The question was re-written.
I'm working on a simple web framework, and encountered a strange behavior from either Rack or the Thin server I'm using.
I tried to simplify the config.ru file as much as I could to gain the following code which reproduces the strange problem:
app = Proc.new do |env|
content = "<p>عربي</p>"
headers = {'Content-Type' => 'html/text; charset=utf-8', 'Content-Length' => content.length.to_s}
[200, headers, [content]]
end
run app
The code above is a normal Rack process, with the content a HTML paragraph which contains an Arabic word of four letters. Now, running Thin server: thin start, I was waiting for the source of the web page to be:
<p>عربي</p>
While it turned to be:
<p>عربي
Only, without the closing tag. The server works correctly if I inserted an English word instead of the Arabic one, so I concluded that the problem is related to the encoding or multibyte characters of Arabic.
I'm using Ruby 1.9.2. The encoding of the file is UTF-8. And Ruby works well if I just try puts "<p>عربي</p>" in the console without the Rack or Thin server.
So, the problem is simply disappearing of a number of characters after the Arabic text when using Rack and Thin + the number of disappearing characters == the number of the Arabic characters in the text.
Any thoughts?
Does 'Content-Length' => content.bytesize.to_s improve things?
Well, you have to tell Ruby that the string has Arabic in it. Use the force_encoding method with whatever encoding supports those Arabic characters:
str.force_encoding("nameOfArabicEncoding")
Related
I'm trying to get a list of files from url like this:
require 'uri'
require 'open-uri'
url = 'http://www.wmprof.com/media/niti/download'
html = open(url).read
puts URI.extract(html).select{ |link| link[/(PL)/]}
This code returns ArgumentError: invalid byte sequence in UTF-8 in line with URI.extract (even though html.encoding returns utf-8)
I've found some solutions to encoding problems, but when I'm changing the code to
html.encode('UTF-8', invalid: :replace, undef: :replace, replace: '?')
URI.extract returns empty string, even when I'm not calling the select method on it. Any suggestions?
The character encoding of the website might be ISO-8859-1 or a related one. We can't tell for sure since there are only two occurrences of the same non-US-ASCII-character and it doesn't really matter anyway.
html.each_char.reject(&:ascii_only?) # => ["\xDC", "\xDC"]
Finding the actual encoding is done by guessing. The age of HTML 3.2 or the used language/s might be a clue. And in this case especially the content of the PDF file is helpful (it contains SPRÜH-EX and the file has the name TI_DE_SPR%dcH_EX.pdf). Then we only need to find the encoding for which "\xDC" and "Ü" are equal. Either by knowing it or writing some Ruby:
Encoding.list.select { |e| "Ü" == "\xDC".encode!(Encoding::UTF_8, e) rescue next }.map(&:name)
Of course, letting a program do the guessing is an option too. There is the libguess library. The web browser can do it too. However you you need to download the file though unless the server might tell the browser it's UTF-8 even if it isn't (like in this case). Any decent text editor will also try to detect the file encoding: e.g. ST3 thinks it's Windows 1252 which is a superset of ISO-8859-1 (like UTF-8 is of US-ASCII).
Possible solutions are manually setting the string encoding to ISO-8859-1:
html.force_encoding(Encoding::ISO_8859_1)
Or (preferably) transcoding the string from ISO-8859-1 to UTF-8:
html.encode!(Encoding::UTF_8, Encoding::ISO_8859_1)
To answer the other question: URI.extract isn't the method you're looking for. Apparently it's obsolete and more importantly, it doesn't extract relative URI.
A simple alternative is using a regular expression with String#scan. It works with this site but it might not with other ones. You have to use a HTML parser for the best reliability (there might be also a gem). Here's an example that should do what you want:
html.scan(/href="(.*?PL.*?)"/).flatten # => ["SI_PL_ACTIV_bicompact.pdf", ...]
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.
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
We encounter the said error on some of our newer virtual machines, while other machines remain unaffected and wonder why and furthermore how to get rid of them.
the two main differences are as follows
vm_old:
debian squeeze
ruby1.9.2p0
vm_new:
debian wheezy
ruby1.9.2p320 (over rvm)
There naturally are more changes within the VMs, but i don't know which would affect this behavior.
We have a response containing umlauts within some of our controllers (ie. '{"message": "ü"}') and we have set # encoding: utf-8
Within the spec we test the response against a fixed string with this umlaut
it 'should test something' do
get :some_controller, format: :json
response.status.should == 200
json = ActiveSupport::JSON.decode(response.body)
json["message"].should == 'ü' # breaks on this line
# ... some more tests
end
The substitute for ü seems to be a random 4 digit string.
On occasion this string seems to be valid utf-8 and can be transfered.
We then have a failed spec instead of the error message in the title, since the random string is not the same as ü.
The spec file itself also has the # encoding: utf-8 on the first line.
We tried playing with the locale or with force_encoding('utf-8')
The question now becomes:
Has someone else encountered a problem like this?
and
How to solve it?
Edit: turns out it is not always starting with P\.
Edit 2:
Testing around showed it is a problem with the json decode.
The controller response is something like "{\"foo\": \"\u00fc\"}", decoding that results in random output where the sequence \u00fc used to be.
for simple reproduction:
bundle exec rails c
> ActiveSupport::JSON.decode(ActiveSupport::JSON.encode({:foo => "ü"})
rails version is 3.0.4
Edit 3:
Changing the JSON backend to Yaml seems to be a valid workaround.
I'm not certain if this will be of help to you, but I figured I'd toss it out there. For me, adding this code:
.encode('UTF-16le', :invalid => :replace, :replace => '').encode('UTF-8')
totally saved me. Essentially, it involves converting your UTF-8 encoding to UTF-16, and then encoding it back to UTF-8. More information is available here.
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.