XML Tutorial · XML in Code · Lesson 18 of 28

XML in PHP

SimpleXML for quick reading, DOMDocument and DOMXPath for full control, and XMLWriter and XMLReader for large documents.

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Which API?

API	Best for
SimpleXML	Reading small, simple documents with object syntax (`$order->item[0]['sku']`)
DOMDocument + DOMXPath	Full control: namespaces, editing, XPath, validation
XMLWriter	Writing large documents piece by piece
XMLReader	Reading large documents as a stream

All are built on libxml2 and usually enabled by default. PHP 8 and libxml2 2.9+ don't load external entities unless you pass LIBXML_NOENT, which keeps the defaults safe (see XML security).

SimpleXML

Read with SimpleXMLTry it yourself

<?php
$shop = simplexml_load_string('<shop>
  <product sku="TEA-01" category="drinks"><name>Green tea</name><price>3.50</price><stock>40</stock></product>
  <product sku="COF-02" category="drinks"><name>Coffee beans</name><price>9.90</price><stock>0</stock></product>
  <product sku="MUG-07" category="kitchen"><name>Camel mug</name><price>12.00</price><stock>15</stock></product>
  <product sku="PAN-03" category="kitchen"><name>Frying pan</name><price>29.00</price><stock>4</stock></product>
</shop>');
foreach ($shop->product as $p) {
    printf("%-7s %-13s %6.2f\n", $p['sku'], $p->name, (float) $p->price);
}
$kitchen = $shop->xpath("//product[@category='kitchen']/name");
echo "kitchen: ", implode(", ", array_map('strval', $kitchen)), "\n";
echo "first price: ", $shop->product[0]->price, "\n";

Output

TEA-01  Green tea       3.50
COF-02  Coffee beans    9.90
MUG-07  Camel mug      12.00
PAN-03  Frying pan     29.00
kitchen: Camel mug, Frying pan
first price: 3.50

DOMDocument

Edit with DOMDocumentTry it yourself

<?php
$doc = new DOMDocument();
$doc->preserveWhiteSpace = false;
$doc->loadXML('<shop>
  <product sku="TEA-01" category="drinks"><name>Green tea</name><price>3.50</price><stock>40</stock></product>
  <product sku="COF-02" category="drinks"><name>Coffee beans</name><price>9.90</price><stock>0</stock></product>
  <product sku="MUG-07" category="kitchen"><name>Camel mug</name><price>12.00</price><stock>15</stock></product>
  <product sku="PAN-03" category="kitchen"><name>Frying pan</name><price>29.00</price><stock>4</stock></product>
</shop>');
$xp = new DOMXPath($doc);

foreach ($xp->query("//product[stock = 0]") as $p) {
    $p->parentNode->removeChild($p);
}
$new = $doc->createElement("product");
$new->setAttribute("sku", "SPN-11");
$new->appendChild($doc->createElement("name", "Wooden spoon"));
$doc->documentElement->appendChild($new);

echo $xp->evaluate("count(//product)"), " products\n";
$doc->formatOutput = true;
echo $doc->saveXML($new);

Output

4 products
<product sku="SPN-11">
  <name>Wooden spoon</name>
</product>

XMLWriter

Write with XMLWriterTry it yourself

<?php
$w = new XMLWriter();
$w->openMemory();
$w->setIndent(true);
$w->startDocument("1.0", "UTF-8");
$w->startElement("feed");
foreach (["Tea & cake", "Coffee <beans>"] as $i => $title) {
    $w->startElement("entry");
    $w->writeAttribute("id", (string) ($i + 1));
    $w->writeElement("title", $title);   // escaped automatically
    $w->endElement();
}
$w->endElement();
echo $w->outputMemory();

Output

<?xml version="1.0" encoding="UTF-8"?>
<feed>
 <entry id="1">
  <title>Tea &amp; cake</title>
 </entry>
 <entry id="2">
  <title>Coffee &lt;beans&gt;</title>
 </entry>
</feed>

Test yourself

Which PHP API reads very large XML files without loading them into memory?

XMLReader
SimpleXML
DOMDocument
json_decode

Show answer

Answer: XMLReader

XMLReader is a pull parser that moves through the document node by node.