How to set the mechanize page encoding? - ruby

I'm trying to get a page with an ISO-8859-1 encoding clicking on a link, so the code is similar to this:
page_result = page.link_with( :text => 'link_text' ).click
So far I get the result with a wrong encoding, so I see characters like:
'T�tulo:' instead of 'Título:'
I've tried several approaches, including:
Stating the encoding in the first request using the agent like:
#page_search = #agent.get(
:url => 'http://www.server.com',
:headers => { 'Accept-Charset' => 'ISO-8859-1' } )
Stating the encoding for the page itself
page_result.encoding = 'ISO-8859-1'
But I must be doing something wrong: a simple puts always show the wrong characters.
Do you know how to state the encoding?
Thanks in advance,
Added: Executable example:
require 'rubygems'
require 'mechanize'
WWW::Mechanize::Util::CODE_DIC[:SJIS] = "ISO-8859-1"
#agent = WWW::Mechanize.new
#page = #agent.get(
:url => 'http://www.mcu.es/webISBN/tituloSimpleFilter.do?cache=init&layout=busquedaisbn&language=es',
:headers => { 'Accept-Charset' => 'utf-8' } )
puts #page.body

Hey you can just do a:
agent.page.encoding = 'utf-8'
Hope it helps!

The previous answer is correct, but in my code it looks slightly different:
agent = Mechanize.new
page = agent.get('http://example.com')
page.encoding = 'windows-1251'
page.search('p').each do |para|
puts para.text
end

Sorry, it was my mistake: I come from a Java background and there strings are internally converted to utf-16. I forgot Ruby doesn't do it. Mechanize was recovering the page flawlessly, but I needed to convert the data via iconv.
Mental note: Ruby stores the strings without converting its encoding.

Yeah, Mechanize will try to detect the encoding itself (using the NKF core Ruby library) to guess the encoding) and sometimes fails.
Maybe this might help:
WWW::Mechanize::Util::CODE_DIC[:SJIS] = "ISO-8859-1"
I'm not too sure about the exact syntax, but I think the CODE_DICT Hash might be a good place to look :)
I had a similar problem a while back.

Related

SmarterCSV and file encoding issues in Ruby

I'm working with a file that appears to have UTF-16LE encoding. If I run
File.read(file, :encoding => 'utf-16le')
the first line of the file is:
"<U+FEFF>=\"25/09/2013\"\t18:39:17\t=\"Unknown\"\t=\"+15168608203\"\t\"Message.\"\r\n
If I read the file using something like
csv_text = File.read(file, :encoding => 'utf-16le')
I get an error stating
ASCII incompatible encoding needs binmode (ArgumentError)
If I switch the encoding in the above to
csv_text = File.read(file, :encoding => 'utf-8')
I make it to the SmarterCSV section of the code, but get an error that states
`=~': invalid byte sequence in UTF-8 (ArgumentError)
The full code is below. If I run this in the Rails console, it works just fine, but if I run it using ruby test.rb, it gives me the first error:
require 'smarter_csv'
headers = ["date_of_message", "timestamp_of_message", "sender", "phone_number", "message"]
path = '/path/'
Dir.glob("#{path}*.CSV").each do |file|
csv_text = File.read(file, :encoding => 'utf-16le')
File.open('/tmp/tmp_file', 'w') { |tmp_file| tmp_file.write(csv_text) }
puts 'made it here'
SmarterCSV.process('/tmp/tmp_file', {
:col_sep => "\t",
:force_simple_split => true,
:headers_in_file => false,
:user_provided_headers => headers
}).each do |row|
converted_row = {}
converted_row[:date_of_message] = row[:date_of_message][2..-2].to_date
converted_row[:timestamp] = row[:timestamp]
converted_row[:sender] = row[:sender][2..-2]
converted_row[:phone_number] = row[:phone_number][2..-2]
converted_row[:message] = row[:message][1..-2]
converted_row[:room] = file.gsub(path, '')
end
end
Update - 05/13/15
Ultimately, I decided to encode the file string as UTF-8 rather than diving deeper into the SmarterCSV code. The first problem in the SmarterCSV code is that it does not allow a user to specify binary mode when reading in a file, but after adjusting the source to handle that, a myriad of other encoding-related issues popped-up, many of which related to the handling of various parameters on files that were not UTF-8 encoded. It may have been the easy way out, but encoding everything as UTF-8 before feeding it into SmarterCSV solved my issue.
Add binmode to the File.read call.
File.read(file, :encoding => 'utf-16le', mode: "rb")
"b" Binary file mode
Suppresses EOL <-> CRLF conversion on Windows. And
sets external encoding to ASCII-8BIT unless explicitly
specified.
ref: http://ruby-doc.org/core-2.0.0/IO.html#method-c-read
Now pass the correct encoding to SmarterCSV
SmarterCSV.process('/tmp/tmp_file', {
:file_encoding => "utf-16le", ...
Update
It was found that smartercsv does not support binary mode. After the OP attempted to modify the code with no success it was decided the simple solution was to convert the input to UTF-8 which smartercsv supports.
Unfortunately, you're using a 'flat-file' style of storage and character encoding is going to be an issue on both ends (reading or writing).
I would suggest using something along the lines of str = str.force_encoding("UTF-8") and see if you can get that to work.

