CODEWITHSUNDEEP
rubyxmlxpathnokogiri
David Smith
David Smith

Reputation:

Get element text from XML doc

I'm trying to extract some information from XML from Weather Underground.

I can open the resource and pull out the desired elements, but I really want to return the element text as a variable, without the containing XML element tags, so I can manipulate it and display it on a web page.

Perhaps there is a way to do this using regexp to strip off the tags, but I suspect/hope I can do this in a more elegant fashion directly in Nokogiri.

Currently I am using irb to work out the syntax:

irb>require 'rubygems'
irb>require 'nokogiri'
irb>require 'open-uri'
irb>doc = Nokogiri::XML(open('http://api.wunderground.com/auto/wui/geo/WXCurrentObXML/index.xml?query=KBHB'))
=> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd">
=> <?xml version="1.0"?>
# [...]
<!-- 0.036:0 -->

irb>doc.xpath('/current_observation/weather')
=> <weather>Clear</weather>irb(main):019:0> 
irb>doc.xpath('/current_observation/wind_dir')
=> <wind_dir>North</wind_dir>
irb>doc.xpath('/current_observation/wind_mph')
=> <wind_mph>10</wind_mph>
irb>doc.xpath('/current_observation/pressure_string')
=> <pressure_string>31.10 in (1053 mb)</pressure_string>

I need help with the specific syntax while using constructs such as:

doc.xpath.element('/current_observation/weather')
doc.xpath.text('/current_observation/weather')
doc.xpath.node('/current_observation/weather')
doc.xpath.element.text('/current_observation/weather')

All return errors.

Upvotes: 0

Views: 1971

Answers (3)

the Tin Man
the Tin Man

Reputation: 160551

One of the nice things about Nokogiri is its flexibility when writing accessors. You're not limited to XPath only, instead you can use CSS accessors:

require 'rubygems'
require 'nokogiri'
require 'open-uri'

doc = Nokogiri::XML(open('http://api.wunderground.com/auto/wui/geo/WXCurrentObXML/index.xml?query=KBHB'))

weather_report = %w[weather wind_dir wind_mph pressure_string].inject({}) { |h, n|
  h[n.to_sym] = doc.at('current_observation ' << n).text
  h 
} 
weather_report # => {:weather=>"Overcast", :wind_dir=>"South", :wind_mph=>"6", :pressure_string=>"29.67 in (1005 mb)"}

Upvotes: 0

Filip Dupanović
Filip Dupanović

Reputation: 33640

As per XPath, you can return the text node of an element with text().

In your example it should be doc.xpath('/current_observation/weather/text()') to get the content of weather's text node.

Upvotes: 1

ire_and_curses
ire_and_curses

Reputation: 70142

Something like this works for me:

irb(main):019:0> doc.xpath('//current_observation/weather').first.content
=> "Clear"

Upvotes: 0

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