如何在 Ruby 哈希上深度转换值

Question

我有一个如下所示的哈希：

hash = {
  'key1' => ['value'],
  'key2' => {
    'sub1' => ['string'],
    'sub2' => ['string'],
  },
  'shippingInfo' => {
                   'shippingType' => ['Calculated'],
                'shipToLocations' => ['Worldwide'],
              'expeditedShipping' => ['false'],
        'oneDayShippingAvailable' => ['false'],
                   'handlingTime' => ['3'],
    }
  }

我需要将每个值转换为数组中的单个字符串，以使其最终如下所示：

hash = {
  'key1' =>  'value' ,
  'key2' => {
    'sub1' => 'string' ,
    'sub2' => 'string' ,
  },
  'shippingInfo' => {
                   'shippingType' => 'Calculated' ,
                'shipToLocations' => 'Worldwide' ,
              'expeditedShipping' => 'false' ,
        'oneDayShippingAvailable' => 'false' ,
                   'handlingTime' => '3' ,
    }
  }

我找到了这个，但无法让它工作 https://gist.github.com/chris/b4138603a8fe17e073c6bc073eb17785

Answer 1

我注意到很多答案都带有不必要的递归。当前版本的带有 ActiveSupport 的 Ruby 2.7.x（我用 6.1.4.4 测试过）将允许您这样做：

输入数据：

hash = {
  'key1' => ['value'],
  'key2' => {
    'sub1' => ['string'],
    'sub2' => ['string']},
  'shippingInfo' => {
    'shippingType' => ['Calculated'],
    'shipToLocations' => ['Worldwide', 'Web'],
    'expeditedShipping' => ['false'],
    'oneDayShippingAvailable' => ['false'],
    'handlingTime' => ['3']}}

解决方案：

hash.deep_transform_values do |value|
  # whatever you need to do to any nested value, like:
  if value == value.to_i.to_s
    value.to_i
  else
    value
  end
end

上面的例子会返回一个类型转换的 String 到 Integer。

Answer 2

hash = {
  'key1' => ['value'],
  'key2' => {
    'sub1' => ['string'],
    'sub2' => ['string'],
  },
  'shippingInfo' => {
                   'shippingType' => ['Calculated'],
                'shipToLocations' => ['Worldwide', 'Web'],
              'expeditedShipping' => ['false'],
        'oneDayShippingAvailable' => ['false'],
                   'handlingTime' => ['3'],
    }
  }

def recurse(hash)
  hash.transform_values do |v|
    case v
    when Array
      v.size == 1 ? v.first : v
    when Hash
      recurse v
    else
      # raise exception
    end
  end
end

recurse hash
  #=> {"key1"=>"value",
  #    "key2"=>{
  #      "sub1"=>"string",
  #      "sub2"=>"string"
  #    },
  #    "shippingInfo"=>{
  #      "shippingType"=>"Calculated",
  #      "shipToLocations"=>["Worldwide", "Web"],
  #      "expeditedShipping"=>"false",
  #      "oneDayShippingAvailable"=>"false",
  #      "handlingTime"=>"3"
  #    }
  #  } 

Answer 3

作为替代方案，考虑使用一个对象并允许初始化器为您解构一些键。

很多像我这样的人开始使用 Ruby 来支持 Perl 的原因之一是因为可以更好地表达对象，而不是像数组和散列这样的原语。充分利用它！

class ShippingStuff # You've kept the data vague

  def initialize key1:, key2:, shippingInfo:
    @blk = -> val {
      val.respond_to?(:push) && val.size == 1 ?
          val.first :
          cleankeys(val)
    }
    @key1 = cleankeys key1
    @key2 = cleankeys key2
    @shippingInfo = shippingInfo
  end

  attr_reader :key1, :key2, :shippingInfo

  # basically a cut down version of what
  # Sebastian Palma answered with
  def cleankeys data
    if data.respond_to? :transform_values
      data.transform_values &@blk
    else
      @blk.call(data)
    end
  end

end


hash = {
  'key1' => ['value'],
  'key2' => {
    'sub1' => ['string'],
    'sub2' => ['string'],
  },
  'shippingInfo' => {
                   'shippingType' => ['Calculated'],
                'shipToLocations' => ['Worldwide'],
              'expeditedShipping' => ['false'],
        'oneDayShippingAvailable' => ['false'],
                   'handlingTime' => ['3'],
  }
}

shipper = ShippingStuff.new hash.transform_keys!(&:to_sym)
shipper.key1
# "value"
shipper.key2
# {"sub1"=>"string", "sub2"=>"string"}
shipper.shippingInfo
# {"shippingType"=>["Calculated"], "shipToLocations"=>["Worldwide"], "expeditedShipping"=>["false"], "oneDayShippingAvailable"=>["false"], "handlingTime"=>["3"]}

同样，我什至会为 shippingInfo 数据创建一个 Info 类。

如果key1 和key2 是动态的，您可能会遇到不同的问题，但也有解决办法（double splat 就是其中之一）。

Answer 4

类似的东西呢：

def deep_transform_values(hash)
  return hash unless hash.is_a?(Hash)

  hash.transform_values do |val|
    if val.is_a?(Array) && val.length == 1
      val.first
    else
      deep_transform_values(val)
    end
  end
end

用类似的东西测试过：

hash = {
  'key1' => ['value'],
  'key2' => {
    'sub1' => ['string'],
    'sub2' => ['string'],
  },
  'shippingInfo' => {
                   'shippingType' => ['Calculated'],
                'shipToLocations' => ['Worldwide'],
              'expeditedShipping' => ['false'],
        'oneDayShippingAvailable' => ['false'],
                   'handlingTime' => ['3'],
                   'an_integer' => 1,
                   'an_empty_array' => [],
                   'an_array_with_more_than_one_elements' => [1,2],
                   'a_symbol' => :symbol,
                   'a_string' => 'string'
    }
  }

给予：

{
  "key1"=>"value",
  "key2"=>{
    "sub1"=>"string",
    "sub2"=>"string"
  },
  "shippingInfo"=> {
    "shippingType"=>"Calculated",
    "shipToLocations"=>"Worldwide",
    "expeditedShipping"=>"false",
    "oneDayShippingAvailable"=>"false",
    "handlingTime"=>"3",
    "an_integer"=>1,
    "an_empty_array"=>[],
    "an_array_with_more_than_one_elements"=>[1, 2],
    "a_symbol"=>:symbol,
    "a_string"=>"string"
  }
}

---

根据您在 cmets 中的问题，我想逻辑会有所改变：

class Hash
  def deep_transform_values
    self.transform_values do |val|
      next(val.first) if val.is_a?(Array) && val.length == 1
      next(val) unless val.respond_to?(:deep_transform_values)

      val.deep_transform_values
    end
  end
end