is it possible to convert Mechanize::File into Mechanize::Page

I'm having a trouble with Mechanize gem, how to convert Mechanize::File into Mechanize::Page,
here's my piece of code:
**link** = page.link_with(:href => %r{/en/users}).click
when users link clicked it goes to the page with the list of users, now i want to click the first user, but i can't achieve this, because link return Mechanize::File object
Any help, suggestions 'd be great, thanks
Mechanize uses Content-Type to determine how the resource should be handled. Occasionally websites will not set the mime-types for their resources. Mechanize::File is the default for unset Content-Type.
If you are only dealing with 'text/html' you can following Jimm Stout's suggestion of using post_connect_hooks
agent = Mechanize.new do |a|
a.post_connect_hooks << ->(_,_,response,_) do
if response.content_type.empty?
response.content_type = 'text/html'
end
end
end
Just parse the body with nokogiri:
link = page.link_with(:href => %r{/en/users}).click
doc = Nokogiri::HTML link.body
agent.get doc.at('a')[:href]

Nokogiri and Mechanize problem

I am doing one the examples at the mechanize doc site and I want to parse the results using
nokogiri.
My problem is that when the following line gets executed:
doc = Nokogiri::HTML(search_results, 'UTF-8' )
the following error occurs:
C:/Ruby192/lib/ruby/gems/1.9.1/gems/nokogiri-1.4.4.1-x86-mingw32/lib/nokogiri/html/document.rb:71:in `parse': undefined method `name' for "UTF-8":String (NoMethodError)
from C:/Ruby192/lib/ruby/gems/1.9.1/gems/nokogiri-1.4.4.1-x86-mingw32/lib/nokogiri/html.rb:13:in `HTML'
from mechanize_test.rb:16:in `<main>'
I have installed ruby 1.9 on a windows vista machine
The results returned by mechanize are non-latin (utf8)
The code sample follows.
# encoding: UTF-8
require 'rubygems'
require 'mechanize'
require 'nokogiri'
agent = Mechanize.new
agent.user_agent_alias = 'Mac Safari'
page = agent.get("http://www.google.com/")
search_form = page.form_with(:name => "f")
search_form.field_with(:name => "q").value = "invitations"
search_results = agent.submit(search_form)
puts search_results.body
doc = Nokogiri::HTML(search_results, 'UTF-8')
#Douglas Drouillard
Thanx for looking into this. I found out I made a mistake. The call to nokogiri should have been:
doc = Nokogiri::HTML(search_results.body, 'UTF-8')
Note that search_results is different that search_results.body.
Search_results contains info coming right out of mechanize instantiation
while search_resuls.body contains html utf8 info that nokogiri can parse with no problem.
This appears to be issue with what Nokogiri expects as parameters to the parse method that is being called. The first issue I see, is that you are passing in the encoding option in the wrong parameter slot,
A parsing example from Nokogiri project page that specifies encoding
Nokogiri.XML('<foo><bar /><foo>', nil, 'EUC-JP')
Notice the encoding is the third parameter, not the second. But that still does not fully explain the behavior you are seeing, as the encoding should simply be ignored.
Per the Nokogiri documentation a call to Nokogiri::HTML() is a convenience method for the parse method.
Code for Nokogiri::HTML::parse
def parse thing, url = nil, encoding = nil, options = XML::ParseOptions::DEFAULT_HTML, &block
document.parse(thing, url, encoding, options, &block)
end
The source for the Nokogiri::HTML::Document parse method is a bit long, but here is the relevant part though:
string_or_io.respond_to?(:encoding)
unless string_or_io.encoding.name == "ASCII-8BIT"
encoding ||= string_or_io.encoding.name
end
end
Notice string_or_io.encoding.name, this matches the error your saw, undefined method 'name' for "UTF-8":String (NoMethodError).
Does your search_results object has an attribute with a key value pair of {:encoding => 'UTF-8'}? It appears Nokogiri is looking for the encoding to store an object that then has a name attribute of 'UTF-8'.

