I'm having trouble catching an exception in PHP
Here's my code.
try {
require $this->get_file_name($action);
}
catch (Exception $e) {
//do something//
}
and the method being called
private function get_file_name($action) {
$file = '../private/actions/actions_'.$this->group.'.php';
if (file_exists($file) === false) {
throw new Exception('The file for this '.$action.' was not found.');
}
else {
return $file;
}
}
Resulting in:
Fatal error: Uncaught exception 'Exception' with message $action was not found.'
Exception: The file for this $action was not found.
However If I put a try-catch block inside of the function and call the function, I'm able to catch the exception no problem.
What am I doing wrong?
If you are catching the Exception inside a namespace, make sure that you fall back to the global namespace:
...
}(catch \Exception $e) {
...
}...
You can also have a look at the following resources:
Why isn't my Exception being caught by catch?
http://php.net/manual/en/language.exceptions.php, top note by user zmunoz
I can't see all of the class body but If You want to use method out of the class it should be Public not Private.
Try to check if file You trying to get exists:
var_dump($file = '../private/actions/actions_'.$this->group.'.php');
IMO there is no file in this path
Related
Here is my code:
try {
if ( condition 1 ) {
throw;
} else {
// do something
}
// some code here
if ( condition 2 ){
throw;
}
} catch (Exception $e) {
echo "something is wrong";
}
As you see, my catch block has its own error message, And that message is a constant. So really I don't need to pass a message when I use throw like this:
throw new Exception('error message');
Well can I use throw without anything? I just need to jump into catch block.
Honestly writing an useless error message is annoying for me.
As you know my current code has a syntax error: (it referring to throw;)
Parse error: syntax error, unexpected ';' in {path}
message parameter is optional in the Exception constructor. So if you don't have/want to put - just don't:
throw new Exception;
But you still must throw an instance of the Exception class (or a class that extends it), since it is a part of the php language syntax.
If you want all your exceptions to have the same message, you can extend it and define the message in your class:
class AmbiguousException extends Exception {
public function __construct($message = 'Something is wrong.', $code = 0, Exception $previous = null) {
parent::__construct($message, $code, $previous);
}
}
Then:
throw new AmbiguousException();
You can use the below throw everytime you need.
throw new Exception();
and catch will remain same as your code.
As stated in the PHP manual:
The thrown object must be an instance of the Exception class or a subclass of Exception. Trying to throw an object that is not will result in a PHP Fatal Error.
You can throw an exception without any message:
throw new Exception();
Perhaps something to help you from duplicating the same exception is as follows:
$e = new Exception('something is wrong');
try {
throw $e;
} catch (Exception $ex) {
echo $ex->getMessage();
}
You can create an instance with default message and then throw that instance.
$Exception = new Exception("some error message!");
try {
throw $Exception;
} catch (Exception $ex) {
var_dump($ex);
}
You cannot use the throw keyword on its own. However, you can use throw new Exception(); without specify the $message parameter, because it'll just fallback to the default message. Check out the Exceptions section in the PHP manual: http://php.net/manual/en/language.exceptions.extending.php
I'm trying to catch a Laravel exception inside my library.
namespace Marsvin\Output\JoomlaZoo;
class Compiler
{
protected function compileItem($itemId, $item)
{
$boom = explode('_', $itemId);
$boom[0][0] = strtoupper($boom[0][0]);
$className = __NAMESPACE__."\\Compiler\\".$boom[0];
try {
$class = new $className(); // <-- This is line 38
} catch(\Symfony\Component\Debug\Exception\FatalErrorException $e) {
throw new \Exception('I\'m not being thrown!');
}
}
}
This it the exception I'm getting:
file: "C:\MAMP\htdocs\name\app\libraries\WebName\Output\JoomlaZoo\Compiler.php"
line: 38
message: "Class 'Marsvin\Output\JoomlaZoo\Compiler\Deas' not found"
type: "Symfony\Component\Debug\Exception\FatalErrorException"
The name of the class is voluntarily wrong.
