Situation:
//trollCommand.php
[...]
foreach ($trolltypes as $type) { //$type=={"Frost","RandomBroken","Forest"}
try {
$output->writeln($type);
$troll={"get".$type."TrollType"}();
$output->writeln("TEST 1");
$troll->__load();
$output->writeln("TEST 2");
} catch (EntityNotFoundException $e) {
$output->writeln("WARNING: TROLL ENTITY DOES NOT EXIST.");
continue;
}
$output->writeln("TROLLING");
do_something_with_troll($troll);
}
getFrostTrollType loads ok, getForestTrollType should be loaded ok too, but before that, it is a problem, getRandomBrokenTrollType() deliberately does not exist, and then I see message in console:
Frost
Test 1
Test 2
TROLLING
RandomBroken
Test 1
[Doctrine\ORM\EntityNotFoundException]
Entity was not found.
//[EXIT FROM SCRIPT]
troll#troll-machine ~/trollSandbox/ $ _
it should be: WARNING: TROLL ENTITY DOES NOT EXIST. and then continue; but it does not happen
How to check existing of a object's method?
if you're trying to catch any exception, you should use a backslash before "Exception".
E.g.:
try{
//do stuff here
}
catch(\Exception $e){
error_log($e->getMessage());
}
If you don't use a backslash, the exception won't be caught. This is due to how namespaces are used in PHP / Symfony.
the Exception thrown by Doctrine is called Doctrine\ORM\EntityNotFoundException and you are catching EntityNotFoundException.
Thats a difference, the namespace matters.
to debug this, catch Exception instead and observe the type of the actual exception. then replace it.
Exception Type is - \Doctrine\ORM\EntityNotFoundException
Don`t forget starting "\"
Example -
try {
$entityManager = $this->getEntityManager();
$entityManager->remove($entity);
$entityManager->flush(); // save to the database
} catch (\Doctrine\ORM\EntityNotFoundException $ex) {
echo "Exception Found - " . $ex->getMessage() . "<br/>";
}
Related
I'm trying to do a very basic exception try catch, but it doesn't catch.
$id =0;
try {
$question = $this->model->find($id); // will not find anything since $id = 0
$question->delete(); // throw an exception
return true;
} catch (\Exception $e) {
dd ('hello'); // should end up here, but no?!?!?
} catch (FatalThrowableError $f) {
echo ("fatal"); // or here... but no.
}
but the catch doesn't "catch". I get an Fatal error in the browser saying that delete was called on a null object. But that's exactly what I was trying to do: do a delete on a null object (id = 0 is not in the DB), to test the exception.
I have tried
use Symfony\Component\Debug\Exception;
use Symfony\Component\Debug\Exception\FatalThrowableError;
or simply
Exception;
FatalThrowableError;
Also, having the \Exception $e or Exception $e (with or without ) doesn't change anything.
Note that if I add a line like $foo = 4/0 I get into the Exception section (dd (hello)).
in .env APP_DEBUG=true, APP_LOG_LEVEL=debug
I'm on Laravel 5.5 using PHP 7.0.10 on windows 7.
http://php.net/manual/en/language.errors.php7.php
As the Error hierarchy does not inherit from Exception, code that uses
catch (Exception $e) { ... } blocks to handle uncaught exceptions in
PHP 5 will find that these Errors are not caught by these blocks.
Either a catch (Error $e) { ... } block or a set_exception_handler()
handler is required.
You can, additionally, catch (\Throwable $e) {} to account for both Error and Exception types.
When should I use Exception, InvalidArgumentException or UnexpectedValueException?
I don't know the real different between them as I always used Exception.
Different exceptions just give you more granularity and control over how you catch and handle exceptions.
Consider a class where you are doing many things - e.g. getting input data, validating input data and then saving it somewhere. You might decide that if the wrong or empty arguments are passed to the get() method, you might throw an InvalidArgumentException. When validating, if something is out of the ordinary or doesn't match up you could throw an UnexpectedValueException. If something totally unexpected happens you could throw a standard Exception.
