루비에서 일부 값이 0 일 때 XmlSimple을 사용할 수 있습니까?

Question

nil이 XmlSimple을 막을 것이므로

>> require 'xmlsimple' 
=> true 

>> XmlSimple.xml_out([{'a' => 1}, {'a' => 3}]) 
=> "<opt>\n <anon a=\"1\" />\n <anon a=\"3\" />\n</opt>\n" 

그러나 다음과 같은 경우 오류가 발생합니다.

>> XmlSimple.xml_out([{'a' => 1}, {'a' => nil}]) 
ArgumentError: Use of uninitialized value! 
    from /Library/Ruby/Gems/1.8/gems/xml-simple-1.0.12/lib/xmlsimple.rb:798:in `value_to_xml' 
    from /Library/Ruby/Gems/1.8/gems/xml-simple-1.0.12/lib/xmlsimple.rb:794:in `each' 
    from /Library/Ruby/Gems/1.8/gems/xml-simple-1.0.12/lib/xmlsimple.rb:794:in `value_to_xml' 
    from /Library/Ruby/Gems/1.8/gems/xml-simple-1.0.12/lib/xmlsimple.rb:848:in `value_to_xml' 
    from /Library/Ruby/Gems/1.8/gems/xml-simple-1.0.12/lib/xmlsimple.rb:842:in `each' 
    from /Library/Ruby/Gems/1.8/gems/xml-simple-1.0.12/lib/xmlsimple.rb:842:in `value_to_xml' 
    from /Library/Ruby/Gems/1.8/gems/xml-simple-1.0.12/lib/xmlsimple.rb:807:in `value_to_xml' 
    from /Library/Ruby/Gems/1.8/gems/xml-simple-1.0.12/lib/xmlsimple.rb:794:in `each' 
    from /Library/Ruby/Gems/1.8/gems/xml-simple-1.0.12/lib/xmlsimple.rb:794:in `value_to_xml' 
    from /Library/Ruby/Gems/1.8/gems/xml-simple-1.0.12/lib/xmlsimple.rb:239:in `xml_out' 
    from /Library/Ruby/Gems/1.8/gems/xml-simple-1.0.12/lib/xmlsimple.rb:259:in `xml_out' 
    from (irb):4 

Answer 1

을 xml_out 당신은 nil 값을 피해야합니다. 다음 방법 중 하나를 사용하는 것이 좋습니다.

# To create an empty anon element: 
XmlSimple.xml_out([{'a' => 1}, {}]) 
=> "<opt>\n <anon a=\"1\" />\n <anon></anon>\n</opt>\n" 

# To create an anon element with a blank 'a' attribute: 
XmlSimple.xml_out([{'a' => 1}, {'a' => ''}]) 
=> "<opt>\n <anon a=\"1\" />\n <anon a=\"\" />\n</opt>\n" 

# To remove the attribute entirely (with value of 3), 
# but still create an empty anon tag: 
XmlSimple.xml_out([{'a' => 1}, {'-a' => 3}]) 
=> "<opt>\n <anon a=\"1\" />\n <anon />\n</opt>\n" 

# To remove the attribute entirely (with value of nil), 
# but still create an empty anon tag: 
XmlSimple.xml_out([{'a' => 1}, {'-a' => nil}]) 
=> "<opt>\n <anon a=\"1\" />\n <anon />\n</opt>\n" 

Answer 2

SuppressEmpty 옵션을 명령에 추가하기 만하면됩니다.
XmlSimple.xml_out ([{...}], 'SuppressEmpty'=> nil).

부터 - http://xml-simple.rubyforge.org/