How to manipulate DOM with Ruby on Rails

Question

As the title said, I have some DOM manipulation tasks. For example, I want to: - find all H1 element which have blue color. - find all text which have size 12px. - etc..

Answer 1

If what you're trying to do is manipulate HTML documents inside a rails application, you should take a look at Nokogiri.

It uses XPath to search through the document. With the following, you would find any h1 with the "blue" css class inside a document.

require 'nokogiri'
require 'open-uri'

doc = Nokogiri::HTML(open('http://www.stackoverflow.com'))
doc.xpath('//h1/a[@class="blue"]').each do |link|
    puts link.content
end

After, if what you were trying to do was indeed parse the current page dom, you should take a look at JavaScript and JQuery. Rails can't do that.