我应该如何在ruby中使用递归方法

我使用Mechanize编写了一个简单的web涂鸦程序，现在我陷入了如何递归获取下一页的困境，下面是代码

def self.generate_page  #generate a Mechainze page object,the first page
    agent = Mechanize.new
    url = "http://www.baidu.com/s?wd=intitle:#{URI.encode(WORD)}%20site:sina.com.cn&rn=50&gpc=stf#{URI.encode(TIME)}"
     page = agent.get(url)
     page  
end

def self.next_page(n_page)  #get next page recursively by click   next tag showed in each pages
 puts n_page   
# if I dont use puts , I get nothing , when using puts, I get 
#<Mechanize::Page:0x007fd341c70fd0>
#<Mechanize::Page:0x007fd342f2ce08>
#<Mechanize::Page:0x007fd341d0cf70>
#<Mechanize::Page:0x007fd3424ff5c0>
#<Mechanize::Page:0x007fd341e1f660>
#<Mechanize::Page:0x007fd3425ec618>
#<Mechanize::Page:0x007fd3433f3e28>
#<Mechanize::Page:0x007fd3433a2410>
#<Mechanize::Page:0x007fd342446ca0>
#<Mechanize::Page:0x007fd343462490>
#<Mechanize::Page:0x007fd341c2fe18>
#<Mechanize::Page:0x007fd342d18040>
#<Mechanize::Page:0x007fd3432c76a8>  
#which are the results I want

    np = Mechanize.new.click(n_page.link_with(:text=>/next/)) unless n_page.link_with(:text=>/next/).nil?
     result = next_page(np) unless np.nil?
     result    # here the value is empty, I dont know what is worng
end

def  self.get_page  # trying to pass the result of next_page() method 
    puts  next_page(generate_page)
    # it seems result is never passed here, 
end

def self.generate#页面#生成一个Mechanize页面对象，第一个页面
agent=Mechanize.new
url=”http://www.baidu.com/s?wd=intitle:#{URI.encode（WORD）}%20site:sina.com.cn&rn=50&gpc=stf{URI.encode（TIME）}”
page=agent.get（url）
页
结束
定义self.next_page（n_page）#通过单击每个页面中显示的next标记递归获取下一页
放n_页
#如果我不使用看跌期权，我将一无所获，当我使用看跌期权时，我将一无所获
#
#
#
#
#
#
#
#
#
#
#
#
#  
#我想要的结果是什么
np=Mechanize.new。单击（n_page.link_with（：text=>/next/）除非n_page.link_with（：text=>/next/）。nil？
结果=下一页（np），除非np.nil？
结果#这里的值是空的，我不知道是什么
结束
def self.get_page#尝试传递next_page（）方法的结果
放置下一个页面（生成页面）
#结果似乎从未在这里传递过，
结束

我遵循这两个链接 及

---

但还是不知道怎么回事。。希望有人能帮我。。谢谢

您的代码有一些问题：

您不应该多次调用

Mechanize.new

从风格的角度来看，你做了太多的零检查 除非您对递归有偏好，否则以迭代方式进行可能会更容易

要让

next_page

方法返回包含链中每个链接页的数组，可以编写以下代码：

# you should store the mechanize agent as a global variable
Agent = Mechanize.new

# a helper method to DRY up the code
def click_to_next_page(page)
  Agent.click(n_page.link_with(:text=>/next/))
end

# repeatedly visits next page until none exists
# returns all seen pages as an array
def get_all_next_pages(n_page)
   results = []
   np = click_to_next_page(n_page)
   results.push(np)
   until !np
     np = click_to_next_page(np)
     np && results.push(np)
   end
   results
end

# testing it out (i'm not actually running this)
base_url = "http://www.baidu.com/s?wd=intitle:#{URI.encode(WORD)}%20site:sina.com.cn&rn=50&gpc=stf#{URI.encode(TIME)}"
root_page = Agent.get(base_url)
next_pages = get_all_next_pages(root_page)
puts next_pages

---

您的代码存在一些问题：

您不应该多次调用

Mechanize.new

从风格的角度来看，你做了太多的零检查 除非您对递归有偏好，否则以迭代方式进行可能会更容易

要让

next_page

方法返回包含链中每个链接页的数组，可以编写以下代码：

# you should store the mechanize agent as a global variable
Agent = Mechanize.new

# a helper method to DRY up the code
def click_to_next_page(page)
  Agent.click(n_page.link_with(:text=>/next/))
end

# repeatedly visits next page until none exists
# returns all seen pages as an array
def get_all_next_pages(n_page)
   results = []
   np = click_to_next_page(n_page)
   results.push(np)
   until !np
     np = click_to_next_page(np)
     np && results.push(np)
   end
   results
end

# testing it out (i'm not actually running this)
base_url = "http://www.baidu.com/s?wd=intitle:#{URI.encode(WORD)}%20site:sina.com.cn&rn=50&gpc=stf#{URI.encode(TIME)}"
root_page = Agent.get(base_url)
next_pages = get_all_next_pages(root_page)
puts next_pages

---

谢谢起初，我打算迭代执行，但在以下几行失败：

results.push（np）until！np np=点击下一页（np）np&&results.push（np）

你的代码真的帮了我很多忙！谢谢起初，我打算迭代执行，但在以下几行失败：

results.push（np）until！np np=点击下一页（np）np&&results.push（np）

你的代码真的帮了我很多忙！