Php вызов ошибки

<?php
interface IException
{
/* Protected methods inherited from Exception class */
public function getMessage(); // Exception message
public function getCode(); // User-defined Exception code
public function getFile(); // Source filename
public function getLine(); // Source line
public function getTrace(); // An array of the backtrace()
public function getTraceAsString(); // Formated string of trace

/* Overrideable methods inherited from Exception class */

public function __toString(); // formated string for display
public function __construct($message = null, $code = 0);
}

abstract class

CustomException extends Exception implements IException
{
protected $message = 'Unknown exception'; // Exception message
private $string; // Unknown
protected $code = 0; // User-defined exception code
protected $file; // Source filename of exception
protected $line; // Source line of exception
private $trace; // Unknownpublic function __construct($message = null, $code = 0)
{
if (!$message) {
throw new $this('Unknown '. get_class($this));
}
parent::__construct($message, $code);
}

public function

__toString()
{
return get_class($this) . " '{$this->message}' in {$this->file}({$this->line})\n"
. "{$this->getTraceAsString()}";
}
}
?>

Now you can create new exceptions in one line:

<?php
class TestException extends CustomException {}
?>

Here's a test that shows that all information is properly preserved throughout the backtrace.

<?php
function exceptionTest()
{
try {
throw new TestException();
}
catch (TestException $e) {
echo "Caught TestException ('{$e->getMessage()}')\n{$e}\n";
}
catch (Exception $e) {
echo "Caught Exception ('{$e->getMessage()}')\n{$e}\n";
}
}

echo

'<pre>' . exceptionTest() . '</pre>';
?>

Here's a sample output:

Caught TestException ('Unknown TestException')
TestException 'Unknown TestException' in C:\xampp\htdocs\CustomException\CustomException.php(31)
#0 C:\xampp\htdocs\CustomException\ExceptionTest.php(19): CustomException->__construct()
#1 C:\xampp\htdocs\CustomException\ExceptionTest.php(43): exceptionTest()
#2 {main}

<?php
ob_start();
try {
/*contains all page logic
and throws error if needed*/
...
} catch (Exception $e) {
ob_end_clean();
displayErrorPage($e->getMessage());
}
?>

<?php
set_error_handler(function($errno, $errstr, $errfile, $errline){
if($errno === E_WARNING){
// make it more serious than a warning so it can be caught
trigger_error($errstr, E_ERROR);
return true;
} else {
// fallback to default php error handler
return false;
}
});

try {

// code that might result in a E_WARNING
} catch(Exception $e){
// code to handle the E_WARNING (it's actually changed to E_ERROR at this point)
} finally {
restore_error_handler();
}
?>

‘If an exception is not caught, a PHP Fatal Error will be issued with an “Uncaught Exception …” message, unless a handler has been defined with set_exception_handler().’

These two sentences seem a bit contradicting about what happens ‘when a catch matching the thrown exception’s class is not present’ (and the second sentence is actually correct).

<?php
try{
try {
throw new \Exception("Hello");
} catch(\Exception $e) {
echo $e->getMessage()." catch in\n";
throw $e;
} finally {
echo $e->getMessage()." finally \n";
throw new \Exception("Bye");
}
} catch (\Exception $e) {
echo $e->getMessage()." catch out\n";
}
?>

The output is:

Hello catch in
Hello finally
Bye catch out

<?phptry {
throw new Error( "foobar" );
// or:
// throw new Exception( "foobar" );
}
catch (Throwable $e) {
var_export( $e );
}?>

function

manager()
{
employee();
}

function

<?php
try {
echo "try block<br />";
throw new Exception("test");
} catch (Exception $ex) {
echo "catch block<br />";
} finally {
echo "finally block<br />";
}// try block
// catch block
// finally block
?>

<?php
try {
echo "try block<br />";
throw new Exception("test");
} catch (Exception $ex) {
echo "catch block<br />";
exit(1);
} finally {
echo "finally block<br />";
}// try block
// catch block
?>

<?php

$name

= "Name";//check if the name contains only letters, and does not contain the word nametry
{
try
{
if (preg_match('/[^a-z]/i', $name))
{
throw new Exception("$name contains character other than a-z A-Z");
}
if(strpos(strtolower($name), 'name') !== FALSE)
{
throw new Exception("$name contains the word name");
}
echo "The Name is valid";
}
catch(Exception $e)
{
throw new Exception("insert name again",0,$e);
}
}

catch (

Exception $e)
{
if ($e->getPrevious())
{
echo "The Previous Exception is: ".$e->getPrevious()->getMessage()."<br/>";
}
echo "The Exception is: ".$e->getMessage()."<br/>";
}?>

