Implement DOMElement::className

ref: https://dom.spec.whatwg.org/#dom-element-classname

Closes GH-11691.

NEWS

@@ -19,6 +19,7 @@ PHP                                                                        NEWS
   . Added DOMNode::contains() and DOMNameSpaceNode::contains(). (nielsdos)
   . Added DOMElement::getAttributeNames(). (nielsdos)
   . Added DOMNode::getRootNode(). (nielsdos)
+  . Added DOMElement::className. (nielsdos)
 
 - Intl:
   . Fix memory leak in MessageFormatter::format() on failure. (Girgias)

UPGRADING

@@ -252,6 +252,8 @@ PHP 8.3 UPGRADE NOTES
   . Added DOMNode::getRootNode(). The $options argument does nothing at the
     moment because it only influences the shadow DOM, which we do not support
     yet.
+  . Added DOMElement::className. This is not binary-safe at the moment
+    because of underlying limitations of libxml2.
 
 - JSON:
   . Added json_validate(), which returns whether the json is valid for

ext/dom/dom_properties.h

@@ -71,6 +71,8 @@ int dom_documenttype_internal_subset_read(dom_object *obj, zval *retval);
 
 /* element properties */
 int dom_element_tag_name_read(dom_object *obj, zval *retval);
+int dom_element_class_name_read(dom_object *obj, zval *retval);
+int dom_element_class_name_write(dom_object *obj, zval *newval);
 int dom_element_schema_type_info_read(dom_object *obj, zval *retval);
 
 /* entity properties */

ext/dom/element.c

@@ -137,6 +137,55 @@ int dom_element_tag_name_read(dom_object *obj, zval *retval)
 
 /* }}} */
 
+/* {{{ className	string
+URL: https://dom.spec.whatwg.org/#dom-element-classname
+Since:
+*/
+int dom_element_class_name_read(dom_object *obj, zval *retval)
+{
+	xmlNodePtr nodep = dom_object_get_node(obj);
+
+	if (nodep == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 1);
+		return FAILURE;
+	}
+
+	xmlChar *content = xmlGetNoNsProp(nodep, (const xmlChar *) "class");
+	if (content == NULL) {
+		ZVAL_EMPTY_STRING(retval);
+		return SUCCESS;
+	}
+
+	ZVAL_STRING(retval, (const char *) content);
+	xmlFree(content);
+
+	return SUCCESS;
+}
+
+int dom_element_class_name_write(dom_object *obj, zval *newval)
+{
+	xmlNode *nodep = dom_object_get_node(obj);
+
+	if (nodep == NULL) {
+		php_dom_throw_error(INVALID_STATE_ERR, 1);
+		return FAILURE;
+	}
+
+	if (dom_node_is_read_only(nodep) == SUCCESS) {
+		php_dom_throw_error(NO_MODIFICATION_ALLOWED_ERR, dom_get_strict_error(obj->document));
+		return FAILURE;
+	}
+
+	/* Typed property, so it is a string already */
+	ZEND_ASSERT(Z_TYPE_P(newval) == IS_STRING);
+	xmlSetProp(nodep, (const xmlChar *) "class", (const xmlChar *) Z_STRVAL_P(newval));
+
+	php_libxml_invalidate_node_list_cache_from_doc(nodep->doc);
+
+	return SUCCESS;
+}
+/* }}} */
+
 /* {{{ schemaTypeInfo	typeinfo
 readonly=yes
 URL: http://www.w3.org/TR/2003/WD-DOM-Level-3-Core-20030226/DOM3-Core.html#Element-schemaTypeInfo

ext/dom/php_dom.c

@@ -751,6 +751,7 @@ PHP_MINIT_FUNCTION(dom)
 
