This is confusing because I've checked other answers and applied them, but I still keep getting this fatal error.
I'm using phpmailer in wordpress and have this code:
if (!class_exists('PHPMailer')) {
require_once(ABSPATH . 'wp-content/uploads/phpmailer/_lib/class.phpmailer.php');
}
The page doesn't load, however, and I get the error:
PHP Fatal error: Cannot redeclare class PHPMailer in
(I also tried class_exists('PHPMailer', false)) but that also produced the same error.)
As far as I can see, by checking the class does not exist and then using require_once I shouldn't have this problem.
But I do...
Any help appreciated.
PHPMailer instance already working in wordpress. You do not need to include library again. Check this link for your reference
https://codex.wordpress.org/Plugin_API/Action_Reference/phpmailer_init
I think this is probably a simpler issue than namespaces: class_exists takes a second autoload parameter that defaults to true, and it means that it will automatically attempt to load the class if it's not already loaded and it can find it in your include_path. The net result is that by leaving that param at its default value, you're effectively loading it twice, hence the redeclaration error. Try this instead:
if (!class_exists('PHPMailer', false)) {
require_once(ABSPATH . 'wp-content/uploads/phpmailer/_lib/class.phpmailer.php');
}
In other news: use composer. It manages all your class loading for you. It's worth it for even trivial scripts.
Related
I'm building a 'core' for php. That 'core' is loaded before to load an application, for example Wordpress. Now, for example the 'phpmailerException' class is a part of Wordpress, but it is a part of the 'core' too. How can I ignore the fatal error: 'cannot redeclare...'. ¿There is way using php.ini or a special function?
Thanks
You should use a check with class_exists , and then declare your classes.
I don't know what do you mean by core.
I assume that's a php file your created.
If you load (by include/require) it at the beginning, then you can't prevent the cannot redeclare error. There is no way to skip such error by settings.
If the core is something like a plugin, then you could use class_exists, function_exists to check whether a class or a function is already declared.
It is also worth checking if WordPress is using include_once/require_once instead of include/require. If WordPress is using include_once/require_once you have to make sure you are using include_once/require_once as well. That way, you can be sure your classes will be included once
I seem to have some misconceptions on how autoloading works in PHP still, one I simply cannot explain.
I have a class called glue which has a spl_autoload_register within it's main function, here called run like so:
class glue{
public static function run(){
spl_autoload_register(array('glue','autoload'));
}
}
The autoload function works by loading via the PSR-0 standard and works from absolute paths. This is all tested as working etc. Note that glue is not namespaced.
The autoload function covers a namespace called glue. Within this namespace I have a error handler called \glue\ErrorHandler.
When I trigger an error the glue class will autoload \glue\ErrorHandler by PSR-0 notation from the root directory as defined by a stored ROOT constant. This has been tested as working as well in classes such as \glue\User and \glue\Session.
So now for the problem. I cause a Call-time pass-by-reference has been deprecated error within \glue\Validation and it doesn't seem to run my autoload function.
I can see how it is going into my autoload function for everything but when I call this error in that class it just seems to skip my autoloader and bail out saying it can't find my error handler class.
Normally I would say it is something with my programming but I have tried everything. I cannot explain how, for this one error. What compounds my confusion further is that if I cause a:
syntax error, unexpected T_ISSET in /media/server_ws/xxxxxxx/glue/Validation.php on line 47
Error it works. It seems to be for that one error it just will not autoload my error handler.
I thought this might be because my spl_autoload_register is not being binded to that namespace (since the error handler that works is actually called from within glue) and some how, maybe, it is randomly working. So from \glue\Validation I called a class I have never looked at: \glue\util\Crypt but that works and goes into the autoloader correctly.
When I call this error: Call-time pass-by-reference has been deprecated from within glue class it works perfectly.
Can anyone shed some light on this?
Edit
As requested here is a brievated version of Validation.php:
namespace glue;
use glue,
\glue\Exception,
\glue\Collection;
class Validation extends \glue\Component{
private function validateRule($rule){
// This is the line, notice the pass by reference down there?
$valid = $validator($field,$field_value,$params,&$this->model) && $valid;
}
}
The Call-time pass-by-reference has been deprecated error is thrown during script compilation, and auto-loading is disabled during compilation. It's disabled because the compiler cannot start compiling multiple scripts at the same time (i.e. it is not re-entrant), and auto-loading may load some script, which may require compiling it.
