Merge people profiles based on email match - php

Question

I have an existing directory (php with xml datasource) which contains people information such as this:
MainSource.xml
<people>
<person>
<id></id>
<last_name></last_name>
<first_name></first_name>
<email></email>
<phone></phone>
</person>
...
</people>
I need to add a new node to MainSource.xml from NewSource.xml, matching on email address, from the new datasource which contains people info like this:
NewSource.xml
<people>
<person>
<email></email>
<website_url></website_url>
</person>
...
</people>
I have tried a number of variations, but I think my hangup is properly comparing the two documents. Logically, it feels like I need to be iterating, as opposed to foreach? Or two foreach, one for each source? Here's a sample of what I'm thinking. Please offer any clarity or insight which can nudge me along in the right direction.
<?php
$doc1 = new DOMDocument();
$doc1->load('MainSource.xml');
$doc2 = new DOMDocument();
$doc2->load('NewSource.xml');
foreach ($doc1->person as $person) {
if ($person->email === $doc2->person->email) {
$node = $doc1->createElement("website_url", $valueFromDoc2);
$newnode = $doc1->appendChild($node);
}
}
$merged = $doc1->saveXML();
file_put_contents('MergedSource.xml', $merged)
?>

Answer 1

As mentioned by #waterloomatt, you need to use xpath to achieve that.
Assuming that MainSource.xml looks like this:
<people>
<person>
<id>1</id>
<last_name>smith</last_name>
<first_name>john</first_name>
<email>js#example.com</email>
<phone>555-123-1234</phone>
</person>
<person>
<id>2</id>
<last_name>doe</last_name>
<first_name>jane</first_name>
<email>jd#anotherexample.com</email>
<phone>666-234-2345</phone>
</person>
</people>
and NewSource.xml looks like this:
<people>
<person>
<email>js#example.com</email>
<website_url>js.example.com</website_url>
</person>
<person>
<email>jd#anotherexample.com</email>
<website_url>jd.anotherexample.com</website_url>
</person>
</people>
you can try this:
$doc1->loadXML('MainSource.xml');
$xpath1 = new DOMXPath($doc1);
# find each person's email address
$sources = $xpath1->query('//person//email');
$doc2->loadXML('NewSource.xml');
$xpath2 = new DOMXPath($doc2);
foreach ($sources as $source) {
#for each email address, get the parent and use that as the destination
#of the new web address element
$destination = $xpath1->query('..',$source);
#in the other doc, search for each person whose email address matches
#that of the first doc and get the relevant web address
$exp2 = "//person[email[text()='{$source->nodeValue}']]//website_url";
$target = $xpath2->query($exp2);
#import the result of the search as a node into the first doc
$node = $doc1->importNode($target[0], true);
#finally, append the imported node in the right location of the first doc
$destination[0]->appendChild($node);
};
echo $doc1->saveXml();
Output:
<people>
<person>
<id>1</id>
<last_name>smith</last_name>
<first_name>john</first_name>
<email>js#example.com</email>
<phone>555-123-1234</phone>
<website_url>js.example.com</website_url></person>
<person>
<id>2</id>
<last_name>doe</last_name>
<first_name>jane</first_name>
<email>jd#anotherexample.com</email>
<phone>666-234-2345</phone>
<website_url>jd.anotherexample.com</website_url></person>
</people>