Need help returning

I am building a small application in RoR that has a form asking for a URL. Once the URL has been filled in and submit button is pressed I have downloaded a web-scraping plugin scrAPI(which is working fine) which gets the of URL and creates a record in db with title.

My issue right now is that I am able to make the whole thing work if the URL is valid and scrAPI is able to process it. If a URL entered does not work it gives this "Scraper::Reader::HTTPInvalidURLError" which is expected, but my knowledge of working in Model is preventing me from handing that error in a correct manner.

Controller:

#controller
class ArticleController < ApplicationController

  def savearticle

    @newarticle = params[:newarticle]

    @link = @newarticle["link"]
    @id   = @newarticle["id"]
    Article.getlink(@link)

    success = Article.find(:last).update_attributes( params[:newarticle] )

    if success
      render :partial => 'home/articlesuccess'
    else 
      render :partial => 'home/articlebad'
    end

  end


end

# model
require 'scrapi'

class Article < ActiveRecord::Base

  attr_accessor :getlink

  def self.getlink(link)

    scraper = Scraper.define do
      process "title", :title => :text
      result :title
    end  

    uri = URI.parse(link)

    Article.create(:title => scraper.scrape(uri))

  end


end

How to:

1) Handle the Scraper::Reader::HTTPInvalidURLError properly, so text could be returned to view with proper error.

2) I would also like to know how I can return 'uri' from model and use it in the controller or view.

3) Also, I would like to return the ID of the Article created in开发者_C百科 Model so I can use that in the controller instead of doing find(:last) which seems like bad practice.

Something like...

class ApplicationController < ActionController::Base
  rescue_from 'Scraper::Reader::HTTPInvalidURLError', :with => :invalid_scrape_url


 private
   def invalid_scrape_url
      flash[:error] = 'The URL for scraping is invalid.'
      render :template => 'pages/invalid_scrape_url'
   end
end

rescue_from is what you need.

That's 1)

for 2) You could just use @uri but personally I'd create a new model called Scrape and then you can retrieve each Scrape that is attempted.

for 3) I'm not quite sure of the question but

@article = Article.create(:title => scraper.scrape(uri))

then @article.id

Hope that helps!

(1) In Ruby, you can handle any exception as follows:

begin
  # Code that may throw an exception
rescue Scraper::Reader::HTTPInvalidURLError
  # Code to execute if Scraper::Reader::HTTPInvalidURLError is raised
rescue
  # Code to execute if any other exception is raised
end

So you could check for this in your controller as follows:

begin
  Article.getlink(@link)
  # all your other code
rescue Scraper::Reader::HTTPInvalidURLError
  render :text => "Invalid URI, says scrAPI"
rescue
  render :text => "Something else horrible happened!"
end

You'll need to require 'scrapi' in your controller to have access Scraper::Reader::HTTPInvalidURLError constant.

I would probably make the creation of the new Article and the call to scrAPI's method separate:

title = scraper.scrape(uri)
Article.create(:title => title)

(2) and (3) In Ruby, the last statement of a method is always the return value of that method. So, in your self.getlink method, the return value is the newly created Article object. You could get the ID like this in your controller:

article = Article.getlink(@link)
article_id = article.id

You may need to refactor the code a bit to get the results you want (and make the code sample on the whole cleaner).