This becomes useful when you are catching, as you can handle different types of exceptions in different ways. For example:
class Example
{
public function get($requiredVar = '')
{
if (empty($requiredVar)) {
throw new InvalidArgumentException('Required var is empty.');
}
$this->validate($requiredVar);
return $this->process($requiredVar);
}
public function validate($var = '')
{
if (strlen($var) !== 12) {
throw new UnexpectedValueException('Var should be 12 characters long.');
}
return true;
}
public function process($var)
{
// ... do something. Assuming it fails, an Exception is thrown
throw new Exception('Something unexpected happened');
}
}
In the above example class, when calling it you could catch multiple types of exceptions like so:
try {
$example = new Example;
$example->get('hello world');
} catch (InvalidArgumentException $e) {
var_dump('You forgot to pass a parameter! Exception: ' . $e->getMessage());
} catch (UnexpectedValueException $e) {
var_dump('The value you passed didn\'t match the schema... Exception: ' . $e->getMessage());
} catch (Exception $e) {
var_dump('Something went wrong... Message: ' . $e->getMessage());
}
In this case you get an UnexpectedValueException like this: string(92) "The value you passed didn't match the schema... Exception: Var should be 12 characters long.".
It should also be noted that these exception classes all end up extending from Exception anyway, so if you don't define special handlers for the InvalidArgumentException or others then they will be caught by Exception catchers anyway. So really, why not use them?
I have a problem where I want to catch all exception except descendants of my custom exception.
Maybe bad design, but here it is (Simplified and names changed, but the code is quite accurate):
function doStuff()
{
try {
// code
if (something) {
// manually throw an exception
throw StuffError("Something is bad.");
}
// a third-party code, can throw exceptions
LibraryClass::arcaneMagic();
} catch (Exception $e) {
throw new StuffError("Error occured while doing stuff: "
. $e->getMessage());
}
}
/** My custom exception */
class StuffError extends Exception
{
function __construct($msg) {
parent::__construct('StuffError: ' . $msg);
}
}
However, the issue here is that I don't want the try-catch to intercept the manually throws StuffError. Or, seamlessly rethrow it or something.
As it is now, I'd get:
StuffError: Error occured while doing stuff: StuffError: Something is bad.
I want just:
StuffError: Something is bad.
How would I do it?
You can have multiple catch clauses, and the first one that matches will be the one that runs. So you could have something like this:
try {
do_some_stuff();
}
catch (StuffError $e) {
throw $e;
}
catch (Exception $e) {
throw new StuffError(Error occurred while doing stuff: " . $e->getMessage());
}
But you might want to rethink wrapping stuff like this. It obscures the real cause of the error. For one thing, you lose the stack trace. But it also complicates error handling, since now someone can't differentiate exception types the way you're trying to do, short of trying to parse the exception message (which is rather an anti-pattern in itself).
I might be misinterpreting you, but I think this is what you're looking for:
...
} catch (Exception $e) {
if (get_class($e) == 'StuffError' || is_subclass_of($e, 'StuffError')) {
throw $e;
} else {
throw new StuffError("Error occured while doing stuff: "
. $e->getMessage());
}
}
...
Replace your catch statement with the code above. It checks to see if the exception is a StuffError or a child class of StuffError. I'm still very confused at why you would need to throw a StuffError exception after you catch, but maybe that's just some weirdness coming from translating/cleaning your code.
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();
}
I been searching for this and I just seem to run into the same articles, in this code:
try
{
//some code
}
catch(Exception $e){
throw $e;
}
Where does $e gets stored or how the webmaster see it? Should I look for a special function?
An Exception object (in this case, $e) thrown from inside a catch{} block will be caught by the next highest try{} catch{} block.
Here's a silly example:
try {
try {
throw new Exception("This is thrown from the inner exception handler.");
}catch(Exception $e) {
throw $e;
}
}catch(Exception $e) {
die("I'm the outer exception handler (" . $e->getMessage() . ")<br />");
}
The output of the above is
I'm the outer exception handler (This is thrown from the inner exception handler.)
One nice thing is that Exception implements __toString() and outputs a call stack trace.
So sometimes in low-level Exceptions that I know I'm gonna want to see how I got to, in the catch() I simply do
error_log($e);
$e is an instance of Exception or any other class that extended from Exception. Those objects have some specific attributes and methods in common (inherited from the Exception class) you can use. See the chapter about exceptions and the Exception member list for more details.
I'm assuming your using some sort of third party code/library with this code in it that is throwing the exception into your code. You simply have to be ready for an exception to be thrown to catch it, then you can log it/display it however you want.
try {
$Library->procedure();
catch(Exception $e) {
echo $e->getMessage(); //would echo the exception message.
}
For more information read the PHP manual's entry on Exceptions.
The lines:
catch(Exception $e){
throw $e;
}
Don\t make sense. When you catch an Exception you're suppose to do something with the exception like:
catch(Exception $e){
error_log($e->getMessage());
die('An error has occurred');
}
But in your case the Exception is thrown directly to an outer try-block which would already happen.
If you change your code to:
//some code
Would create the exact same behaviour.