Class: LinkPreviewGenerator

Inherits:
Object
  • Object
show all
Defined in:
lib/link_preview_generator.rb

Class Method Summary collapse

Class Method Details

.get_html_elements(html) ⇒ Object 



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# File 'lib/link_preview_generator.rb', line 64

def self.get_html_elements(html)
  elements = {}
  #parse the html 
  resp = Nokogiri::HTML(html)
  #fetch title
  elements[:title] = !(resp.css("meta [property='og:title']").empty?) ? resp.css("meta [property='og:title']")[0]["content"] : (!(resp.css("title").empty?) ? resp.css("title")[0].children[0].content : "" )

  #fetch description
  elements[:description] = !(resp.css("meta [property='og:description']").empty?) ? resp.css("meta [property='og:description']")[0]["content"] : ""

  #fetch image
  elements[:image_url] = !(resp.css("meta [property='og:image']").empty?) ? resp.css("meta [property='og:image']")[0]["content"] : ""

  #fetch type
  elements[:link_type] = !(resp.css("meta [property='og:type']").empty?) ? resp.css("meta [property='og:type']")[0]["content"] : ""

  #if type is video feth the video link
  elements[:video_url] = (elements[:link_type] == "video") ? resp.css("meta [property='og:url']")[0]["content"] : ""

  return elements
end

.get_preview_elements(url) ⇒ Object 



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# File 'lib/link_preview_generator.rb', line 7

def self.get_preview_elements(url)
  link_elements = nil
  
  # generate a html get request to the link
  begin
    html_body = self.html_get_req(url) 
  rescue Exception => e
    puts "ERROR getting link preview : "+e.message
    return nil
  end 
  
  #parse the html body and retrieve the preiview elements
  if html_body != nil
    link_elements = self.get_html_elements(html_body) 
    return link_elements
  else
    return nil
  end 

end

.html_get_req(url) ⇒ Object 



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# File 'lib/link_preview_generator.rb', line 28

def self.html_get_req(url)

  ishttps = false
  host = 80

  # if the link does not containt http or https then add
  if (/^https:\/\//.match(url)) 
    host = 443
    ishttps = true
  elsif (/^http:\/\//.match(url))
    # do nothing
  else
    url = "http://"+url
  end
  
  uri = URI.parse(url);
  http = Net::HTTP.new(uri.host, host)

  #if https link enable ssl
  if ishttps
    http.use_ssl = true
    http.verify_mode = OpenSSL::SSL::VERIFY_NONE
  end
  
  #Http request
  request = Net::HTTP::Get.new(uri.request_uri)   
  response = http.request(request)
  
  if response.code == "200"
    return response.body
  else
    return nil
  end 

end