Nokogiri - Encoding Issue - Invalid UTF8 characters - ruby

Can someone take a look at this. I think there is invalid UTF-8 characters when making this call.
Nokogiri::HTML(open("http://www.next.co.uk/x502062s2"))
If there a way around this? And is this the issue? I am writing a new open source screen scraper designed for product information capture (when a site does not supply a feed) before anyone says I am doing something a little shifty :-)

Before passing anything to Nokogiri, you can encode the content of the page, and ignore all invalid UTF characters using Iconv.
I was using it like this:
ic = Iconv.new('UTF-8//IGNORE', 'UTF-8')
valid_string = ic.iconv(open('http://example.com').read)
You can also check "Fixing invalid UTF-8 in Ruby, revisited."

Related

How to handle the javascript decoding error?

When the code is implemented, some characters cannot be decoded. I am getting a bunch of question marks like ??. How can I fix this?
HtmlInput inputBox2 = (HtmlInput)currentPage.getHtmlElementById("classNo");
inputBox2.setValueAttribute("2016同學15");
ScriptResult result = currentPage.executeJavaScript("javascript:Search(2)");
I found this in the compiler: ScriptResult[result=net.sourceforge.htmlunit.corejs.javascript.Undefined#24d7aac3 page=HtmlPage(http://www.xx.org/classNo=2016??15)#1330510442]
You might try to use URL-encoding for some ASCII and all non ASCII characters.
e.g. space by %20
Here is a web site explaning the
HTML URL Encoding Reference.
You can also interactive encode strings there.
Your "2016同學15" would be encoded as:
"2016%E5%90%8C%E5%AD%B815"

Ruby character encoding issue with scraped HTML

I'm having a character encoding issue with a Ruby script that does some HTML scraping and parsing with the Nokogiri gem. At one point in the script, I call join("\n") on an array of strings that have been pulled from some HTML, which causes this error:
./script.rb:333:in `join': incompatible character encodings: UTF-8 and ASCII-8BIT (Encoding::CompatibilityError)
In my logs, I can see Café showing up for some of the strings that would be included in the join operation.
Is it that some of the strings in my array to be joined are ASCII-8BIT and some are UTF-8 and ruby can't combine them? Do I need to convert or sanitize my strings after parsing them with Nokogiri (into UTF-8)?.
I tried force_encoding('UTF-8') and encode('UTF-8') on the scraped HTML content before I do anything else with it, but it didn't help. In fact, after I tried encode('UTF-8'), my script crashed even earlier when it called to_s on a string containing Café.
Character encoding always really confuses me. Is there something else I can do to sanitize the strings to avoid this error?
Edit:
I was doing something similar in Perl recently and used a module called Text::Unidecode and was able to pass my strings to a function that translates any problematic characters e.g. the letter a with an acute to the plain letter a. Is there anything similar for ruby? (This isn't necessarily what I'm aiming for though, if I can keep the a with acute then that's preferable I think.
Edit2:
I'm really confused by this and it's proving difficult to reproduce reliably. Here's some code:
[CODE REMOVED]
Edit3:
I removed the previously posted code example because it wasn't correct. But the bottom line is, whenever I try to print or call to_s on the string that was scraped, I get the encoding error.
Edit4:
It turned out in the end that the scraped html input was not what was causing the problem. I got the encoding error whenever I tried to print or call to_s on a hash containing, among other things, the scraped html text. The 'other things' were values from database queries, and they were being returned in ASCII-8BIT. To fix the issue, I explicitly had to call force_encoding('UTF-8') on each database value that I use (although I hear that the mysql2 gem does this automatically so I should switch to that).
I hate character encoding.
Presumably, Café is supposed to be Café. If we start out with Café in UTF-8 but treat the bytes as though they were encoded in ISO-8859-1 (AKA Latin-1) and then re-encode them as UTF-8, we get the Café that you're seeing; for example:
> s = 'Café'
=> "Café"
> s.encoding
=> #<Encoding:UTF-8>
> s.force_encoding('iso-8859-1').encode('utf-8')
=> "Café"
So somewhere you're reading a UTF-8 string but treating it as Latin-1 and re-encoding it as UTF-8. I'd guess that Nokogiri is reading the page and thinking that it is Latin-1 or being told by your user agent that it is getting Latin-1 text. Perhaps you have a bad default encoding somewhere, or the HTTP headers are lying about the encoding, or the page itself is lying about its encoding.
You need to get everything into UTF-8 at the edges of your scraper. Figure out who is lying about the encoding and sort it out right there.
Don't feel bad, scraping and encoding is a nightmare of confusion, stupidity, guesswork, and hard liquor. Servers lie, pages lie, browsers lie, no one is happy.

Strange characters returned after screen scraping using Ruby/Nokogiri?