Source: https://github.com/php/php-src/blob/76ad52ccc501c02aeb068d2eb4f119ef6f0c2b6a/Zend/zend_execute_API.c#L1058
Does anyone know what can cause this problem?
PHP Fatal error: Cannot redeclare class
You have a class of the same name declared more than once. Maybe via multiple includes. When including other files you need to use something like
include_once "something.php";
to prevent multiple inclusions. It's very easy for this to happen, though not always obvious, since you could have a long chain of files being included by one another.
It means you've already created a class.
For instance:
class Foo {}
// some code here
class Foo {}
That second Foo would throw the error.
That happens when you declare a class more than once in a page.
You can fix it by either wrapping that class with an if statement (like below), or you can put it into a separate file and use require_once(), instead of include().
if (!class_exists('TestClass')) {
// Put class TestClass here
}
Use include_once(); - with this, your codes will be included only one time.
This will happen if we use any of the in built classes in the php library. I used the class name as Directory and I got the same error. If you get error first make sure that the class name you use is not one of the in built classes.
This error might also occur if you define the __construct method more than once.
Sometimes that happens due to some bugs in PHP's FastCGI.
Try to restart it. At Ubuntu it's:
service php-fastcgi restart
I had the same problem while using autoload like follows:
<?php
function __autoload($class_name)
{
include $class_name . '.php';
}
__autoload("MyClass1");
$obj = new MyClass1();
?>
and in other class there was:
namespace testClassNamespace;
class MyClass1
{
function __construct()
{
echo "MyClass1 constructor";
}
}
The sollution is to keep namespace compatibility, in my example namespace testClassNamespace; in both files.
Just adding;
This error can also occur if you by mistake put a function inside another function.
PHP 5.3 (an I think older versions too) seems to have problem with same name in different cases. So I had this problem when a had the class Login and the interface it implements LogIn. After I renamed LogIn to Log_In the problem got solved.
Just do one thing whenever you include or require filename namely class.login.php. You can include it this way:
include_once class.login.php or
require_once class.login.php
This way it never throws an error.
This function will print a stack telling you where it was called from:
function PrintTrace() {
$trace = debug_backtrace();
echo '<pre>';
$sb = array();
foreach($trace as $item) {
if(isset($item['file'])) {
$sb[] = htmlspecialchars("$item[file]:$item[line]");
} else {
$sb[] = htmlspecialchars("$item[class]:$item[function]");
}
}
echo implode("\n",$sb);
echo '</pre>';
}
Call this function at the top of the file that includes your class.
Sometimes it will only print once, even though your class is being included two or more times. This is because PHP actually parses all the top-level classes in a file before executing any code and throws the fatal error immediately. To remedy this, wrap your class declaration in if(true) { ... }, which will move your class down a level in scope. Then you should get your two traces before PHP fatal errors.
This should help you find where you class is being included from multiple times in a complex project.
Did You use Zend Framework? I have the same problem too.
I solved it by commenting out this the following line in config/application.ini:
;includePaths.library = APPLICATION_PATH "/../library"
I hope this will help you.
Another possible culprit is source control and unresolved conflicts. SVN may cause the same class to appear twice in the conflicted code file; two alternative versions of it ("mine" and "theirs").
I have encountered that same problem:
newer php version doesn't deal the same with multiple incluse of the same file (as a library), so now I have to change all my include by some include_once.
Or this tricks could help, if you d'ont have too much class in your library...
if( class_exists('TestClass') != true )
{
//your definition of TestClass
}
I had the same problem "PHP Fatal error: Cannot redeclare class XYZ.php".
I have two directories like controller and model and I uploaded by mistakenly XYZ.php in both directories.(so file with the same name cause the issue).
First solution:
Find in your whole project and make sure you have only one class XYZ.php.
Second solution:
Add a namespace in your class so you can use the same class name.
It actually means that class is already declared in the page and you are trying to recreate it.
A simple technique is as follow.
I solved the issue with the following. Hope this will help you a bit.
if(!class_exists("testClassIfExist"))
{
require_once("testClassIfExist.php");
}
i have encountered that same problem. found out the case was the class name. i dealt with it by changing the name. hence resolving the problem.
You must use require_once() function.
I have trying to solve the error : Fatal error: Cannot redeclare class
I have been looking everywhere and I can't find where the class was instantiated.
Is there anyway I can print debug info about the existing instance of that class.
Chances are you are importing the file that declares the class more than once. This can be symptomatic of includes/requires getting out of control so you may need to simply your structure.
