How check if a String is a Valid XML with-out Displaying a Warning in PHP

Xml Problem Overview

i was trying to check the validity of a string as xml using this simplexml_load_string()^Docs function but it displays a lot of warning messages.

How can I check whether a string is a valid XML without suppressing (@ at the beginning) the error and displaying a warning function that expec

Xml Solutions

Solution 1 - Xml

> Use libxml_use_internal_errors() to suppress all XML errors, and libxml_get_errors() to iterate over them afterwards.

Simple XML loading string

libxml_use_internal_errors(true);

$doc = simplexml_load_string($xmlstr);
$xml = explode("\n", $xmlstr);

if (!$doc) {
    $errors = libxml_get_errors();

    foreach ($errors as $error) {
        echo display_xml_error($error, $xml);
    }

    libxml_clear_errors();
}

Solution 2 - Xml

From the documentation:

> Dealing with XML errors when loading documents is a very simple task. Using the libxml functionality it is possible to suppress all XML errors when loading the document and then iterate over the errors. > >The libXMLError object, returned by libxml_get_errors(), contains several properties including the message, line and column (position) of the error.

libxml_use_internal_errors(true);
$sxe = simplexml_load_string("<?xml version='1.0'><broken><xml></broken>");
if (!$sxe) {
    echo "Failed loading XML\n";
    foreach(libxml_get_errors() as $error) {
        echo "\t", $error->message;
    }
}

Reference: libxml_use_internal_errors

Solution 3 - Xml

try this one

//check if xml is valid document
public function _isValidXML($xml) {
    $doc = @simplexml_load_string($xml);
    if ($doc) {
        return true; //this is valid
    } else {
        return false; //this is not valid
    }
}

Solution 4 - Xml

My version like this:

//validate only XML. HTML will be ignored.

function isValidXml($content)
{
    $content = trim($content);
    if (empty($content)) {
        return false;
    }
    //html go to hell!
	if (stripos($content, '<!DOCTYPE html>') !== false) {
		return false;
	}

	libxml_use_internal_errors(true);
	simplexml_load_string($content);
	$errors = libxml_get_errors();		    
	libxml_clear_errors();	
	
    return empty($errors);
}

Tests:

//false
var_dump(isValidXml('<!DOCTYPE html><html><body></body></html>'));
//true
var_dump(isValidXml('<?xml version="1.0" standalone="yes"?><root></root>'));
//false
var_dump(isValidXml(null));
//false
var_dump(isValidXml(1));
//false
var_dump(isValidXml(false));
//false
var_dump(isValidXml('asdasds'));

Solution 5 - Xml

Here a small piece of class I wrote a while ago:

/**
 * Class XmlParser
 * @author Francesco Casula <fra.casula@gmail.com>
 */
class XmlParser
{
    /**
     * @param string $xmlFilename Path to the XML file
     * @param string $version 1.0
     * @param string $encoding utf-8
     * @return bool
     */
    public function isXMLFileValid($xmlFilename, $version = '1.0', $encoding = 'utf-8')
    {
        $xmlContent = file_get_contents($xmlFilename);
        return $this->isXMLContentValid($xmlContent, $version, $encoding);
    }

    /**
     * @param string $xmlContent A well-formed XML string
     * @param string $version 1.0
     * @param string $encoding utf-8
     * @return bool
     */
    public function isXMLContentValid($xmlContent, $version = '1.0', $encoding = 'utf-8')
    {
        if (trim($xmlContent) == '') {
            return false;
        }

        libxml_use_internal_errors(true);

        $doc = new DOMDocument($version, $encoding);
        $doc->loadXML($xmlContent);

        $errors = libxml_get_errors();
        libxml_clear_errors();

        return empty($errors);
    }
}

It works fine with streams and vfsStream as well for testing purposes.

Solution 6 - Xml

Case

Occasionally check availability of a Google Merchant XML feed.

The feed is without DTD, so validate() won't work.

Solution

// disable forwarding those load() errors to PHP
libxml_use_internal_errors(true);
// initiate the DOMDocument and attempt to load the XML file
$dom = new \DOMDocument;
$dom->load($path_to_xml_file);
// check if the file contents are what we're expecting them to be
// `item` here is for Google Merchant, replace with what you expect
$success = $dom->getElementsByTagName('item')->length > 0;
// alternatively, just check if the file was loaded successfully
$success = null !== $dom->actualEncoding;

length above contains a number of how many products are actually listed in the file. You can use your tag names instead.

Logic

You can call getElementsByTagName() on any other tag names (item I used is for Google Merchant, your case may vary), or read other properties on the $dom object itself. The logic stays the same: instead of checking if there were errors when loading the file, I believe actually trying to manipulate it (or specifically check if it contains the values you actually need) would be more reliable.

Most important: unlike validate(), this won't require your XML to have a DTD.

Solution 7 - Xml

Solution

<?php
/**
* 檢查XML是否正確
* 
* @param string $xmlstr
* @return bool
*/
public function checkXML($xmlstr)
{
    libxml_use_internal_errors(true);
    $doc = simplexml_load_string($xmlstr);
    if (!$doc) {
        $errors = libxml_get_errors();
        if (count($errors)) {
            libxml_clear_errors();
            return false;
        }
    }
    return true;
}

Content Type	Original Author	Original Content on Stackoverflow
Question	jspeshu	View Question on Stackoverflow
Solution 1 - Xml	Tjirp	View Answer on Stackoverflow
Solution 2 - Xml	Felix Kling	View Answer on Stackoverflow
Solution 3 - Xml	Jkhaled	View Answer on Stackoverflow
Solution 4 - Xml	admin	View Answer on Stackoverflow
Solution 5 - Xml	Francesco Casula	View Answer on Stackoverflow
Solution 6 - Xml	mehov	View Answer on Stackoverflow
Solution 7 - Xml	kkasp	View Answer on Stackoverflow