ruby-on-rails - 加载用于在 Rails 中解析的网页

Question

假设，我想从 Web 获取一个页面到我的应用程序并对其进行某种解析。我怎么做？我应该从哪里开始？应该需要一些插件/ gem 吗？您在解决此类任务时通常的做法是什么？

Answer 1

你应该尝试像 Hpricot 这样的 Gems ( wiki ) 或 Nokogiri .

杏示例:

require 'open-uri'
require 'rubygems'
require 'hpricot'

html = Hpricot(open(an_url).read)
# This would search for any images inside a paragraph (XPath)
html.search('/html/body//p//img')
# This would search for any images with the class "test" (CSS selector)
html.search('img.test')

Nokogiri 示例:

require 'open-uri'
require 'rubygems'
require 'hpricot'

html = Nokogiri::HTML(open(an_url).read)
# This would search for any images inside a paragraph (XPath)
html.xpath('/html/body//p//img')
# This would search for any images with the class "test" (CSS selector)
html.css('img.test')

Nokogiri通常更快。这两个库都具有很多功能。