Edit 1:
I noticed that if I throw an exception inside the try statement I can catch the exception:
try {
throw new \Exception('I\'d like to be thrown!');
} catch(\Exception $e) {
throw new \Exception('I\'m overriding the previous exception!'); // This is being thrown
}
The problem is that you're trying to catch a FatalErrorException in your class, but Laravel won't let a fatal error get back there; it terminates immediately. If your were trying to catch a different kind of exception, your code would work just fine.
You can catch and handle fatal errors with an App::fatal method in app/start/global.php, but that won't help you deal with the exception from within your library, or to handle it with any specificity. A better option would be to trigger a "catchable" exception (something from Illuminate, for instance), or to throw a custom one based on the condition that you are trying to check.
In your case, if your goal is to deal with undefined classes, here's what I would suggest:
try {
$className = 'BadClass';
if (!class_exists($className)) {
throw new \Exception('The class '.$className.' does not exist.');
}
// everything was A-OK...
$class = new $className();
} catch( Exception $e) {
// handle the error, and/or throw different exception
throw new \Exception($e->getMessage());
}
I am trying to use exception handling in case a file does not exists. For example when I run the model method and pass a string usr (which I know there is no file with that name) . It gives me the following error message
Fatal error: Uncaught exception 'Exception' with message 'Usr.php was not found' in /app/core/controller.php on line 14
I can't figure out whats wrong here. Can someone please help me figure this out?
Below is my code. Thanks alot!
class Controllers{
public function model($model){
if(!file_exists("../app/models/".$model.".php")) {
throw new exception("{$model}.php was not found");
}
try {
require ("../app/models/".$model.".php");
} catch(Exception $e) {
echo $e->getMessage();
}
return new $model();
}
}
You can't throw an exception without catching it; this automatically causes the PHP script to crash. So, you need to surround your entire function in the try-catch block, or the "model not found" exception will be uncaught. Your code should be something like this:
<?php
class Controllers {
public function model($model){
try {
if (!file_exists("../app/models/".$model.".php")) {
throw new Exception("{$model}.php was not found");
}
require ("../app/models/".$model.".php");
} catch(Exception $e) {
echo $e->getMessage();
}
return new $model();
}
}
Never mind guys! I found out I needed to use the try/catch blocks in the file where my method is being invoked
Example..
class Home extends Controllers{
public function index($name = ""){
try{
$user = $this->model('Usr');
}catch (Exception $e){
echo $e->getMessage();
}
//var_dump($user);
}
How do i catch (custom)exceptions (with custom exception handler) that i have thrown in custom shutdown function ? I am not using any framework.
Example:
register_shutdown_function( 'shutdownFunction');
set_exception_handler( 'exceptionHandler');
function exceptionHandler(Exception $exception)
{
// handle and log exception for later debugging...
}
function shutdownFunction()
{
// something is not going right...
if (someVariable != someValue)
throw new RuntimeException('blah...'); // WILL NOT be caught by exception handler
}
// somewhere else in the code...
throw new Exception('something...'); // WILL be caught by exception handler (but not in shutdown function)
The script is using exceptions to communicate that it encountered an error during execution ie. unexpected variable passed to function, database failed to insert row etc...
You simply cannot do this in php.
The register_shutdown_function callback is the last thing that happens in your PHP application. Trying to throw an exception in there will not do anything but invoke a standard php handler. There isn't much to be found on the web regarding these inner workings.
However, I created my own solution for directing it to a single function.
set_exception_handler and register_shutdown_functionare very different functions:
set_exception_handler receives a single argument Exception
register_shutdown_function receives no arguments by default
I've made it so that the set_exception_handler (which receives $exception as argument) sets a property which I can use in the register_shutdown_function.
$lastException = null;
set_exception_handler(function ($e) use (&$lastException) {
$lastException = $e;
});
register_shutdown_function(function() use(&$lastException) {
if($error = error_get_last()) {
$lastException = new \ErrorException($error['message'], $error['type'], 1, $error['file'], $error['line']);
}
if($lastException) {
if (APPLICATION_ENV === 'production') {
Sentry\captureException($lastException);
} else {
var_dump($lastException);
}
}
});
I have no clue if this is a good way to solve the issue, but it allowed me to catch require unexisting_phpfile1389.php errors (Fatal) and regular throw \Exception()s in the same function.