 	zend_hash_init(&dom_element_prop_handlers, 0, NULL, dom_dtor_prop_handler, 1);
 	dom_register_prop_handler(&dom_element_prop_handlers, "tagName", sizeof("tagName")-1, dom_element_tag_name_read, NULL);
+	dom_register_prop_handler(&dom_element_prop_handlers, "className", sizeof("className")-1, dom_element_class_name_read, dom_element_class_name_write);
 	dom_register_prop_handler(&dom_element_prop_handlers, "schemaTypeInfo", sizeof("schemaTypeInfo")-1, dom_element_schema_type_info_read, NULL);
 	dom_register_prop_handler(&dom_element_prop_handlers, "firstElementChild", sizeof("firstElementChild")-1, dom_parent_node_first_element_child_read, NULL);
 	dom_register_prop_handler(&dom_element_prop_handlers, "lastElementChild", sizeof("lastElementChild")-1, dom_parent_node_last_element_child_read, NULL);

ext/dom/php_dom.stub.php

@@ -542,6 +542,8 @@ class DOMElement extends DOMNode implements DOMParentNode, DOMChildNode
     /** @readonly */
     public string $tagName;
 
+    public string $className;
+
     /** @readonly */
     public mixed $schemaTypeInfo = null;
 

ext/dom/tests/DOMElement_className.phpt

@@ -0,0 +1,47 @@
+--TEST--
+DOMElement::className
+--EXTENSIONS--
+dom
+--FILE--
+<?php
+
+class MyStringable {
+    public function __toString(): string {
+        throw new Exception("foo");
+    }
+}
+
+$dom = new DOMDocument();
+$dom->loadXML('<html/>');
+
+var_dump($dom->documentElement->className);
+$dom->documentElement->className = "hello & world<>";
+var_dump($dom->documentElement->className);
+$dom->documentElement->className = "";
+var_dump($dom->documentElement->className);
+$dom->documentElement->className = "é";
+var_dump($dom->documentElement->className);
+$dom->documentElement->className = "\0";
+var_dump($dom->documentElement->className);
+$dom->documentElement->className = 12345;
+var_dump($dom->documentElement->className);
+try {
+    $dom->documentElement->className = new MyStringable();
+} catch (Throwable $e) {
+    echo "Error: ", $e->getMessage(), "\n";
+}
+var_dump($dom->documentElement->className);
+echo $dom->saveXML();
+
+?>
+--EXPECT--
+string(0) ""
+string(15) "hello & world<>"
+string(0) ""
+string(2) "é"
+string(0) ""
+string(5) "12345"
+Error: foo
+string(5) "12345"
+<?xml version="1.0"?>
+<html class="12345"/>

ext/dom/tests/bug69846.phpt

@@ -78,11 +78,13 @@ object(DOMText)#%d (21) {
   string(3) "
   "
 }
-object(DOMElement)#7 (23) {
+object(DOMElement)#7 (24) {
   ["schemaTypeInfo"]=>
   NULL
   ["tagName"]=>
   string(5) "form1"
+  ["className"]=>
+  string(0) ""
   ["firstElementChild"]=>
   string(22) "(object value omitted)"
   ["lastElementChild"]=>

ext/dom/tests/bug80602_3.phpt

@@ -21,11 +21,13 @@ var_dump($target);
 ?>
 --EXPECTF--
 <a>barfoobaz<last/></a>
-object(DOMElement)#3 (23) {
+object(DOMElement)#3 (24) {
   ["schemaTypeInfo"]=>
   NULL
   ["tagName"]=>
   string(4) "last"
+  ["className"]=>
+  string(0) ""
   ["firstElementChild"]=>
   NULL
   ["lastElementChild"]=>
@@ -70,11 +72,13 @@ object(DOMElement)#3 (23) {
   string(0) ""
 }
 <a><last/>barfoobaz</a>
-object(DOMElement)#2 (23) {
+object(DOMElement)#2 (24) {
   ["schemaTypeInfo"]=>
   NULL
   ["tagName"]=>
   string(4) "last"
+  ["className"]=>
+  string(0) ""
   ["firstElementChild"]=>
   NULL
   ["lastElementChild"]=>