PHP CodeIgniter Errors not stopping execution of Try Blocks - php

I'm using CodeIgniter and am trying to execute code in a try/catch block with the idea that errors will stop execution of the code after the error until the catch block is reached, as you would normally think it would work.
However on encountering PHP Errors, the code is continuing. This is causing a database transaction complete command to execute which is .... very bad if there's an error and all of the instructions weren't carried out properly. For example, I have this code which is executed in an ajax request:
// start transaction
$this->db->trans_start();
try {
$this->M_debug->fblog("firstName=" . $triggerOpts->{'firstXXXName'});
$data = array("test_col" => 123);
$this->db->where("id", 4);
$this->db->update("my_table", $data);
// if got this far, process is ok
$status = "process_ok";
// complete transaction
$this->db->trans_complete();
} catch (Exception $ex) {
// output the error
$this->M_debug->logError($ex);
}
In this code, I'm trying to execute a database update as part of a transaction.
My call to $this->M_debug->fblog() is designed to just log a variable to PHP Console, and I've deliberately tried to log a variable that does not exist.
This causes a PHP error, which I guess is a fatal error, and the desired result is that the code after the log commands fails, and the transaction does not complete. However after this error, despite reporting the PHP error in Chrome console, the code keeps right on executing, the database is updated and the transaction is completed. Would appreciate any help in how i could stop this from happening.
Thanks very much, G
EDIT --
As requested heres fblog(), it's simply a Chrome console log request of a variable
public function fblog( $var ) {
ChromePhp::log( $var );
}

Assuming you're using PHP 7.0 or higher, you can catch PHP errors as well as exceptions, however you need to catch Error or the parent Throwable type rather than Exception.
try {
...
} catch (Throwable $ex) {
//this will catch anything, including Errors and Exceptions
}
or catch them separately if you want to do something different for each of them...
try {
...
} catch (Exception $ex) {
//this will catch Exceptions but not errors.
} catch (Error $ex) {
//this will Errors only
}
Note that if you're still only PHP 5.x, the above won't work; you can't catch PHP errors in older PHP versions.

Related

Try/Catch breaks PHP script

SOLUTION: I've been working on the iOS side of it at the same time and must have got the languages switched up. Instead of the $, I put *.
I am trying to get a try{} catch{} working in PHP. My code works when I remove the try{} catch{}. Once I put it back in, it breaks my script. I even tried making it empty in both the try{} catch{}, but it still crashes my script.
try {
}
catch (Exception *e) {
}
Is there a reason the try{} catch{} would cause the script to crash? When I run it in my browser it just shows a white screen.
I even went and made another empty PHP file and put this code in without the if statement. And still, it doesn't work. The page is still white. I had it echo in the try.
Your catch declaration is incorrect.
catch (Exception *e) {
Should be.
catch (Exception $e) {
The inaccurate code would cause a parse error, thus preventing the script from running at all, and producing a white screen.
Maybe possibilities catch is not getting the object values. You should use it as:
try
{
some statement....
}
catch(Exception e)
{
some statement...
}

how to change Internal server error code in an php application?

In my PHP aplication,I want that whenever -Internal Server or 500 error occurs,I want the error code to be changed from 500 to 302.I mean error code 302.
Try to use http_response_code.Also, take a look on related question How to return an HTTP 500 code on any error, no matter what.
i would not recommend you do that.
Instead wrap your code that is generating this error within a Try & Catch statement and try to handle exception there.
try {
// your code here
} catch (Exception $e) {
echo $e->getMessage();
}

How to prevent a try-catch error from stopping execution

I've read this thread: php: catch exception and continue execution, is it possible?
Every answer suggests that a try catch will continue executing the script. Here is an example where it doesn't:
try{ $load = #sys_getloadavg(); }
catch (Exception $e){ echo 'Couldn\'t find load average.<br>'; return false; }
I'm running it on xampp on windows, which could be why it errors (it gives a Call to undefined function sys_getloadavg() error when the # is removed), but that isn't the issue in question. It could be any function that doesn't exist, isn't supported or fails - I can not get the script to continue executing.
Another example is if there is a syntax error in the try, say I'm including an external file and parsing it as an array. This also produces an error and stops executing.
Is there any brute force way to continue the script running, regardless of what fails in the try?
Unlike other languages, there's a difference in PHP between exceptions and errors. This would be like a compile error in other languages. that require declaration files. You can't catch or ignore Fatal errors like a function not exisiting. You can test for existence before using though:
if( function_exists('sys_getloadavg') {
try{ $load = #sys_getloadavg(); }
catch (Exception $e){ echo 'Couldn\'t find load average.<br>'; return false; }
}