I'm using Ruby and Nokogiri to scrape data off a client's legacy system.
The text I'm getting contains a trademark symbol. But when I display it on the console or save it to the database, the TM gets converted to a different character.
Diet™ BECOMES Dietâ¢
I'm pretty sure it's just an encoding problem and I'm pretty sure Ruby has an easy way to deal with it, but after several minutes of googling and trying a few obvious options, I'm not any closer.
Thanks in advance!
You have an encoding mismatch, but you haven't told us enough to help you.
Things to check:
What encoding does the server say their page is? It'll be in the HTTPD headers returned.
Is the document REALLY encoded as the server says, or are there characters that are not in that codeset?
Typically, you'll get documents as UTF-8, ISO-8859-1 or Win-1252, so try using those values to give Nokogiri a hint. The documentation for Nokogiri::HTML.parse says:
parse(thing, url = nil, encoding = nil, options = XML::ParseOptions::DEFAULT_HTML, &block)
Where:
encoding is the encoding that should be used when processing the document.
One way to figure out what the server is sending back is:
require 'open-uri'
open('http://www.example.net') { |io| io.charset }
# => "iso-8859-1"
Warning: What the server sends back is not necessarily what the content really is, so it's only a preliminary hint. The document returned could be anything, and at that point you're on your own to figure out what it is.
Typically we use Nokogiri::HTML('some html to parse'), but you can use:
Nokogiri::HTML('some html to parse', nil, 'UTF-8')
Look at Ruby's Encoding to figure out what the available codesets are:
Encoding.constants

Encoding error in content get from open-uri in ruby on rails

In some cases when I use open to get a web page in Ruby the content of the page has an encoding error. Example:
open("http://www.google.com.br").read
Chars like ç and ã are replaced by ?
How can I get the right chars?
this seems to work:
require 'iconv'
i = Iconv.new('UTF-8','LATIN1')
i.iconv(open('http://google.com.br').read)
Running Ruby 1.9.2 here. Your code yields HTML which contains words like this:
Configura\xE7\xF5es
So on my work machine at least (Vista, using Windows CMD console), it returns HTML escaped characters.
Also, as far as I know, Ruby 1.9.2 is "almost" fully Unicode compliant, so I am guessing you shouldn't have UTF-8 issues unless your console cannot handle printing UTF-8 characters.
Hope that helps.

Detect encoding

I'm getting some string data from the web, and I suspect that it's not always what it says it is. I don't know where the problem is, and I just don't care any more. From day one on this project I've been fighting Ruby string encoding. I really want some way to say: "Here's a string. What is it?", and then use that data to get it to UTF-8 so that it doesn't explode gsub() 2,000 lines down in the depths of my app. I've checked out rchardet, but even though it supposedly works for 1.9 now, it just blows up given any input with multiple bytes... which is not helpful.
You can't really detect the encoding. You can only assume it.
For the most Western languages applications, the following construct
will work. The traditional encoding usually is "ISO-8859-1". The new and preferred encoding is UTF-8. Why not simply try to encode it with UTF-8 and fallback with the old encoding
def detect_encoding( str )
begin
str.encode("UTF-8")
"UTF-8"
rescue
"ISO-8859-1"
end
end
It is impossible to tell from a string what encoding it is in. You always need some additional metadata that tells you what the string's encoding is.
If you get the string from the web, that metadata is in the HTTP headers. If the HTTP headers are wrong, there is absolutely nothing that you or Ruby or anyone else can do. You need to file a bug with the webmaster of the site where you got the string from and wait till he fixes it. If you have a Service Level Agreement with the website, file a bug, wait a week, then sue them.
Old question, but chardet works on 1.9: http://rubygems.org/gems/chardet
why not try use https://github.com/brianmario/charlock_holmes to get the exact encoding. Then also use it to convert to UTF8
require 'charlock_holmes'
class EncodeParser
def initialize(text)
#text = text
end
def detected_encoding
CharlockHolmes::EncodingDetector.detect(#text)[:encoding]
end
def convert_to_utf8
CharlockHolmes::Converter.convert(#text, detected_encoding, "UTF-8")
end
end
then just use EncodeParser.new(text).detected_encoding or EncodeParser.new(text). convert_to_utf8
We had some fine experience with ensure_encoding. It actually does the job for us to convert resource files having unknown encoding to UTF-8.
The README will give you some hints which options would be a good fit for your situation.
I have never tried chardet since ensure_encoding did the job just fine for us.
I covered here how we use ensure_encoding.
Try setting these in your environment.
export LC_ALL=en_US.UTF-8
export LC_CTYPE=en_US.UTF-8
Try ruby -EBINARY or ruby -EASCII-8BIT to command line
Try adding -Ku or -Kn to your ruby command line.
Could you paste the error message ?
Also try this: http://github.com/candlerb/string19/blob/master/string19.rb
Might try reading this: http://yehudakatz.com/2010/05/05/ruby-1-9-encodings-a-primer-and-the-solution-for-rails/
I know it's an old question, but in modern versions of Ruby it's as simple as str.encoding. You get a return value something like this: #Encoding:UTF-8

Resources