Trying to throw an exception inside the shutdown handler will result in the following exception (how ironic):
( ! ) Fatal error: Uncaught Error: Can only throw objects in
C:...\index.php on line 34
( ! ) Error: Can only throw objects in
C:...\index.php on line 34
You can just wrap the body of your shutdownFunction with
function shutdownFunction()
try {
...
} catch (\Exception $e) {
// do something
}
}
and you will catch all exceptions becase Exception is the base class for all of them
It's quite simple:
function exception_handler (Exception $e) {
if ($e instanceof DBException)
error_handler (['query' => $e->getQuery ()]); // Your actions with your custom Exception object
}
function error_handler ($error) {
if (isset ($error['query']))
echo $error['query'];
else
// Another errors
}
set_error_handler ('error_handler', E_ALL);
set_exception_handler ('exception_handler');
I am trying to understand what the best approach would be to handle Exceptions in the following scenario:
I have a class employee:
class employee extends person {
private $salary;
private $baseSalary = 6.5;
function __construct($f, $m, $l, $a,$fsalary=0){
if(!is_numeric($fsalary)){
throw new Exception("Age supplied is not a number", 114);
}
parent::__construct($f, $m, $l, $a);
$this->salary=$fsalary;
}
function GetDetails(){
return parent::GetName().
"<br/>".
$this->salary;
}
function __toString(){
return $this->GetDetails();
}
}
And using this:
try{
if(!$f = new employee("Sarah", "Sebastian", "Pira", "abc")){
throw new Exception();
}
else {
echo $f;
}
}
catch (Exception $e){
echo "<br/>";
echo var_dump($e);
}
Now I would think it would be a good idea to throw an exception in the class and then use just one catch block in all the scripts that would be using an employee object - But this doesn't seem to work - I need to have a try catch block within the class - Is this the correct way of looking at this?
Thanks
I think what you're saying is that you want to do something like this:
try {
class Employee extends Person {
// ...blah blah...
}
}
catch(Exception $e) {
// handle exception
}
...and then be able to insantiate it in other classes, without explicitly catching any exceptions:
// try { << this would be removed
$employee = new Employee();
// }
// catch(Exception $e) {
// (a whole bunch of code to handle the exception here)
// }
You can't do that, because then the try/catch block in the class will only catch any exceptions that occur when defining the class. They won't be caught when you try to instantiate it because your new Employee line is outside the try/catch block.
So really, your problem is that you want to be able to re-use a try/catch block in multiple places without re-writing the code. In that case, your best solution is to move the contents of the catch block out to a separate function that you can call as necessary. Define the function in the Employee class file and call it like this:
try {
$employee = new Employee();
$employee->doSomeStuff();
$employee->doMoreStuffThatCouldThrowExceptions();
}
catch(Exception $e) {
handle_employee_exception($e);
}
It doesn't get rid of the try/catch block in every file, but it does mean that you don't have to duplicate the implementation of the exception-handling all the time. And don't define handle_employee_exception as an instance method of the class, do it as a separate function, otherwise it will cause a fatal error if the exception is thrown in the constructor because the variable won't exist.
You should read more about Exceptions in PHP.
You can handle exceptions within the methods of the class, sure. But you should rethink how you want to do this and... why.
Good practice is also creating own exception class, so you are able to distinguish exceptions thrown by your module / class from the exceptions thrown by something else. It looks like that (see more):
class EmployeeModule_Exception extends Exception {}
and when it comes to throwing exception:
// the second parameter below is error code
throw new EmployeeModule_Exception('some message', 123);
Catching is similar, only the below example will catch only your module's exceptions:
try {
// some code here
} catch (EmployeeModule_Exception $e) {
// display information about exception caught
echo 'Error message: ' . $e->getMessage() . '<br />';
echo 'Error code: ' . $e->getCode();
}