修改下面的方法，让我只调用一次Nokogiri::HTML？

Question

下面的代码删除了站点的不同部分。基本上，我对每个部分都有几个方法，然后是一个方法(parse_details)，它将所有散列合并为一个散列：

class Parser
  def parse_details(html)
    merged_hashes = {}
    array_of_hashes = [
      self.parse_department(html),
      self.parse_super_saver(html),
    ]
    array_of_hashes.inject(merged_hashes,:update)

    return merged_hashes
  end

  def parse_department(file)  
    html       = file
    data       = Nokogiri::HTML(open(html))
    department = data.css('#ref_2619534011')

    @department_hash = {}
    department.css('li').drop(1).each do | department |
      department_title = department.css('.refinementLink').text
      department_count = department.css('.narrowValue').text[/[\d,]+/].delete(",").to_i
      @department_hash[:department] ||= {}
      @department_hash[:department]["Pet Supplies"] ||= {}
      @department_hash[:department]["Pet Supplies"][department_title] = department_count
    end 

    return @department_hash
  end 

  def parse_super_saver(file)
    html        = file
    data        = Nokogiri::HTML(open(html))
    super_saver = data.css('#ref_2661623011')

    @super_saver_hash = {}
    super_saver.css('li').each do | super_saver |
      super_saver_title = super_saver.css('.refinementLink').text
      super_saver_count = super_saver.css('.narrowValue').text[/[\d,]+/].delete(",").to_i
      @super_saver_hash[:super_saver] ||= {}
      @super_saver_hash[:super_saver][super_saver_title] = super_saver_count
    end 

    return @super_saver_hash
  end

如您所见，我不止一次调用Nokogiri::HTML(open(html))。

有人建议我这样做：

  def self.parse(html)
    doc = Nokogiri::HTML html 
    self.parse_details(doc) unless doc.nil?
  end

所以我只调用Nokogiri::HTML一次。

但是我被困住了，例如，我不知道如何处理像department = data.css('#ref_2619534011')这样的部分，它们是否应该进入新的parse方法？我也不知道如何处理html和file参数。有了新的parse方法后，我应该保留它们还是删除它们？

有什么建议可以让我完成我想要的东西吗？

Answer 1

class Parser
  def initialize(url)
    @data = Nokogiri.HTML(open(url))
  end
  def parse_details()
    {}.tap do |merged_hashes|
      array_of_hashes = [
        parse_department(),
        parse_super_saver(),
      ]
      array_of_hashes.inject(merged_hashes,:update)
    end
  end

  def parse_department()  
    department = @data.css('#ref_2619534011')

    @department_hash = {}
    department.css('li').drop(1).each do | department |
      department_title = department.css('.refinementLink').text
      department_count = department.css('.narrowValue').text[/[\d,]+/].delete(",").to_i
      @department_hash[:department] ||= {}
      @department_hash[:department]["Pet Supplies"] ||= {}
      @department_hash[:department]["Pet Supplies"][department_title] = department_count
    end 
    @department_hash
  end 

  def parse_super_saver()
    super_saver = @data.css('#ref_2661623011')

    @super_saver_hash = {}
    super_saver.css('li').each do | super_saver |
      super_saver_title = super_saver.css('.refinementLink').text
      super_saver_count = super_saver.css('.narrowValue').text[/[\d,]+/].delete(",").to_i
      @super_saver_hash[:super_saver] ||= {}
      @super_saver_hash[:super_saver][super_saver_title] = super_saver_count
    end 
    @super_saver_hash
  end
end

如果您实际上不需要@department_hash和@super_saver_hash作为实例变量，则可以选择将它们转换为我在parse_details中使用的tap样式。

如果你实际上根本不需要它是一个类，而仅仅是一个方法的集合，那么考虑一下：

module Parser
  def self.parse_details(url)
    data = Nokogiri.HTML(open(url))
    {}.tap do |merged_hashes|
      array_of_hashes = [
        parse_department(data),
        parse_super_saver(data),
      ]
      array_of_hashes.inject(merged_hashes,:update)
    end
  end

  def self.parse_department(data)
    {}.tap do |department_hash|
      data.css('#ref_2619534011 li').drop(1).each do | department |
        department_title = department.css('.refinementLink').text
        department_count = department.css('.narrowValue').text[/[\d,]+/].delete(",").to_i
        department_hash[:department] ||= {}
        department_hash[:department]["Pet Supplies"] ||= {}
        department_hash[:department]["Pet Supplies"][department_title] = department_count
      end
    end
  end 

  def self.parse_super_saver(data)    
    {}.tap do |super_saver_hash|
      data.css('#ref_2661623011 li').each do |super_saver|
        super_saver_title = super_saver.css('.refinementLink').text
        super_saver_count = super_saver.css('.narrowValue').text[/[\d,]+/].delete(",").to_i
        super_saver_hash[:super_saver] ||= {}
        super_saver_hash[:super_saver][super_saver_title] = super_saver_count
      end 
    end
  end