Converting raw XML query to Savon 2 Format

Question 1

have you looked into the resulting XML message?

you should set the parameters

log => true,
log_level => :debug,
pretty_print_xml => true

and have a look.

Question 2

I recently dealt with this same problem. NWMLS uses a special root key called v_strXmlQuery that includes a nested XML string. This works just fine for me:

[1] pry(main)> require 'savon'
=> true
[2] pry(main)> client = Savon.client(
[2] pry(main)*   wsdl: "http://evernet.nwmls.com/evernetqueryservice/evernetquery.asmx?wsdl",
[2] pry(main)* convert_request_keys_to: :none); # this is important
=> #<Savon::Client:0x007fbf5a324288
  ...
[4] pry(main)> username = 'myusername'
[5] pry(main)> password = 'mypassword'
[7] pry(main)> message =  {v_strXmlQuery:"<?xml version=\"1.0\" encoding=\"UTF-8\"?><EverNetQuerySpecification xmlns=\"urn:www.nwmls.com/Schemas/General/EverNetQueryXML.xsd\"><Message><Head><UserId>#{username}</UserId><Password>#{password}</Password><SchemaName>#{schema_name}</SchemaName></Head><Body><Query><MLS>NWMLS</MLS><PropertyType>RESI</PropertyType><Status>A</Status><County>King</County><City>Seattle</City><BeginDate>2005-08-27T16:14:09</BeginDate><EndDate>2015-08-28T09:14:09</EndDate></Query><Filter></Filter></Body></Message></EverNetQuerySpecification>"}y><BeginDate>2005-08-27T16:14:09</BeginDate><EndDate>2015-08-28T09:14:09</EndDate></Query><Filter></Filter></Body></Message></EverNetQuerySpecification>"}
=> {:v_strXmlQuery=>
  "<?xml version=\"1.0\" encoding=\"UTF-8\"?><EverNetQuerySpecification xmlns=\"urn:www.nwmls.com/Schemas/General/EverNetQueryXML.xsd\"><Message><Head><UserId>myusername</UserId><Password>mypassword</Password><SchemaName>StandardXML1_3</SchemaName></Head><Body><Query><MLS>NWMLS</MLS><PropertyType>RESI</PropertyType><Status>A</Status><County>King</County><City>Seattle</City><BeginDate>2005-08-27T16:14:09</BeginDate><EndDate>2015-08-28T09:14:09</EndDate></Query><Filter></Filter></Body></Message></EverNetQuerySpecification>"}

[8] pry(main)> client.call(:retrieve_listing_data, message: message).body
...
=> {:retrieve_listing_data_response=>
  {:retrieve_listing_data_result=>
    "<Listings xmlns=\"http://www.nwmls.com/Schemas/Standard/StandardXML1_3.xsd\"><Residential>...<MR>Timeless, top of the line finish work in this studs-out craftsman remodel.  This remodel has everything desired in a home: open floor plan, rich hardwood flooring,...

I'd suggest using an XML builder like Savon's Gyoku gem to construct the sub hash and attach the xml header/footer, then inject it into the parent document query:

# takes a query hash and generates correctly-formatted SOAP-friendly XML
class QueryGenerator

  def self.call(hash)
    new.call(hash)
  end

  def call(hash)
    _xml = Gyoku.xml(hash, key_converter: :camelcase)
    repaired_xml = fix_weird_keys(_xml)
    wrapped_xml = xml_header + repaired_xml + xml_footer
    { v_strXmlQuery: wrapped_xml }
  end

  def xml_header
    "<?xml version=\"1.0\" encoding=\"UTF-8\"?><EverNetQuerySpecification xmlns=\"urn:www.nwmls.com/Schemas/General/EverNetQueryXML.xsd\"><Message>"
  end

  def xml_footer
    "</Message></EverNetQuerySpecification>"
  end

  # because its all Camelcase, except for that one that aint
  def fix_weird_keys(xml_str)
    xml_str.gsub('<Mls>','<MLS>').
            gsub('</Mls>','</MLS>')
  end
end

query_hash = {
  head: {
    user_id:     'myusername',
    password:    'mypassword',
    schema_name: 'StandardXML1_3'
  },
  body: {
    query: {
      mls: 'NWMLS',
      property_type: 'RESI',
      status: 'A',
      city: 'Seattle',
      begin_date: '2014-04-17T00:25:00',
      end_date: '2014-04-22T00:25:00'
    },
    filter: {}
  }
}
listing_data_query =  QueryGenerator.call(query_hash)
client.call(:retrieve_listing_data, message: listing_data_query )