ruby 1.9: invalid byte sequence in UTF-8

I'm writing a crawler in Ruby (1.9) that consumes lots of HTML from a lot of random sites.
When trying to extract links, I decided to just use .scan(/href="(.*?)"/i) instead of nokogiri/hpricot (major speedup). The problem is that I now receive a lot of "invalid byte sequence in UTF-8" errors.
From what I understood, the net/http library doesn't have any encoding specific options and the stuff that comes in is basically not properly tagged.
What would be the best way to actually work with that incoming data? I tried .encode with the replace and invalid options set, but no success so far...
In Ruby 1.9.3 it is possible to use String.encode to "ignore" the invalid UTF-8 sequences. Here is a snippet that will work both in 1.8 (iconv) and 1.9 (String#encode) :
require 'iconv' unless String.method_defined?(:encode)
if String.method_defined?(:encode)
file_contents.encode!('UTF-8', 'UTF-8', :invalid => :replace)
else
ic = Iconv.new('UTF-8', 'UTF-8//IGNORE')
file_contents = ic.iconv(file_contents)
end
or if you have really troublesome input you can do a double conversion from UTF-8 to UTF-16 and back to UTF-8:
require 'iconv' unless String.method_defined?(:encode)
if String.method_defined?(:encode)
file_contents.encode!('UTF-16', 'UTF-8', :invalid => :replace, :replace => '')
file_contents.encode!('UTF-8', 'UTF-16')
else
ic = Iconv.new('UTF-8', 'UTF-8//IGNORE')
file_contents = ic.iconv(file_contents)
end
The accepted answer nor the other answer work for me. I found this post which suggested
string.encode!('UTF-8', 'binary', invalid: :replace, undef: :replace, replace: '')
This fixed the problem for me.
My current solution is to run:
my_string.unpack("C*").pack("U*")
This will at least get rid of the exceptions which was my main problem
Try this:
def to_utf8(str)
str = str.force_encoding('UTF-8')
return str if str.valid_encoding?
str.encode("UTF-8", 'binary', invalid: :replace, undef: :replace, replace: '')
end
I recommend you to use a HTML parser. Just find the fastest one.
Parsing HTML is not as easy as it may seem.
Browsers parse invalid UTF-8 sequences, in UTF-8 HTML documents, just putting the "�" symbol. So once the invalid UTF-8 sequence in the HTML gets parsed the resulting text is a valid string.
Even inside attribute values you have to decode HTML entities like amp
Here is a great question that sums up why you can not reliably parse HTML with a regular expression:
RegEx match open tags except XHTML self-contained tags
attachment = file.read
begin
# Try it as UTF-8 directly
cleaned = attachment.dup.force_encoding('UTF-8')
unless cleaned.valid_encoding?
# Some of it might be old Windows code page
cleaned = attachment.encode( 'UTF-8', 'Windows-1252' )
end
attachment = cleaned
rescue EncodingError
# Force it to UTF-8, throwing out invalid bits
attachment = attachment.force_encoding("ISO-8859-1").encode("utf-8", replace: nil)
end
This seems to work:
def sanitize_utf8(string)
return nil if string.nil?
return string if string.valid_encoding?
string.chars.select { |c| c.valid_encoding? }.join
end
I've encountered string, which had mixings of English, Russian and some other alphabets, which caused exception. I need only Russian and English, and this currently works for me:
ec1 = Encoding::Converter.new "UTF-8","Windows-1251",:invalid=>:replace,:undef=>:replace,:replace=>""
ec2 = Encoding::Converter.new "Windows-1251","UTF-8",:invalid=>:replace,:undef=>:replace,:replace=>""
t = ec2.convert ec1.convert t
While Nakilon's solution works, at least as far as getting past the error, in my case, I had this weird f-ed up character originating from Microsoft Excel converted to CSV that was registering in ruby as a (get this) cyrillic K which in ruby was a bolded K. To fix this I used 'iso-8859-1' viz. CSV.parse(f, :encoding => "iso-8859-1"), which turned my freaky deaky cyrillic K's into a much more manageable /\xCA/, which I could then remove with string.gsub!(/\xCA/, '')
Before you use scan, make sure that the requested page's Content-Type header is text/html, since there can be links to things like images which are not encoded in UTF-8. The page could also be non-html if you picked up a href in something like a <link> element. How to check this varies on what HTTP library you are using. Then, make sure the result is only ascii with String#ascii_only? (not UTF-8 because HTML is only supposed to be using ascii, entities can be used otherwise). If both of those tests pass, it is safe to use scan.
There is also the scrub method to filter invalid bytes.
string.scrub('')
If you don't "care" about the data you can just do something like:
search_params = params[:search].valid_encoding? ? params[:search].gsub(/\W+/, '') : "nothing"
I just used valid_encoding? to get passed it. Mine is a search field, and so i was finding the same weirdness over and over so I used something like: just to have the system not break. Since i don't control the user experience to autovalidate prior to sending this info (like auto feedback to say "dummy up!") I can just take it in, strip it out and return blank results.

