Add Nokogiri as XmlMini backend

I'm getting failures if I actually enable nokogiri:

1) Error: test_array_with_multiple_entries_from_xml(HashToXmlTest): TypeError: can't convert String into Integer

./test/../lib/active_support/xml_mini/nokogiri.rb:38:in `[]'
./test/../lib/active_support/xml_mini/nokogiri.rb:38:in `to_hash'
./test/../lib/active_support/xml_mini/nokogiri.rb:52:in `call'
./test/../lib/active_support/xml_mini/nokogiri.rb:52:in `to_hash'
/Users/bart/.gem/ruby/1.8/gems/nokogiri-1.2.1/lib/nokogiri/xml/node_set.rb:139:in `each'
./test/../lib/active_support/xml_mini/nokogiri.rb:52:in `to_hash'
./test/../lib/active_support/xml_mini/nokogiri.rb:52:in `call'
./test/../lib/active_support/xml_mini/nokogiri.rb:52:in `to_hash'
/Users/bart/.gem/ruby/1.8/gems/nokogiri-1.2.1/lib/nokogiri/xml/node_set.rb:139:in `each'
./test/../lib/active_support/xml_mini/nokogiri.rb:52:in `to_hash'
./test/../lib/active_support/xml_mini/nokogiri.rb:55:in `call'
./test/../lib/active_support/xml_mini/nokogiri.rb:55:in `to_hash'
/Users/bart/.gem/ruby/1.8/gems/nokogiri-1.2.1/lib/nokogiri/xml/node_set.rb:139:in `each'
./test/../lib/active_support/xml_mini/nokogiri.rb:55:in `to_hash'
./test/../lib/active_support/xml_mini/nokogiri.rb:20:in `to_hash'
./test/../lib/active_support/xml_mini/nokogiri.rb:13:in `parse'
(__DELEGATION__):2:in `__send__'
(__DELEGATION__):2:in `parse'
./test/../lib/active_support/core_ext/hash/conversions.rb:153:in `from_xml'
./test/core_ext/hash_ext_test.rb:674:in `test_array_with_multiple_entries_from_xml'
/Library/Ruby/Gems/1.8/gems/mocha-0.9.5/lib/mocha/test_case_adapter.rb:69:in `__send__'
/Library/Ruby/Gems/1.8/gems/mocha-0.9.5/lib/mocha/test_case_adapter.rb:69:in `run'

2) Error: test_file_from_xml(HashToXmlTest): NoMethodError: undefined method original_filename' for {"content_type"=>"image/png", "name"=>"logo.png", "type"=>"file"}:Hash

./test/core_ext/hash_ext_test.rb:689:in `test_file_from_xml'
/Library/Ruby/Gems/1.8/gems/mocha-0.9.5/lib/mocha/test_case_adapter.rb:69:in `__send__'
/Library/Ruby/Gems/1.8/gems/mocha-0.9.5/lib/mocha/test_case_adapter.rb:69:in `run'

3) Error: test_file_from_xml_with_defaults(HashToXmlTest): NoMethodError: You have a nil object when you didn't expect it! The error occurred while evaluating nil.original_filename

./test/core_ext/hash_ext_test.rb:701:in `test_file_from_xml_with_defaults'
/Library/Ruby/Gems/1.8/gems/mocha-0.9.5/lib/mocha/test_case_adapter.rb:69:in `__send__'
/Library/Ruby/Gems/1.8/gems/mocha-0.9.5/lib/mocha/test_case_adapter.rb:69:in `run'

4) Error: test_multiple_records_from_xml(HashToXmlTest): TypeError: can't convert String into Integer

./test/../lib/active_support/xml_mini/nokogiri.rb:44:in `[]'
./test/../lib/active_support/xml_mini/nokogiri.rb:44:in `to_hash'
./test/../lib/active_support/xml_mini/nokogiri.rb:52:in `call'
./test/../lib/active_support/xml_mini/nokogiri.rb:52:in `to_hash'
/Users/bart/.gem/ruby/1.8/gems/nokogiri-1.2.1/lib/nokogiri/xml/node_set.rb:139:in `each'
./test/../lib/active_support/xml_mini/nokogiri.rb:52:in `to_hash'
./test/../lib/active_support/xml_mini/nokogiri.rb:55:in `call'
./test/../lib/active_support/xml_mini/nokogiri.rb:55:in `to_hash'
/Users/bart/.gem/ruby/1.8/gems/nokogiri-1.2.1/lib/nokogiri/xml/node_set.rb:139:in `each'
./test/../lib/active_support/xml_mini/nokogiri.rb:55:in `to_hash'
./test/../lib/active_support/xml_mini/nokogiri.rb:20:in `to_hash'
./test/../lib/active_support/xml_mini/nokogiri.rb:13:in `parse'
(__DELEGATION__):2:in `__send__'
(__DELEGATION__):2:in `parse'
./test/../lib/active_support/core_ext/hash/conversions.rb:153:in `from_xml'
./test/core_ext/hash_ext_test.rb:605:in `test_multiple_records_from_xml'
/Library/Ruby/Gems/1.8/gems/mocha-0.9.5/lib/mocha/test_case_adapter.rb:69:in `__send__'
/Library/Ruby/Gems/1.8/gems/mocha-0.9.5/lib/mocha/test_case_adapter.rb:69:in `run'

