(Perl) Find and Update an XML Attribute Value

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Demonstrates how to find an element in XML with a specified attribute name and then update the attribute value.

Chilkat Perl Downloads Perl Module for Windows, MacOS, Linux, Alpine Linux, Solaris

use chilkat();

# Let's say you have 2 XML files with identical structures as shown directly below,
# and you wish to update the values in the 1st XML file with those in the 2nd XML file.

# <global>
#     <phrase id="2FADisabled" value="2factor authentication disabled"/>
#     <phrase id="2FAEnabled" value="2factor authentication enabled"/>
#     <phrase id="2FAResetFailed" value="Failed to disable two factor authentication"/>
# </global>

# <global>
#     <phrase id="2FAResetFailed" value="Failed to reset two factor authentication"/>
#     <phrase id="2FADisabled" value="2FA authentication disabled"/>
#     <phrase id="2FAEnabled" value="2FA authentication enabled"/>
# </global>

# First, initialize each of the Chilkat XML objects.
# These could be loaded from files, but we'll just create them manually for this example..

$xml1 = chilkat::CkXml->new();
$xml1->put_Tag("global");
$xml1->UpdateAttrAt("phrase",1,"id","2FADisabled");
$xml1->UpdateAttrAt("phrase",1,"value","2factor authentication disabled");
$xml1->UpdateAttrAt("phrase[1]",1,"id","2FAEnabled");
$xml1->UpdateAttrAt("phrase[1]",1,"value","2factor authentication enabled");
$xml1->UpdateAttrAt("phrase[2]",1,"id","2FAResetFailed");
$xml1->UpdateAttrAt("phrase[2]",1,"value","Failed to disable two factor authentication");

$xml2 = chilkat::CkXml->new();
$xml2->put_Tag("global");
$xml2->UpdateAttrAt("phrase",1,"id","2FAResetFailed");
$xml2->UpdateAttrAt("phrase",1,"value","Failed to reset two factor authentication");
$xml2->UpdateAttrAt("phrase[1]",1,"id","2FADisabled");
$xml2->UpdateAttrAt("phrase[1]",1,"value","2FA authentication disabled");
$xml2->UpdateAttrAt("phrase[2]",1,"id","2FAEnabled");
$xml2->UpdateAttrAt("phrase[2]",1,"value","2FA authentication enabled");

# Iterate over attribute values in xml2 and update the same in xml1.

$sbPath = chilkat::CkStringBuilder->new();

$i = 0;
$count_i = $xml2->NumChildrenHavingTag("phrase");
while ($i < $count_i) {
    $xml2->put_I($i);
    $phrase_id = $xml2->chilkatPath("phrase[i]|(id)");
    $phrase_value = $xml2->chilkatPath("phrase[i]|(value)");

    # Notice how the UpdateAttrAt method's 1st argument is a Chilkat path -- which is an expression
    # to find the location of the XML element to be updated.
    # Here we create a path of the form "/A/tagName,attributeName,attributeValuePattern", which means
    # find the direct descendent of xml2 having tag=tagName, with an attribute=attributeName where the attribute value
    # matches the attributeValuePattern.  If attributeValuePattern does not contain a "*", then it must match directly.
    # We'll build a Chilkat path such as "/A/phrase,id,2FADisabled"
    $sbPath->SetString("/A/phrase,id,");
    $sbPath->Append($phrase_id);

    # This assumes the corresponding element exists in xml1.
    $xml1->UpdateAttrAt($sbPath->getAsString(),1,"value",$phrase_value);

    $i = $i + 1;
}

# Now see how xml1 has been updated..
print $xml1->getXml() . "\r\n";