如何使用Nokogiri解析返回的XML

Question

I'm attempting to parse this XML with nokogirl but I'm having trouble. Any ideas where I'm going wrong? I'd like to get each Dealer and get the values for each of them.

doc = Nokogiri::Slop(response.body)
puts doc.content #works, shows the response below
puts doc.DTX_LEAD_ID.content #errors, no method found.
puts doc.NEWCAR_PINGGX_RESPONSE.content #errors, no method found

returned XML:

<?xml version="1.0" encoding="utf-8"?>
<string xmlns="www.example.com/">
<?xml version="1.0" encoding="utf-8"?>
<NEWCAR_PINGGX_RESPONSE xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="www.example.com/SellerMessages">
    <DTX_LEAD_ID>1779853194</DTX_LEAD_ID>
    <SUCCESS>true</SUCCESS>
    <CACHED_RESPONSE>false</CACHED_RESPONSE>
    <PRICE>20</PRICE>
    <DealerList>
        <Dealer>
            <BUYER_ID>0000-2127</BUYER_ID>
            <Reservation_ID>1779853194|0000-2067|520a8037-57c8-497e-be4b-f4ea8dfa6c6f|14187-20</Reservation_ID>
            <Price>20</Price>
            <Name>Randy's Rides</Name>
            <State>MI</State>
            <City>Southfield</City>
            <Street>2001 Town Center</Street>
            <Postalcode>48076</Postalcode>
            <Distance>2.56002068066733</Distance>
            <DealerGroup id="2067" max_post="5" />
            <Contact><Name>John Campbell</Name>
            <Phone>2483521314</Phone>
            </Contact>
        </Dealer>
    </DealerList>
</NEWCAR_PINGGX_RESPONSE></string>

Previously I've had a response like this:

    <?xml version="1.0" encoding="utf-8"?>
    <results>
      <status>accepted</status>
      <id>1724128693</id>
      <purchaseprice>8.0000</purchaseprice>
      <error>false</error>
      <messages>
        <message>coverage available</message>
      </messages>
    </results>

Which parses really easily with nokogiri:

doc.results.messages.message.content #coverage available

I want to do something like:

doc.NEWCAR_PINGGX_RESPONSE.DealerList.Dealer.Name.content #returns "Randy's Rides"

Answer 1

To see what's wrong with a document use the errors method. After parsing your XML:

doc.errors
# => [#<Nokogiri::XML::SyntaxError: xmlns: URI www.example.com/ is not absolute>,
#     #<Nokogiri::XML::SyntaxError: XML declaration allowed only at the start of the document>,
#     #<Nokogiri::XML::SyntaxError: xmlns: URI www.example.com/SellerMessages is not absolute>]

To extract the data I'd use something like this:

doc = Nokogiri::XML(XML)
doc.remove_namespaces!
dealers = doc.search('Dealer').map{ |dealer|
  {
    buyer_id:       dealer.at( 'BUYER_ID'       ).text,
    reservation_id: dealer.at( 'Reservation_ID' ).text,
    name:           dealer.at( 'Name'           ).text
  }
}

dealers
# => [{:buyer_id=>"0000-2127",
#      :reservation_id=>
#       "1779853194|0000-2067|520a8037-57c8-497e-be4b-f4ea8dfa6c6f|14187-20",
#      :name=>"Randy's Rides"},
#     {:buyer_id=>"0000-2127",
#      :reservation_id=>
#       "1779853194|0000-2067|e42fd5c6-0a36-4552-8b6a-ad2decebd0db|14200-10",
#      :name=>"Jarrett's New Car Dealership 01"},
#     {:buyer_id=>"0000-2127",
#      :reservation_id=>
#       "1779853194|0000-2067|3fecb591-3a81-49f9-82b3-1f0d7fb3f7a6|14160-20",
#      :name=>"Campbell's Crazy Cars"},
#     {:buyer_id=>"0000-2127",
#      :reservation_id=>
#       "1779853194|0000-2067|731b09e9-700b-4f41-8cb0-eaf80e861d76|14158-7",
#      :name=>"Demo Dealer 3"}]

Of course you'll want to add/remove/change fields being extracted to fit your use-case.

Using slop mode has its dangers, as stated by the Nokogiri documentation .

1. Don't use this.
2. This may or may not be a backhanded compliment.
3. No, really, don't use this. If you use it, don't report bugs.
4. You've been warned!

I've never used it as a result. Often we don't want to use remove_namespaces! either, but it appears safe in your situation.