Ruby send(attribute.to_sym) 用于 Rails 方法 [英] Ruby send(attribute.to_sym) for Rails Method

问题描述

我使用的是 Ruby 1.9.2，需要检查表的所有值以确保所有内容都采用 UTF-8 编码.有很多列，所以我希望能够使用 column_names 方法遍历所有列并将值编码为 UTF-8.我认为这可能有效:

I'm using Ruby 1.9.2 and need to go through all of the values for a table to make sure everything is in UTF-8 encoding. There are a lot of columns so I was hoping to be able to use the column_names method to loop through them all and encode the values to UTF-8. I thought this might work:

def self.make_utf
  for listing in Listing.all
    for column in Listing.column_names
      column_value_utf = listing.send(column.to_sym).encode('UTF-8')
      listing.send(column.to_sym) = column_value_utf
    end
    listing.save
  end

  return "Updated columns to UTF-8"

end

但它返回一个错误:

syntax error, unexpected '=', expecting keyword_end
        listing.send(column.to_sym) = column_value_utf

我不知道如何使其正常工作.

I can't figure out how to make this work correctly.

推荐答案

您正在使用 send 错误，并且您发送了错误的符号来表示您想要执行的操作:

You're using send wrong and you're sending the wrong symbol for what you want to do:

listing.send(column + '=', column_value_utf)

您正在尝试使用 column_value_utf 作为参数调用 x= 方法(对于某些 x)，这就是 ox = column_value_utf 通常会这样做.因此，您需要构建正确的方法名称(只需一个字符串即可)，然后将该方法的参数作为参数发送到 send.

You're trying to call the x= method (for some x) with column_value_utf as an argument, that's what o.x = column_value_utf would normally do. So you need to build the right method name (just a string will do) and then send the arguments for that method in as arguments to send.

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