PHP | XMLReader isValid() Function Last Updated : 27 Mar, 2020 Summarize Comments Improve Suggest changes Share Like Article Like Report The XMLReader::isValid() function is an inbuilt function in PHP which is used to check if the document being parsed is valid or not. An XML is valid if it is written by following a DTD (Document Type Definition) which defines all the allowed elements and the structure of elements. Syntax: bool XMLReader::isValid( void ) Parameters: This function doesn’t accepts any parameter. Return Value: This function returns TRUE on success or FALSE on failure. Below given programs illustrate the XMLReader::isValid() function in PHP: Program 1: Filename: data.xml html <?xml version="1.0"?> <!-- DTD rules to be followed by XML--> <!DOCTYPE html [ <!ELEMENT html (h1, p, heading, body)> <!ELEMENT h1 (#PCDATA)> <!ELEMENT p (#PCDATA)> <!ELEMENT heading (#PCDATA)> <!ELEMENT body (#PCDATA)> ]> <!-- XML starts from here --> <html> <h1>Hi</h1> <p>World</p> <heading>GeeksforGeeks</heading> <body>Web Portal for Geeks</body> </html> Filename: index.php php <?php // Create a new XMLReader instance $XMLReader = new XMLReader(); // Open the XML file $XMLReader->open('data.xml'); // Enable the Parser Property $XMLReader->setParserProperty( XMLReader::VALIDATE, true); // Iterate through the XML nodes while ($XMLReader->read()) { if ($XMLReader->nodeType == XMLREADER::ELEMENT) { // Check if XML is valid or not $isValid = $XMLReader->isValid(); if ($isValid) { echo "YES ! this node is validated<br>"; } } } ?> Output: YES ! this node is validated YES ! this node is validated YES ! this node is validated YES ! this node is validated YES ! this node is validated Program 2: Filename: data.xml php <?xml version="1.0"?> <!-- DTD rules to be followed by XML--> <!DOCTYPE html [ <!ELEMENT html (heading, body)> <!ELEMENT heading (#PCDATA)> <!ELEMENT body (#PCDATA)> ]> <!-- XML starts from here --> <html> <body>Web Portal for Geeks</body> </html> Filename: index.php php <?php // Create a new XMLReader instance $XMLReader = new XMLReader(); // Open the XML file $XMLReader->open('data.xml'); // Enable the Parser Property $XMLReader->setParserProperty( XMLReader::VALIDATE, true); // Iterate through the XML nodes while ($XMLReader->read()) { if ($XMLReader->nodeType == XMLREADER::ELEMENT) { // Check if XML is valid or not $isValid = $XMLReader->isValid(); if (!$isValid) { echo "No ! this node is not validated<br>"; } } } ?> Output: No ! this node is not validated No ! this node is not validated Reference: https://www.php.net/manual/en/xmlreader.isvalid.php Comment More infoAdvertise with us Next Article PHP | XMLReader read() Function G gurrrung Follow Improve Article Tags : Web Technologies PHP PHP-function PHP-XML Similar Reads PHP | XMLReader next() Function The XMLReader::next() function is an inbuilt function in PHP which is used to move cursor to next node skipping all subtrees. Another usage of this function is it accepts the name of the node to directly move to the element.Syntax:  bool XMLReader::next( string $localname ) Parameters: This functio 2 min read PHP | XMLReader read() Function The XMLReader::read() function is an inbuilt function in PHP which is used to move to next node in document. Thus this function is used to traverse through the XML document. Syntax: bool XMLReader::read( void ) Parameters: This function doesn’t accepts any parameter. Return Value: This function retu 2 min read PHP | XMLReader moveToAttribute() Function The XMLReader::moveToAttribute() function is an inbuilt function in PHP which is used to move cursor to a named attribute. Syntax: bool XMLReader::moveToAttribute( string $name ) Parameters: This function accepts a single parameter $name which holds the name of the attribute. Return Value: This func 2 min read PHP | XMLReader moveToElement() Function The XMLReader::moveToElement() function is an inbuilt function in PHP which is used to move cursor to the parent element of current attribute. This function can be used to get the element having certain attributes by combining this with XMLReader::moveToAttribute() function. Syntax: bool XMLReader:: 2 min read PHP | XMLReader moveToAttributeNs() Function The XMLReader::moveToAttributeNs() function is an inbuilt function in PHP which is used to move cursor on the named attribute in specified namespace. This method is useful when we want to get the attribute value of a specific attribute in a specific namespace and ignore all other namespaces. Syntax: 2 min read PHP | XMLReader lookupNamespace() Function The XMLReader::lookupNamespace() function is an inbuilt function in PHP which is used to lookup in scope namespace for a given prefix. Syntax: string XMLReader::lookupNamespace( string $prefix ) Parameters: This function accepts a single parameter $prefix which holds the string containing the prefix 1 min read Like