Joomla5- php 8.1 error Attempted to load class "DOMDocument" - SOLVED

Detail: PHP 7.3 SUCCESS, PHP 8.1 + 8.2 error "DOMDocument"
Error: php 8.1 Attempted to load class "DOMDocument" from the global namespace.Did you forget a "use" statement?

Solution: CPANEL goto PHP Selector > extension check XML package checked all

 

Issue joomla Content-Security-Policy blocked a JavaScript .htaccess SOLVED

Browser error: Content-Security-Policy: The page’s settings blocked a JavaScript eval (script-src) from being executed because it violates the following directive: “script-src 'self' 'unsafe-inline' ...

Reason: host setting or .htaccess block scripts

Solutions: solution 1 or 2
Solution 1: .htaccess check example line

#Header set Content-Security-Policy "script-src 'self' 'unsafe-inline' https://cdn.ckeditor.com https://ajax.googleapis.com/ https://cdn.jsdelivr.net https://js.calltrk.com/ https://birdeye.com/ https://cdn.calltrk.com/ https://www.google-analytics.com/ https://widgets-v7.birdeye.com/ https://www.googletagmanager.com/ https://portal.setmysite.com/; object-src 'none';"

Remove or disable this line

Solution 2: .htaccess admin line s
<IfModule mod_headers.c>
Header always set Content-Security-Policy "script-src 'none'"
</IfModule>

 

 

.htaccess rewrite rule change '/' to '?'

Details: .htaccess rewrite rule change '/' to '?'
http://mydomain.com/myservices/support
to
http://mydomain.com/myservices?support
 

Solution:
<IfModule mod_rewrite.c>
    RewriteRule ^myservices/(.*)$ /myservices?$1 [R=301,NC,L]
</IfModule>

PHP - Get Country Code by live IP

Detail: function in region area or coutry
Solution: PHP get live IP from browser, get from http://www.geoplugin.net/json.gp?ip=1.2.3.4

<?php
// PHP code to obtain country, city,
// continent, etc using IP Address
 
//$ip = '52.25.109.230';
$ip= $_SERVER [ "REMOTE_ADDR" ];
 
// Use JSON encoded string and converts
// it into a PHP variable
$ipdat = @json_decode(file_get_contents(
    "http://www.geoplugin.net/json.gp?ip=" . $ip));
//print_r($ipdat);
echo 'Your IP: ' . $ip . "<br/>";
echo 'Country Name: ' . $ipdat->geoplugin_countryName . "<br/>";
echo 'Country code: ' . $ipdat->geoplugin_countryCode . "<br/>";
echo 'City Name: ' . $ipdat->geoplugin_city . "<br/>";
echo 'Continent Name: ' . $ipdat->geoplugin_continentName . "<br/>";
echo 'Latitude: ' . $ipdat->geoplugin_latitude . "<br/>";
echo 'Longitude: ' . $ipdat->geoplugin_longitude . "<br/>";
echo 'Currency Symbol: ' . $ipdat->geoplugin_currencySymbol . "<br/>";
echo 'Currency Code: ' . $ipdat->geoplugin_currencyCode . "<br/>";
echo 'Timezone: ' . $ipdat->geoplugin_timezone;
?>


PHP string Serialize Corrector SOLVED

Reason: many string Serialize NOT right format
Solution: check and correction  string. Check many times on internet
Source : from internet. Not remember exactly. So thanks for all

 /*Serialize Corrector*/
 function serialize_corrector($serialized_string){       
        if ( @unserialize($serialized_string) !== true &&  preg_match('/^[aOs]:/', $serialized_string) ) {
             $serialized_string = preg_replace_callback( '/s\:(\d+)\:\"(.*?)\";/s',    function($matches){return 's:'.strlen($matches[2]).':"'.$matches[2].'";'; },   $serialized_string );
        }
        return $serialized_string;
    }

PHP random array unique multi SOLVED

/*Original Array*/
$arrayIDs = ['a','aa','bb','cc'];
/*Result*/
$randomArray = [];
/*number unique*/
$numberRandom = 4;
if(count($arrayIDs)> $numberRandom){
while(count($randomArray) < $numberRandom) {
  $randomKey = mt_rand(0, count($arrayIDs)-1);
  $randomArray[$randomKey] = $arrayIDs[$randomKey];
}
}else{
$randomArray = $arrayIDs;
}

PHP HTML special decode textarea

Description: load data have htmlspecialchars, example: html char, new line, special char.... This need decode 1 again.
Solution: decode again htmlspecialchars_decode at PHP load.
More: At prevent sql rejection $_POST have special char at Textarea. This need encode to safe data.

