in reply to Re^5: Xpath value query
in thread Xpath value query

So, I tried to use a variable to return the values from the XPath, and it's not liking it.. I get an invalid query error. Here is the subroutine I'm using. I must be missing something. I added a few statements to help me see what was happening. The goal is for the XPaths to come from a configuration file (as there are about a dozen, and there are other formats that will be added in the future so there may be hundreds ultimatley) rather than hard coded, but for testing and development I'm doing it this way.

$twig = XML::Twig::XPath->new();
$twig->parsefile($xmlfile);
$root = $twig->root;

$XPV='//Party[@id=//Relation[child::RelationRoleCode[@tc="37"]]/@Relat
+edObjectID]/Producer/CarrierAppointment/CompanyProducerID';
my $retval1 = get_xpath_value($XPV);
$XPV='//OLifE/Party[@id=//OLifE/Relation[RelationRoleCode@tc=8]/@Relat
+edObjectID]/Person/FirstName';
my $retval2 = get_xpath_value($XPV);
print "CompanyProducerID: $retval1 \nFirstName: $retval2\n";

sub get_xpath_value {

   my ($argvalx) = @_;
   print "argvalx: $argvalx\n";
   my $xpath = "q!" . $argvalx . "!";
   print "doing XPATH query on $xpath\n";
   my @nodes = $root->findnodes($xpath);
   for (@nodes){
     print $_->text;
     return $_->text;
   }
}


./twig4.pl -xmlfile=a2b9f375-51fe-41a1-86ab-069561517890.xml
argvalx: //Party[@id=//Relation[child::RelationRoleCode[@tc="37"]]/@Re
+latedObjectID]/Producer/CarrierAppointment/CompanyProducerID
doing XPATH query on q!//Party[@id=//Relation[child::RelationRoleCode[
+@tc="37"]]/@RelatedObjectID]/Producer/CarrierAppointment/CompanyProdu
+cerID!
Query:
q!//Party...
^^^
Invalid query somewhere around here (I think)

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Re^7: Xpath value query
by poj (Abbot) on Sep 18, 2015 at 18:03 UTC

    This was one problem, you don't need to my $xpath = "q!" . $argvalx . "!";

    see http://perldoc.perl.org/perlop.html#Quote-Like-Operators

    and the second XPATH was missing a [] here [@tc="8"]].
    Assuming you will only get a single match try 

    #!perl
use strict;
use XML::Twig::XPath;

my $xmlfile = $ARGV[0] || 'txlife.xml';

my $twig = XML::Twig::XPath->new();
$twig->parsefile($xmlfile);
my $root = $twig->root;

my @XPV = ();
$XPV[0] = '//Party[@id=//Relation[child::RelationRoleCode[@tc="37"]]/@
+RelatedObjectID]/Producer/CarrierAppointment/CompanyProducerID';
$XPV[1] = '//OLifE/Party[@id=//OLifE/Relation[RelationRoleCode[@tc=8]]
+/@RelatedObjectID]/Person/FirstName';

for my $i (0..1){
  my ($name,$value) = get_xpath_value($XPV[$i]);
  print "   $name : $value\n";
}

sub get_xpath_value {
   my ($xpath) = @_;   
   my @nodes = $root->findnodes($xpath);
   my $value = $nodes[0]->text;
   my $name  = $nodes[0]->getName;
   return ($name,$value);
}

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    Update : added getName and simplified
    poj
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      My most humble thanks.. I think that get's me exactly what I need to make this work.

      What I don't understand I guess is why in the original example you surrounded the XPath string with the q!..!? Just curious, I realize it doesn't matter with this solution.

      again, thanks.

[reply]

        because you had single quotes in [@tc='37'] in the query I couldn't just use ' query '.

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Re^7: Xpath value query (xpather not afraid of whitespace)
by Anonymous Monk on Sep 18, 2015 at 22:00 UTC
    FWIW, xpather.pl, and xpath is also not afraid of whitespace 
    $XPV[1] = q{
//Party[
    @id = //Relation[
                child::RelationRoleCode[
                    @tc="37"
                ]
          ]
          /@RelatedObjectID
]
/Producer/CarrierAppointment/CompanyProducerID
};
$XPV[1] = q{
//OLifE/Party[
        @id=//OLifE
            /Relation[
                RelationRoleCode[
                    @tc=8
                ]
            ]
            /@RelatedObjectID
    ]
    /Person/FirstName
};

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