Loggin' try-catch transactions

My code is
try{
$this->_db->beginTransaction();
$stmt = $this->_db->prepare("...");
$stmt->execute(array($var1, $var2));
...
} catch (Exception $e) {
$stmt->rollBack();
}
I want to log this action to my log file with a function
as you see this one meant to save errors in transaction. Another one should also save the succeeded attempts. BUT if I put them inside of try{} and catch{} they not working for some reason. outside it does work good but I'm not sure what exactly should I check here for true/false to see the result outside of try/catch.
Thanks for your answers. I'm just learning so my questions might be stupid. Sorry for this. =)
Update.
What I've tried to do is:
try{...
} catch (Exception $e) {
$stmt->rollBack();
file_put_contents(LOG_CONST, date("r")." UderID: ".$id." Error: ".$e->getMessage()."\n", FILE_APPEND);
}
And it didn't put anything.
Update 2
Not sure if I have to add a new details here or I should answer to myself... Anyway. Right now I'm trying this code
try{
$this->_db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$this->_db->beginTransaction();
$stmt = $this->_db->prepare
..................
$stmt->execute(array($var));
file_put_contents(DATACHANGE_LOG, date("r")." ".n307." UderID: ".$id."\n", FILE_APPEND);
$this->_db->commit();
} catch (Exception $e) {
file_put_contents(DATACHANGE_LOG, date("r")." Hello! \n", FILE_APPEND);
$stmt->rollBack();
}
I have a same result with valid and not valid data at my log file. It's the first row from try{} which means that rollback is not affective at file_put_contents. However if the data at queries not valid rollback working agains them and there is no changes at DB. But the row before rollback never works.
Errors are enabled but it doesn't show anything... I just can't give up I have to understand it...
Update 3
What is invalid data?
I've tried MySQL errors/table,row errors.
Why do I need this at all?
I'm learning and doing a lot of things that I don't need actually just to understand how it works. As I see now it throwing errors in MySQL itself so really not useful logger in this particular case. Anyway I've got my errors and here is it.
Working code:
try{
$this->_db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$this->_db->beginTransaction();
$stmt = $this->_db->prepare
QUERIES
$stmt->execute(array($var));
file_put_contents(DATACHANGE_LOG, date("r")." ".n307." UserID: ".$id."\n", FILE_APPEND);
$this->_db->commit();
}catch(PDOException $e){
file_put_contents(DATACHANGE_LOG, date("r")."Error". $e->getMessage()." UserID: ".$id."\n", FILE_APPEND);
if($this->_db->rollback())
header("Location: http://link");
}
header("Location: http://anotherlink");
There is nothing essentially different inside try..catch blocks. And your file writing code should be working the same way as outside, no difference.
The only issue I can think of is irrelevant to try..catch but to exceptions in general: a thrown exception terminates further code execution. Say, if there is an error in $stmt->rollBack(); - no code below will be executed. So, it's better to move a logger at the top of the block.

ActiveMQ/Stomp debug when a message disables a consumer

I am scratching my head trying to debug a PHP transaction that seems to error out one of my consumers. I can detect if my consumer is running by GREPping the process list, before I insert a new message, but no way of knowing what was in there before and what caused the fatal error.
My PHP consumer is roughly:
while($isRunning == true) {
try{
if($frame = $this->stomp->readFrame()) {
$body = $frame->body;
$this->stomp->ack($frame);
}
} catch(StompException $e) {
$msg = 'Stomp Monitor readFrame() Callback Fail: '.$e->getMessage();
error_log($msg);
}
}
Is there any way to catch fatal errors or anything that will break it out of the infinite loop?
Thanks,
Steve
Try setting a top level exception handler
Perhaps there is an exception that your not catching. Catch it and log it so you know why the process dies.

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