Using xpath to query XML in PHP

Question

I am using xpath for the first time to query an xml document for a value and return the corresponding name value. I have been reading numerous different sources on the topic but I can't seem to get it to output correctly. Here is my XML :

<?xml version="1.0" encoding="utf-8"?>
<books>
  <book>
    <name>Genesis</name>
    <abrv>GEN</abrv>
    <title>The First Book of Moses</title>
  </book>
  <book>
    <name>Exodus</name>
    <abrv>EXO</abrv>
    <title>The Second Book of Moses</title>
  </book>
  <book>
    <name>Leviticus</name>
    <abrv>LEV</abrv>
    <title>The Third Book of Moses</title>
  </book>
</books>

Here is my PHP / HTML :

<?php $root = $_SERVER['DOCUMENT_ROOT'] . "/";
$bookID = 'GEN';
$xml = simplexml_load_file( $root . 'assets/xml/books.xml' ) or die( "No Page Data Found" );
$bookName = $xml->xpath( '//book[abrv="'.$bookID.'"]/name' );
?>
<article id="verseOfDay">
  <div class="container">
    <h2>verse of the day</h2>
    <h6><?php echo $bookName; ?></h6> // Line 19
    <p></p>
  </div>
</article>

Finally, here is the notice that I am receiving:

NOTICE: ARRAY TO STRING CONVERSION IN /HOME/#####/MYWEBSITE.COM/ASSETS/INCLUDES/VERSEOFTHEDAY.PHP ON LINE 19 ARRAY

What am I doing wrong? In this example I am expecting it to output Genesis in the tag.

Answer 1

The SimpleXML xpath function returns an array of results, which will be empty if no result is found. So you need to check for that, and if you get a result, it will be at $bookName[0] . Something like this will work:

$bookNames = $xml->xpath( '//book[abrv="'.$bookID.'"]/name' );
$bookName = empty($bookNames) ? 'Not Found' : $bookNames[0];
?>
<article id="verseOfDay">
  <div class="container">
    <h2>verse of the day</h2>
    <h6><?php echo $bookName; ?></h6>
    <p></p>
  </div>
</article>

Demo on 3v4l.org