Nokogiri::XML parse value based on another XML attribute's value - ruby-on-rails

Question

Using Nokogiri::XML how can I retrieve a attribute's value based on another attribute?
XML file:
<RateReplyDetails>
<ServiceType>INT</ServiceType>
<Price>1.0</Price>
</RateReplyDetails>
<RateReplyDetails>
<ServiceType>LOCAL</ServiceType>
<Price>2.0</Price>
</RateReplyDetails>
And I would like to retrieve the Price of the LOCAL ServiceType which is 2.0
I could take the value without any condition with this:
rated_shipment.at('RateReplyDetails/Price').text
And probably I could do something like:
if rated_shipment.at('RateReplyDetails/ServiceType').text == "LOCAL"
rated_shipment.at('RateReplyDetails/Price').text
But is there any elegant and clean way of doing so?

Answer 1

I'd do something like:
require 'nokogiri'
doc = Nokogiri::XML(<<EOT)
<xml>
<RateReplyDetails>
<ServiceType>INT</ServiceType>
<Price>1.0</Price>
</RateReplyDetails>
<RateReplyDetails>
<ServiceType>LOCAL</ServiceType>
<Price>2.0</Price>
</RateReplyDetails>
</xml>
EOT
service_type = doc.at('//RateReplyDetails/*[text() = "LOCAL"]')
service_type.name # => "ServiceType"
'//RateReplyDetails/*[text() = "LOCAL"]' is an XPath selector that looks for the < RateReplyDetails> node that contains a text node equal to "LOCAL" and returns the node containing the text, which is the <ServiceType> node.
service_type.next_element.text # => "2.0"
Once we've found that it's easy to look at the next element and get its text.

Answer 2

try, content is the xml content string.
doc = Nokogiri::HTML(content)
doc.at('servicetype:contains("INT")').next_element.content
[16] pry(main)>
doc.at('servicetype:contains("INT")').next_element.content
=> "1.0"
[17] pry(main)>
doc.at('servicetype:contains("LOCAL")').next_element.content
=> "2.0"
I have test it, it's working.

Answer 3

Fully in XPath:
rated_shipment.at('//RateReplyDetails[ServiceType="LOCAL"]/Price/text()').to_s
# => "2.0"
EDIT:
it didnt work for me
Full code as proof it does work:
#!/usr/bin/env ruby
require 'nokogiri'
rated_shipment = Nokogiri::XML(DATA)
puts rated_shipment.at('//RateReplyDetails[ServiceType="LOCAL"]/Price/text()').to_s
__END__
<xml>
<RateReplyDetails>
<ServiceType>INT</ServiceType>
<Price>1.0</Price>
</RateReplyDetails>
<RateReplyDetails>
<ServiceType>LOCAL</ServiceType>
<Price>2.0</Price>
</RateReplyDetails>
</xml>
(outputs 2.0.) If it does not work, then it is because your file contents do not match your OP.