Forum: Ruby on Rails JSON::ParserError in controller

Posted by Anush J. (anush_j)
on 2013-01-07 10:01
Hi All
I'm trying to build an application which requires to scrap information
from a webpage. On trying to perform the action, I get an error while
trying to convert the html data to JSON. Has anyone experienced this
before and if so can you please tell me how to solve this problem ?
Please see below for code snippet and error log.

Thanks in advance
Anush

require 'net/http'
require 'open-uri'
require 'uri'
require 'json'
require 'pp'

class Merchant < ActiveRecord::Base

  def self.grab_original_content
    ## EXAMPLE USING ZED451.COM
    uri = URI("http://www.zed451.com")
    response = Net::HTTP.get_response(uri)
    @hash = JSON(response.body)
    puts "#{@hash}"
  end

end

I call the above method in my controller and send @hash to view.
In my browser I see the below error:

JSON::ParserError in Original contentController#index

706: unexpected token at '<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0
Transitional//EN"
  "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitiona...

And the rest of the page is printed without error in html format.
Posted by Jordon Bedwell (Guest)
on 2013-01-07 12:27
(Received via mailing list)
Hai,

On Mon, Jan 7, 2013 at 3:01 AM, Anush J. <lists@ruby-forum.com> wrote:
I call the above method in my controller and send @hash to view.
In my browser I see the below error:

JSON::ParserError in Original contentController#index

706: unexpected token at 'Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitiona...

And the rest of the page is printed without error in html format.

It's printed out as HTML because it is HTML. HTML is not JSON and vice 
verse. If you wish to parse the page as it is you need to use something 
like Nokogiri so it gets tokenized, if you expected JSON you should 
contact them and ask them what went wrong.

---

Jordon Bedwell
http://envygeeks.com/
https://twitter.com/envygeeks
Posted by Anush J. (anush_j)
on 2013-01-07 20:03
Hi Jordon,
Thanks for your response.
I thought the JSON(response.body) performs the conversion of HTML->JSON.
But I also tried response.body.to_json which gave me the same error.
Will be great if you can explain a bit. Mean while I will also try using
nokigiri.

Thanks
Anush

Jordon Bedwell wrote in post #1091317:
> Hai,
>
> On Mon, Jan 7, 2013 at 3:01 AM, Anush J. <lists@ruby-forum.com> wrote:
> I call the above method in my controller and send @hash to view.
> In my browser I see the below error:
>
> JSON::ParserError in Original contentController#index
>
> 706: unexpected token at 'Transitional//EN"
> "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitiona...
>
> And the rest of the page is printed without error in html format.
>
> It's printed out as HTML because it is HTML. HTML is not JSON and vice
> verse. If you wish to parse the page as it is you need to use something
> like Nokogiri so it gets tokenized, if you expected JSON you should
> contact them and ask them what went wrong.
>
> ---
>
> Jordon Bedwell
> http://envygeeks.com/
> https://twitter.com/envygeeks
Posted by Dheeraj Kumar (Guest)
on 2013-01-07 20:10
(Received via mailing list)
You cannot convert HTML to JSON and vice versa. HTML is a markup 
language, while JSON is a data interchange format.

You need to parse your HTML with Nokogiri or Hpricot, extract whatever 
data you want from it and put it in a Hash, then call .to_json on it to 
get the JSON response.

--
Dheeraj Kumar
Posted by Anush J. (anush_j)
on 2013-01-07 20:12
Dheeraj Kumar wrote in post #1091355:
> You cannot convert HTML to JSON and vice versa. HTML is a markup
> language, while JSON is a data interchange format.
>
> You need to parse your HTML with Nokogiri or Hpricot, extract whatever
> data you want from it and put it in a Hash, then call .to_json on it to
> get the JSON response.
>
> --
> Dheeraj Kumar

Hi Dheeraj,
Ahh..I see. Got it now. Thanks, helps a lot in understanding.

Thanks
Anush
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