<php? 
echo htmlspecialchars_decode($product['COLUMN_DATA']);
?>

Php the best way prevent SQL Injection

Description: hacker add query sql to input _POST, _GET param. So need clean each input value.
Solution: Filter all  _POST, _GET param. 2 case:
#Case 1: Number, String with htmlspecialchars.
#Case 2: _Post as array - Multi select box need array_walk_recursive check each item.
The code will convert all special character to UTF-8.
<?php
/*prevent Sql Injection*/
function _CleanInputChars(&$value){
    return htmlspecialchars($value, ENT_QUOTES, 'UTF-8');
}
foreach ($_POST as $key => $value) {
/*Array*/
if(is_array($value)){
array_walk_recursive($value, "_CleanInputChars");
}
else{
/*Number,String*/
$_POST[$key] = _CleanInputChars($value);
}
}
foreach ($_GET as $key => $value) {
/*Array*/
if(is_array($value)){
array_walk_recursive($value, "_CleanInputChars");
}
else{
/*Number,String*/
$_GET[$key] = _CleanInputChars($value);
}
}
/*END prevent Sql Injection*/
?>

Example for Mysqli
Mysli '#' mean mysql no execute query after '#'.
Form username input:
nouser" or 1=1#
nouser' or 1=1#

PHP warning session_start() - SOLVED

Description: PHP Warning:  session_start(): Cannot send session cache limiter - headers already sent
It's hard to check. So wast much time to debug.

On internet guide is session_start() is the top code+html : YES- this right
BUT: it's really hard debug on big site working.-> waste much time

The simple way is: 
1. Create 1 file testsession.php 
Add code
<?php  
session_start();
error_reporting(E_ALL ^ E_NOTICE);
?>
2. Upload to host
3. Run file testsession.php 
Check view error_log at root folder: No error_log, NO waring -> is GOOD status. This mean is OK
4. Check many parts source: this is the important step
Check above HTML
Check head
Check body
....
I found issue so easy.
Good luck

PHP prevent form resubmit - SOLVED

Detail: Form submit. Page reload -> form resubmit again. I did take 3 days to find on google and SOLVED. So thanks all.
Solution: catch session at Server

CODE:
Server PHP
if (isset($_POST['formid']) && isset($_SESSION['formid']) && $_POST["formid"] == $_SESSION["formid"])
{
$_SESSION["formid"] = '';
$isFirstSubmit = true;
}else{
$isFirstSubmit = false;
}
/*FormSession validate submit*/
$_SESSION["formid"] = md5(rand(0,10000000));

At Form Add 
<form>
<input type="hidden" name="formid" value="<?php echo htmlspecialchars($_SESSION["formid"]); ?>"/>
</form>

.htaccess directory index

Description: Use .htacccess file index priority index.php, index.html, index.asp...
Solution: .htaccess file
Add code:
DirectoryIndex index.php index.html

Joomla ERROR PAGE - Redirect to URL

File hiệu chỉnh: Hiệu chỉnh file templates/yourtemplate/error.php
Nguyên tắc hoạt động: khi jooml báo lỗi link sẽ chạy file error.php, lúc này file sẽ trỏ đến 1 bài viết trong joomla.
Mục đích: để giữ template hiển thị và style.
So sánh: có lợi hơn rất là là nhiều nếu redirect bằng html header <meta http-equiv="refresh" content="0; url=http://example.com/" />, lý do khi gặp file php là đang chạy ở server và redirect. Còn nếu chạy HTML Redirect thì lúc về đến client rồi mới redirect - lúc này người dùng sẽ thấy được trang trắng khoảng 1s.
Source:
<?php
$location=$this->baseurl.'/index.php?option=com_content&view=article&id=126&Itemid=718';
header("Location:".$location); /* Redirect browser */

/* Make sure that code below does not get executed when we redirect. */
exit;
?>

Xem version PHP và đường dẫn tuyệt đối trên host

Một vài trường hợp cần xem đường dẫn tuyệt đối trên host
Và xem version PHP
Download file sau: phpinfo.php
Link dự phòng:
https://drive.google.com/file/d/0B785Epf6q5XlVENZeFpJTUJIc0k/edit?usp=sharing

php get first image tag from string

<?php 
preg_match('/(<img[^>]+>)/i', $item['content'], $matches);
echo $matches[0]; 
?>

Thêm module JModuleHepler

Mô tả:
Bình thường xử lý Joomla tự động tạo <jdoc:include type="modules" name="left" style="xhtml" />, cấu trúc này không phải lúc nào cũng hoạt động đặc biệt là lúc cần thêm module vào 1 component.
Cách sử dụng:
Sử dụng đoạn code trong mã PHP của component, index.php, module  ... bất cứ ở đâu trong PHP
<?php
    //Module position VM-Category-Top
    jimport( 'joomla.application.module.helper' );
    $module = JModuleHelper::getModules( 'VM-Category-Top' );
    if(count($module)){?>
    <div id="ja-VM-Category-Top">
        <?php
        $attribs['style'] = 'xhtml';
        foreach ($module as $new_module){
            echo JModuleHelper::renderModule($new_module, $attribs);
        }?>      
        <div class="clr"></div>
    </div>
<?php } ?>