XML parsing with XPath and PHP handle empty values

Question

while parsing through a XML tree like this:

<vco:ItemDetail>
    <cac:Item>
        <cbc:Description>ROLLENKERNSATZ 20X12 MM 10,5 GR.</cbc:Description>
        <cac:SellersItemIdentification>
            <cac:ID>78392636</cac:ID>
        </cac:SellersItemIdentification>
        <cac:ManufacturersItemIdentification>
            <cac:ID>RMS100400370</cac:ID>
            <cac:IssuerParty>
               <cac:PartyName>
                   <cbc:Name></cbc:Name>
               </cac:PartyName>
            </cac:IssuerParty>
        </cac:ManufacturersItemIdentification>
    </cac:Item>
    <vco:Availability>
       <vco:Code>available</vco:Code>
    </vco:Availability>
</vco:ItemDetail>

I always get a blank space which breaks my CSV structure if cbc:Name is empty, which looks like this:

"ROLLENKERNSATZ 20X12 MM 10,5 GR.";78392636;;RMS100400370;"";available

The "available" string is in a new line so my CSV is not structered any more.

My XPath array looks like this:

$columns = array('Description' => 'string(cac:Item/cbc:Description)',
          'SellersItemIdentification' => 'string(cac:Item/cac:SellersItemIdentification/cac:ID)',
          'StandardItemIdentification' => 'string(cac:Item/cac:StandardItemIdentification/cac:ID)',
          'Availability' => 'string(vco:Availability/vco:Code)',
          'Producer' => 'string(cac:Item/cac:ManufacturersItemIdentification/cac:IssuerParty/cac:PartyName/cbc:Name');

Is there any expception or replacement I can handle with like replacing the empty node value with "no producer" or something like this?

Thank you

Answer 1

If the value to use as the 'default' can somehow be made to exist somewhere in your input document, the problem can be solved with a quasi-coalesce like this:

eg

<vco:ItemDetail xmlns:vco="x1" xmlns:cac="x2" xmlns:cbc="x3">
   <ValueIfNoProducer>No Producer</ValueIfNoProducer>
   <cac:Item>
      ...

Then this Xpath 1.0 will apply a default if the Name element is empty or whitespace:

(cac:Item/cac:ManufacturersItemIdentification/cac:IssuerParty
     /cac:PartyName/cbc:Name[normalize-space(.)] | ValueIfNoProducer)[1]

I think the following is possible directly in XPath 2.0, but I stand to be corrected:

(cac:Item/cac:ManufacturersItemIdentification/cac:IssuerParty
     /cac:PartyName/cbc:Name[normalize-space(.)] | 'No Producer')[1]