One alternative approach is to use autoload to load classes to avoid this kind of problem. Another is to only use include_once or require_once. I generally prefer to use require with a simple structure.
Yes, stupid php doesn't tell you where the class was declared. Try the following (immediately before fatal error line)
$r = new ReflectionClass("YourClassName"); echo $r->getStartLine();
You can find out, where an object was instantiated by using var_dump(debug_backtrace()); and looking at the call stack.
Does anyone know what can cause this problem?
PHP Fatal error: Cannot redeclare class
You have a class of the same name declared more than once. Maybe via multiple includes. When including other files you need to use something like
include_once "something.php";
to prevent multiple inclusions. It's very easy for this to happen, though not always obvious, since you could have a long chain of files being included by one another.
It means you've already created a class.
For instance:
class Foo {}
// some code here
class Foo {}
That second Foo would throw the error.
That happens when you declare a class more than once in a page.
You can fix it by either wrapping that class with an if statement (like below), or you can put it into a separate file and use require_once(), instead of include().
if (!class_exists('TestClass')) {
// Put class TestClass here
}
Use include_once(); - with this, your codes will be included only one time.
This will happen if we use any of the in built classes in the php library. I used the class name as Directory and I got the same error. If you get error first make sure that the class name you use is not one of the in built classes.
This error might also occur if you define the __construct method more than once.
Sometimes that happens due to some bugs in PHP's FastCGI.
Try to restart it. At Ubuntu it's:
service php-fastcgi restart
I had the same problem while using autoload like follows:
<?php
function __autoload($class_name)
{
include $class_name . '.php';
}
__autoload("MyClass1");
$obj = new MyClass1();
?>
and in other class there was:
namespace testClassNamespace;
class MyClass1
{
function __construct()
{
echo "MyClass1 constructor";
}
}
The sollution is to keep namespace compatibility, in my example namespace testClassNamespace; in both files.
Just adding;
This error can also occur if you by mistake put a function inside another function.
PHP 5.3 (an I think older versions too) seems to have problem with same name in different cases. So I had this problem when a had the class Login and the interface it implements LogIn. After I renamed LogIn to Log_In the problem got solved.
Just do one thing whenever you include or require filename namely class.login.php. You can include it this way:
include_once class.login.php or
require_once class.login.php
This way it never throws an error.
This function will print a stack telling you where it was called from:
function PrintTrace() {
$trace = debug_backtrace();
echo '<pre>';
$sb = array();
foreach($trace as $item) {
if(isset($item['file'])) {
$sb[] = htmlspecialchars("$item[file]:$item[line]");
} else {
$sb[] = htmlspecialchars("$item[class]:$item[function]");
}
}
echo implode("\n",$sb);
echo '</pre>';
}
Call this function at the top of the file that includes your class.
Sometimes it will only print once, even though your class is being included two or more times. This is because PHP actually parses all the top-level classes in a file before executing any code and throws the fatal error immediately. To remedy this, wrap your class declaration in if(true) { ... }, which will move your class down a level in scope. Then you should get your two traces before PHP fatal errors.
This should help you find where you class is being included from multiple times in a complex project.
Did You use Zend Framework? I have the same problem too.
I solved it by commenting out this the following line in config/application.ini:
;includePaths.library = APPLICATION_PATH "/../library"
I hope this will help you.
Another possible culprit is source control and unresolved conflicts. SVN may cause the same class to appear twice in the conflicted code file; two alternative versions of it ("mine" and "theirs").
I have encountered that same problem:
newer php version doesn't deal the same with multiple incluse of the same file (as a library), so now I have to change all my include by some include_once.
Or this tricks could help, if you d'ont have too much class in your library...
if( class_exists('TestClass') != true )
{
//your definition of TestClass
}
I had the same problem "PHP Fatal error: Cannot redeclare class XYZ.php".
I have two directories like controller and model and I uploaded by mistakenly XYZ.php in both directories.(so file with the same name cause the issue).
First solution:
Find in your whole project and make sure you have only one class XYZ.php.
Second solution:
Add a namespace in your class so you can use the same class name.
It actually means that class is already declared in the page and you are trying to recreate it.
A simple technique is as follow.
I solved the issue with the following. Hope this will help you a bit.
if(!class_exists("testClassIfExist"))
{
require_once("testClassIfExist.php");
}
i have encountered that same problem. found out the case was the class name. i dealt with it by changing the name. hence resolving the problem.
You must use require_once() function.