input xml file to php with multiple elements in a element? - php

Question

Hello i am having much trouble inputting the following XML because of the multiple "authors" .. it works when i try with 1 but with multiple it fails. does anyone know how i can do the multiple author input? below is my an example of the xml and code
<pub>
<ID>3</ID>
<title>A Sampling Based Approach to Facial Feature Extraction</title>
<year>2005</year>
<booktitle>AutoID</booktitle>
<pages>51-56</pages>
<authors>
<author>john johnson</author>
<author>billy bob</author>
</authors>
</pub>
my code:
<?php
$pubs = new SimpleXMLElement('p.xml', null, true);
echo <<<EOF
<table>
<tr>
<th>ID</th>
<th>title</th>
<th>year</th>
<th>booktitle</th>
<th>pages</th>
<th>authors</th>
</tr>
EOF;
foreach($pubs as $pub)
{
echo <<<EOF
<tr>
<td>{$pub->ID}</td>
<td>{$pub->title}</td>
<td>{$pub->year}</td>
<td>{$pub->booktitle}</td>
<td>{$pub->pages}</td>
<td>{$pub->authors}</td>
</tr>
EOF;
}
echo '</table>';
?>

Answer 1

The authors are a several nodes, so you have to use a second loop. Additionally if you output values in HTML/XML, you need to escape them. htmlspecialchars() does a good enough job for that.
You're transforming XML into HTML here. XSLT would be a better tool for that. It is supported by the XSL extension in PHP.
In PHP you can use Xpath to extract data from XML:
$dom = new DOMDocument();
$dom->load('p.xml');
$xpath = new DOMXpath($dom);
echo <<<EOF
<table>
<tr>
<th>ID</th>
<th>title</th>
<th>year</th>
<th>booktitle</th>
<th>pages</th>
<th>authors</th>
</tr>
EOF;
$pubs = $xpath->evaluate('//pub');
foreach($pubs as $pub) {
echo '<tr>', "\n";
echo '<td>', htmlspecialchars($xpath->evaluate('string(./ID)', $pub)), '</td>', "\n";
echo '<td>', htmlspecialchars($xpath->evaluate('string(./title)', $pub)), '</td>', "\n";
echo '<td>', htmlspecialchars($xpath->evaluate('string(./year)', $pub)), '</td>', "\n";
echo '<td>', htmlspecialchars($xpath->evaluate('string(./booktitle)', $pub)), '</td>', "\n";
echo '<td>', htmlspecialchars($xpath->evaluate('string(./pages)', $pub)), '</td>', "\n";
// fetch all the authors into an array
$authors = array();
foreach ($xpath->evaluate('./authors/author', $pub) as $author) {
$authors[] = $author->nodeValue;
}
echo '<td>'.htmlspecialchars(implode(', ', $authors)).'</td>', "\n";
echo '</tr>', "\n";
}
echo '</table>';
The example uses DOMXpath::evaluate() because it allows to query string directly from the DOM. $xpath->evaluate('string(./ID)', $pub) returns the text content inside the ID child of the context node $pub, or an empty string if here is no child element ID.

Answer 2

The simpliest way, i think, is to convert it to json string than back to array and you will see that is an array so you will need another foreach
$pubs = new SimpleXMLElement('p.xml', null, true);
$jsonString = json_encode($pubs);
$assocArray = json_decode($jsonString, true);
echo '<pre>';
var_dump($assocArray);
echo '</pre>';
Sorry. I give you wrong informations, because if you tried this code you will get different result if you have more than 1 '' tags and if you have only 1.
So i have another solution:
<?php
$pubs = new SimpleXMLElement('test.xml', null, true);
echo <<<EOF
<table>
<tr>
<th>ID</th>
<th>title</th>
<th>year</th>
<th>booktitle</th>
<th>pages</th>
<th>authors</th>
</tr>
EOF;
$pubsXpath = $pubs->xpath('//pub');
/** #var SimpleXMLElement $pub */
foreach ($pubsXpath as $pub) {
$authorsSxml = $pub->xpath('authors/author');
$authors = join(', ', $authorsSxml);
echo <<<EOF
<tr>
<td>{$pub->ID}</td>
<td>{$pub->title}</td>
<td>{$pub->year}</td>
<td>{$pub->booktitle}</td>
<td>{$pub->pages}</td>
<td>{$authors}</td>
</tr>
EOF;
}
echo '</table>';
?>