Iconv::IllegalSequence when using www::mechanize

I'm trying to do a little bit of webscraping, but the WWW:Mechanize gem doesn't seem to like the encoding and crashes.
The post request results in a 302 redirect (which mechanize follows, so far so good) and the resulting page seems to crash it.
I googled quite a bit, but nothing came up so far how to solve this. Any of you got an idea?
Code:
require 'rubygems'
require 'mechanize'
agent = WWW::Mechanize.new
agent.user_agent_alias = 'Mac Safari'
answer = agent.post('https://www.budget.de/de/reservierung/privatkunden/step1/schnellbuchung',
{"Country" => "Deutschland",
"Abholstation" => "Aalen",
"Abgabestation" => "Aalen",
"Abholdatum" => "26.02.2009",
"Abholzeit_stunde" => "13",
"Abholzeit_minute" => "30",
"Abgabedatum" => "28.02.2009",
"Abgabezeit_stunde" => "13",
"Abgabezeit_minute" => "30",
"CountryID" => "DE",
"AbholstationID"=>"AA1",
"AbgabestationID"=>"AA1"
}
)
puts answer.body
Error:
D:/Ruby/lib/ruby/gems/1.8/gems/mechanize-0.9.1/lib/www/mechanize/util.rb:29:in `iconv': "\204nderungen vorbe"... (Iconv::IllegalSequence)
from D:/Ruby/lib/ruby/gems/1.8/gems/mechanize-0.9.1/lib/www/mechanize/util.rb:29:in `to_native_charset'
from D:/Ruby/lib/ruby/gems/1.8/gems/mechanize-0.9.1/lib/www/mechanize/chain/response_header_handler.rb:29:in `handle'
from D:/Ruby/lib/ruby/gems/1.8/gems/mechanize-0.9.1/lib/www/mechanize/chain.rb:30:in `pass'
from D:/Ruby/lib/ruby/gems/1.8/gems/mechanize-0.9.1/lib/www/mechanize/chain/handler.rb:6:in `handle'
from D:/Ruby/lib/ruby/gems/1.8/gems/mechanize-0.9.1/lib/www/mechanize/chain/response_body_parser.rb:35:in `handle'
from D:/Ruby/lib/ruby/gems/1.8/gems/mechanize-0.9.1/lib/www/mechanize/chain.rb:30:in `pass'
from D:/Ruby/lib/ruby/gems/1.8/gems/mechanize-0.9.1/lib/www/mechanize/chain/handler.rb:6:in `handle'
from D:/Ruby/lib/ruby/gems/1.8/gems/mechanize-0.9.1/lib/www/mechanize/chain/pre_connect_hook.rb:14:in `handle'
from D:/Ruby/lib/ruby/gems/1.8/gems/mechanize-0.9.1/lib/www/mechanize/chain.rb:25:in `handle'
from D:/Ruby/lib/ruby/gems/1.8/gems/mechanize-0.9.1/lib/www/mechanize.rb:494:in `fetch_page'
from D:/Ruby/lib/ruby/gems/1.8/gems/mechanize-0.9.1/lib/www/mechanize.rb:545:in `fetch_page'
from D:/Ruby/lib/ruby/gems/1.8/gems/mechanize-0.9.1/lib/www/mechanize.rb:403:in `post_form'
from D:/Ruby/lib/ruby/gems/1.8/gems/mechanize-0.9.1/lib/www/mechanize.rb:322:in `post'
from test.rb:7
That page is most certainly UTF-8, however Mechanize uses NKF (a core Ruby library) to guess the encoding and for some reason it comes up as Shift JIS. The quickest way to work around the problem is to override the encoding mapping for Mechanize, so that when it attempts to convert the body to UTF-8 using Iconv it passes in the source encoding as UTF-8 as well. You can do it like this:
WWW::Mechanize::Util::CODE_DIC[:SJIS] = "UTF-8"
Place that just after the line where you require the Mechanize library. You may want to set the value back immediately after, or even better, find the root cause of the problem and submit a patch if necessary.
Note: The way I solved this was by debugging the Mechanize library by using the backtrace. The to_native_charset method calls detect_charset which is where the problem was.
In my case a Mechanize::File was returned by the get method which doesn't use encoding at all.
I was able to fix it by manually converting with Iconv, but this only works if you know the encoding already.
result = #agent.get uri
# Mechanize::File instead of Mechanize::Page is returned
# so we have to convert manually
result = Iconv.conv("utf-8", "iso-8859-1", result.body)

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