails I can serialize the column by using:

在Rails中，我可以使用:

class Activity
   serialize :data
end

This encodes the column as YAML. For legacy sake and since I'm only storing one dimensional arrays containing only integers, I find it more suitable to store it as a comma-separated value.

这将列编码为YAML。为了传统的缘故，因为我只存储一个只包含整数的一维数组，所以我觉得它更适合作为逗号分隔的值存储。

I've successfully implemented basic accessors like this:

我已经成功地实现了这样的基本访问器:

def data=(ids)
    ids = ids.join(",") if ids.is_a?(Array)
    write_attribute(:data, ids)
end

def data
    (read_attribute(:data) || "").split(",")
end

This works pretty fine. However I'd like to add array-like methods to this attribute:

这工作很好。但是我想在这个属性中加入arraylike方法:

activity = Activity.first
activity.data << 42
...

How would I do this?

我该怎么做呢?

2 个解决方案

#1

You can do it with composed_of feature as explained in this post. It should be something like:

您可以使用本文所解释的composed_of特性来实现它。应该是这样的:

  composed_of :data, :class_name => 'Array', :mapping => %w(data to_csv),
                   :constructor => Proc.new {|column| column.to_csv},
                   :converter   => Proc.new {|column| column.to_csv}

  after_validation do |u|
    u.data = u.data if u.data.dirty? # Force to serialize
  end

Haven't tested it though.

没有测试过。

#2

You can use serialize with a custom coder in rails 3.1.

您可以使用rails 3.1中的自定义编码器进行序列化。

See my answer to this question. :-)

请看我对这个问题的回答。:-)

#1