XML Nokogiri Request won't stop auto ordering hash keys? - ruby-on-rails

Question

I am using ruby 2.0.0 and the Nokogiri gem. I have the following code:
builder = Nokogiri::XML::Builder.new do |xml|
xml['s'].Envelope('xmlns:s' => "http://schemas.xmlsoap.org/soap/envelope/") {
xml['s'].Body {
xml.GetList('xmlns' => "http://tempuri.org/") {
xml.listRequest('i:type' => "b:NpsListRequest", 'xmlns:a' => "http://schemas.datacontract.org/2004/07/Services.List", 'xmlns:i' => "http://www.w3.org/2001/XMLSchema-instance", 'xmlns:b' => "http://schemas.datacontract.org/2004/07/Services.List.Strategies")
}
}
}
end
The above is incomplete. I need to pass in an ID to actually make the call, however this is what the above returns:
<?xml version="1.0" encoding="ISO-8859-1"?>
<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/">
<s:Body>
<GetList xmlns="http://tempuri.org/">
<listRequest xmlns:a="http://schemas.datacontract.org/2004/07/Services.List" xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns:b="http://schemas.datacontract.org/2004/07/Services.List.Strategies" i:type="b:NpsListRequest"/>
</GetList>
</s:Body>
</s:Envelope>
The issue is with the <listRequest xmlns:a code block. In the XML I am creating, I am passing in i:type as the first key, however the response is putting xmlns:a as the first key. Why is that happening?

Answer 1

You are using Nokogiri Builder to create XML attributes.
The XML specification declares that attribute order is not significant. See the XML Specification specifically Section 3.1 where it says:
the order of attribute specifications in a start-tag ... is not significant.
Therefore, the specific way it is handled by an XML library is undefined, but all will produce valid results.