open xml file with nokogiri update node and save - ruby-on-rails

Question

I'm trying to figure out how to open an xml file, search by an id, replace a value in the node and then resave the document.
my xml
<?xml version="1.0"?>
<data>
<user id="1370018670618">
<email>1#1.com</email>
<sent>false</sent>
</user>
<user id="1370018701357">
<email>2#2.com</email>
<sent>false</sent>
</user>
<user id="1370018769724">
<email>3#3.com</email>
<sent>false</sent>
</user>
<user id="1370028546850">
<email>4#4.com</email>
<sent>false</sent>
</user>
<user id="1370028588345">
<email>5#5.com</email>
<sent>false</sent>
</user>
</data>
My code to open and find a node
xml_content = File.read("/home/mike/app/users.xml")
doc = Nokogiri::XML(xml_content)
node_update = doc.search("//user[#id='1370028588345'] //sent")
node_update.inner_html ##returns value of "sent"
the part in this where I'm stuck is actually updating the node. node_update.inner_html = "true" returns a method error on inner_html. then after that saving the updated file.

Answer 1

First of all, your node_update is actually a NodeSet, not the Node that you probably think it is. You need a Node if you want to call inner_html= on it:
node_update[0].inner_html = 'true'
Then writing out the updated XML is just a bit of standard file manipulating combined with a to_xml call:
File.open('whatever.xml', 'w') { |f| f.print(doc.to_xml) }
As an aside, your input isn't valid XML. You have a </details> but no <details>.