I'm doing the first test on php5. More specifically I'm trying to work with namespaces but it seems that php is not resolving the namespace. Here the test I've done:
file 1: test.php
<?
namespace \first_test;
class Test {
function test_function(){
print "works";
}
}
?>
file 2: use_namespace.php
<?
use \first_test;
$a=new \first_test\Test();
$a->test_function();
?>
I get a fatal error:
Fatal error: Class 'first_test\Test' not found in
here_the_path_where use_namespace.php is.
Any help appreciated.
P.S. Both files are on the same directory, php 5.3.9 on windows.
You don't need the \ when declaring a namespace, you only need it when calling functions from it.
<?php
namespace first_test;
// ...
?>
Also, in your 2nd file, you need to include test.php, otherwise it doesn't know what first_test is.
In the 3rd-party library they most likely use autoloader, which automaticly does all the required includes. So if you dont want to manually write include, add your own autoloader
http://php.net/manual/en/language.oop5.autoload.php
It is a general aproach that you entry point contains autoloader, so all included files will use it automaticly. Description of coding standart for this can be found at https://www.php-fig.org/psr/psr-4/
Related
I am just getting my feet wet with PHP autoloading. I actually think I got the basics down, but somehow it still won't work.
I got the following directory structure:
myLib
-bootstrap.php
-sven
-project
project.php
bootstrap.php is the file that will be included to use the lib. In this file, I simply have the following code:
spl_autoload_extensions('.php');
spl_autoload_register();
$var = new \sven\project\project();
$var->init();
And in project.php:
namespace sven\project;
class project {
public function init() {
echo 'It works!';
}
}
The way the autoloader is used, to my understanding, the core PHP autoloader should translate the namespace into directories and then look for a php containing the class.
Instead of displaying 'It works!', a fatal error is thrown. Unfortunately, I can't exactly tell what that error is because the CMS only informs me that there was a fatal error.
But with such a simple structure, I am sure the error is pretty basic and easy to find for someone who knows how it works.
Where am I going wrong with this example – did I correctly describe how the autoloader should work in this setup or is there a misunderstanding?
EDIT: Finally got the error log running:
Fatal error: Class undefined: sven\\project\\project\\project\\project in /xxx/bootstrap.php on line 36
That obviously looks wrong, but how to change that? Why are there two backslashes?
spl_autoload_extensions('.php');
spl_autoload_register();
This code works only with PHP 5.3 and above.
Sven,
I just answered another question about spl_autoload, try my example click here
I hope it helps!
PS:
Also don't just autoload all .php files on your path , that can be dangerous !
I just wanna use a namespace in another file, to use the class in it, but im too retarded to do this...
first file:
namespace fun;
use fun\kjr\trouble;
$trouble = new trouble('http://someURL');
second file:
namespace fun\kjr;
class trouble { ... }
This is the error i get:
Error: Fatal error: Class 'fun\kjr\trouble' not found in D:\wamp\www\fun\index.php on line 8
Where did I declare a wrong namespace? Oo
Greetings
I had to include my class aswell.
use namespace
only makes the class available in the actual context.
It does NOT include it, so you can cause it.
use
include_once('your.file')
to do that!
Thanks #Michael Berkowski for helping.
The problem (from what I can see) is you haven't specified an autoloader (e.g. with spl_autoload_register()) or haven't included the file in your code. The use statement will only find a class for you if you have an autoloader in place, otherwise you must include your code ahead of time with include/include_once or require/require once.
I would start with making an autoloader and registering it and then it may be wise to map your namespaces to directory structure as specified by PSR-0.
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 started to use the PHP __autoload function and now I'm getting those weird Fatal error: Cannot redeclare class xxx errors.
It's weird since these errors occur on classes I don't even load with the autoload function. And I also use require_once to include the files.
I'm really puzzled about this. Anyone knows anything about this kind of errors when using autoload?
require_once/include_once only looks at the file name when they're trying to include a file, not a class name. So you can have class Foo in both Foo.php and B.php, and then you'll get that error.
I'm not sure how __autoload would cause you any problems, unless __autoload requires Foo.php because it needs class Foo, and you require B.php manually which redefines class Foo.
By the way, use spl_autoload_register instead of __autoload.
i had same situation .. all i changed was and its working for me
include('xxx.php');
to
require_once('xxx.php');
I am not pretend on the best answer. Just my thoughts.
__autoload() is deprecated in PHP 7.2 and will be possiblly deleted.
I found this way to upload/include files
//initialize a function which will upload files
function upload(){//you can call the function as you like
//your path to files goes here
}
spl_autoload_register('upload')//specify the function, where you include your files(in this case it's upload function
I've had this before, not sure what caused it though. Make sure you're using require_once/include_once rather than the normal versions for starters. I think the problem was related to using class_exists without telling it to skip autoloading (class_exists($name, false)) - are you doing this?
I found the problem. Apparently when it wanted to include Bank class, it took the "bank.php" file from the current directory ^^. Which is just the bank page, it should have include "src/model/Bank.php". I removed the current directory from the search list and it has been fixed.
So always make sure the autoload function is including the correct files. Good practice is too name your files more straightforward like class.Bank.php or class.User.php instead of Bank.php or User.php.
Thanks for your help and quick response anyway!
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.