REXML parsing an XML in ruby - ruby

Question

Folks,
I am using REXML for a sample XML file:
<Accounts title="This is the test title">
<Account name="frenchcustomer">
<username name = "frencu"/>
<password pw = "hello34"/>
<accountdn dn = "https://frenchcu.com/"/>
<exporttest name="basic">
<exportname name = "basicexport"/>
<exportterm term = "oldschool"/>
</exporttest>
</Account>
<Account name="britishcustomer">
<username name = "britishcu"/>
<password pw = "mellow34"/>
<accountdn dn = "https://britishcu.com/"/>
<exporttest name="existingsearch">
<exportname name = "largexpo"/>
<exportterm term = "greatschool"/>
</exporttest>
</Account>
</Accounts>
I am reading the XML like this:
#data = (REXML::Document.new file).root
#dataarr = ##testdata.elements.to_a("//Account")
Now I want to get the username of the frenchcustomer, so I tried this:
#dataarr[#name=fenchcustomer].elements["username"].attributes["name"]
this fails, I do not want to use the array index, for example
#dataarr[1].elements["username"].attributes["name"]
will work, but I don't want to do that, is there something that i m missing here. I want to use the array and get the username of the french user using the Account name.
Thanks a lot.

Answer 1

I recommend you to use XPath.
For the first match, you can use first method, for an array, just use match.
The code above returns the username for the Account "frenchcustomer" :
REXML::XPath.first(yourREXMLDocument, "//Account[#name='frenchcustomer']/username/#name").value
If you really want to use the array created with ##testdata.elements.to_a("//Account"), you could use find method :
french_cust_elt = the_array.find { |elt| elt.attributes['name'].eql?('frenchcustomer') }
french_username = french_cust_elt.elements["username"].attributes["name"]

Answer 2

puts #data.elements["//Account[#name='frenchcustomer']"]
.elements["username"]
.attributes["name"]
If you want to iterate over multiple identical names:
#data.elements.each("//Account[#name='frenchcustomer']") do |fc|
puts fc.elements["username"].attributes["name"]
end

Answer 3

I don't know what your ##testdata are, I tried with the following testcode:
require "rexml/document"
#data = (REXML::Document.new DATA).root
#dataarr = #data.elements.to_a("//Account")
# Works
p #dataarr[1].elements["username"].attributes["name"]
#Works not
#~ p #dataarr[#name='fenchcustomer'].elements["username"].attributes["name"]
##dataarr is an array
#dataarr.each{|acc|
next unless acc.attributes['name'] =='frenchcustomer'
p acc.elements["username"].attributes["name"]
}
##dataarr is an array
puts "===Array#each"
#dataarr.each{|acc|
next unless acc.attributes['name'] =='frenchcustomer'
p acc.elements["username"].attributes["name"]
}
puts "===XPATH"
#data.elements.to_a("//Account[#name='frenchcustomer']").each{|acc|
p acc.elements["username"].attributes["name"]
}
__END__
<Accounts title="This is the test title">
<Account name="frenchcustomer">
<username name = "frencu"/>
<password pw = "hello34"/>
<accountdn dn = "https://frenchcu.com/"/>
<exporttest name="basic">
<exportname name = "basicexport"/>
<exportterm term = "oldschool"/>
</exporttest>
</Account>
<Account name="britishcustomer">
<username name = "britishcu"/>
<password pw = "mellow34"/>
<accountdn dn = "https://britishcu.com/"/>
<exporttest name="existingsearch">
<exportname name = "largexpo"/>
<exportterm term = "greatschool"/>
</exporttest>
</Account>
</Accounts>
I'm not very familiar with rexml, so I expect there is a better solution. But perhaps aomebody can take my code to build a better solution.