5) Failure: test_expansion_count_is_limited(QueryTest)

[./test/core_ext/hash_ext_test.rb:888:in `test_expansion_count_is_limited'
 /Library/Ruby/Gems/1.8/gems/mocha-0.9.5/lib/mocha/test_case_adapter.rb:69:in `__send__'
 /Library/Ruby/Gems/1.8/gems/mocha-0.9.5/lib/mocha/test_case_adapter.rb:69:in `run']:

exception expected but none was thrown.

6) Failure: test_default_is_rexml(REXMLEngineTest)

[./test/xml_mini/rexml_engine_test.rb:8:in `test_default_is_rexml'
 /Library/Ruby/Gems/1.8/gems/mocha-0.9.5/lib/mocha/test_case_adapter.rb:69:in `__send__'
 /Library/Ruby/Gems/1.8/gems/mocha-0.9.5/lib/mocha/test_case_adapter.rb:69:in `run']:

<ActiveSupport::XmlMini_REXML> expected but was <ActiveSupport::XmlMini_Nokogiri>.

1666 tests, 7289 assertions, 2 failures, 4 errors

If you run the entire rails test suite you'll get even more errors. Looks like the behaviour is different from Rexml. The LibXML implementation does not have this issue.

What version of nokogiri? How are you executing the tests? They all pass for me.

Also, do you have tests for the LibXML version? I'm glad to match behavior if it is spec'd.

Well, if you enable the nokogiri gem as default:

XmlMini.backend = 'Nokogiri'

and then run the rails test, you'll see a lot of issues where your nokogiri implementation has a different behaviour as the default REXML and LibXML implementation. This means that enabeling nokogiri will result in a rails which will behave wrong or dangerously ( 5 Failure: test_expansion_count_is_limited(QueryTest )

If you use XmlMini.backend = 'LibXML' you will only get 1 failure: test_default_is_rexml, which is obvious.

I can fix these. But I must make it clear that it does not behave dangerously. Expansion count is limited, but nokogiri corrects the document and doesn't raise an exception. :-)

Ok, but the behavior is still different :). I didn't look into the Nokogiri implementation. I do agree with you that this test needs to be automated somehow, for future xml implementations.

BTW: Nice work on the Nokogiri implementation :)

Anyone got a nice idea how to implement this in the active support rake file?

if gem 'libxml-ruby', '=0.9.7'
  XmlMini.backend = 'LibXML'
  run_entire_testsuite
end
if gem 'nokogiri'
  XmlMini.backend = 'Nokogiri'
  run_entire_testsuite
end

This is why my initial implementation automatically chose from the available back-ends :)

Oh yeah, could you put

   require 'nokogiri'

at the top of you mixin? That would make it function the same as the LibXML and REXML.

Hallo! I've attached a patch that fixes the nokogiri back end so that all rails tests pass.

Aaron,

You might want to check out this benchmark I just put together comparing all three XmlMini backends.

http://github.com/stepheneb/rail...

The benchmark runs Hash.from_xml on a 1.7MB XML file.

Summary: libxml-ruby was 25x faster than REXML while nokogiri was only 1.6 times faster.

Also: JRuby ran the REXML backend 3 times faster than MRI 1.8.6.

@Stephen

You're right. But LibXML seems to produce different results than REXML, where Nokogiri matches the REXML output.

I would say that because of that, this speed test is not exactly valid.

http://github.com/tenderlove/rai...

Hello

In which file do you set XmlMini.backend = 'Nokogiri' ?

I suppose I would do this in my environment.rb file.

Nope :(

/opt/local/lib/ruby/gems/1.8/gems/activesupport-2.3.2/lib/active_support/dependencies.rb:443:in `load_missing_constant': uninitialized constant XmlMini (NameError)
	from /opt/local/lib/ruby/gems/1.8/gems/activesupport-2.3.2/lib/active_support/dependencies.rb:80:in `const_missing'
	from /opt/local/lib/ruby/gems/1.8/gems/activesupport-2.3.2/lib/active_support/dependencies.rb:92:in `const_missing'
	from /Users/jerome/Sites/foo/config/environment.rb:45

Jérôme,

You should really be asking this question the mailing list. LH is not for general support. Also, use ActiveSupport::XmlMini.

Thanks.

Did you try ActiveSupport::XmlMini?

As apache says: it works !

Thanks.

Thank you Pratik. However it wasn't documented, not even on the announcement on the official rails blog.

Anyway it works, end of story. Thank you very much.