When exception is thrown from 'finally' block, it overrides the original not-caught (or re-thrown) exception. So the behavior is similar to 'return': value returned from 'finally' overrides the one returned earlier. And the original exception is automatically appended to the exceptions chain, i.e. becomes 'previous' for the new one. Example:
<?php
try {
try {
throw new Exception('thrown from try');
} finally {
throw new Exception('thrown from finally');
}
} catch(Exception $e) {
echo $e->getMessage();
echo PHP_EOL;
echo $e->getPrevious()->getMessage();
} // will output:
// thrown from finally
// thrown from try
?>

Example with re-throwing:
<?php
try {
try {
throw new Exception('thrown from try');
} catch (Exception $e) {
throw new Exception('thrown from catch');
} finally {
throw new Exception('thrown from finally');
}
} catch(Exception $e) {
echo $e->getMessage();
echo PHP_EOL;
echo $e->getPrevious()->getMessage();
} // will output:
// thrown from finally
// thrown from catch
?>

The same happens even if explicitly pass null as previous exception:
<?php
try {
try {
throw new Exception('thrown from try');
} finally {
throw new Exception('thrown from finally', null, null);
}
} catch(Exception $e) {
echo $e->getMessage();
echo PHP_EOL;
echo $e->getPrevious()->getMessage();
} // will output:
// thrown from finally
// thrown from try
?>

Also it is possible to pass previous exception explicitly, the 'original' one will be still appended to the chain, e.g.:
<?php
try {
try {
throw new Exception('thrown from try');
} finally {
throw new Exception(
'thrown from finally',
null,
new Exception('Explicitly set previous!')
);
}
} catch(Exception $e) {
echo $e->getMessage();
echo PHP_EOL;
echo $e->getPrevious()->getMessage();
echo PHP_EOL;
echo $e->getPrevious()->getPrevious()->getMessage();
} // will output:
// thrown from finally
// Explicitly set previous!
// thrown from try
?>

This seems to be true for versions 5.6-8.2.

And turn on a more verbose error handler function when you need to debug your scripts. In my init.php scripts I always have:

if (_DEBUG_) {

set_error_handler ('debug_error_handler');

}

else {

set_error_handler ('nice_error_handler');

}

eg:

main.php:

<?php

include('functions.php');

$x = 'test';

doFunction($x);

?>



functions.php:

<?php

function doFunction($var) {

if(is_numeric($var)) {

/* do some stuff*/

} else {

trigger_error('var must be numeric');

}

}

?>



will output "Notice: var must be numeric in functions.php on line 6"

whereas "Notice: var must be numeric in main.php on line 4" would be more useful

here's a function to do that:

<?php
function error($message, $level=E_USER_NOTICE) {

$caller = next(debug_backtrace());

trigger_error($message.' in <strong>'.$caller['function'].'</strong> called from <strong>'.$caller['file'].'</strong> on line <strong>'.$caller['line'].'</strong>'."\n<br />error handler", $level);

}

?>



So now in our example:

main.php:

<?php

include('functions.php');

$x = 'test';

doFunction($x);

?>



functions.php:

<?php

function doFunction($var) {

if(is_numeric($var)) {

/* do some stuff*/

} else {

error('var must be numeric');

}

}

function

error($message, $level=E_USER_NOTICE) {

$caller = next(debug_backtrace());

trigger_error($message.' in <strong>'.$caller['function'].'</strong> called from <strong>'.$caller['file'].'</strong> on line <strong>'.$caller['line'].'</strong>'."\n<br />error handler", $level);

}

?>



now outputs:

"Notice: var must be numeric in doFunction called from main.php on line 4"

ini_set('track_errors', TRUE);
function x() { trigger_error('MY ERROR'); }
@x();
echo "Error 1: \\"$php_errormsg\\"\\n";
@file_get_contents('/nonexisting');
echo "Error 2: \\"$php_errormsg\\"\\n";

This outputs:

Error 1: ""
Error 2: "failed to open stream: No such file or directory"

This behaviour is consistent with the description of $php_errormsg, which says that the variable will only be available within the scope in which the error occurred. The problem can be worked around with a custom error handler like the one below. However, I'm undecided whether changing the language in this way is good:

function errHandler($errno, $errstr, $errfile, $errline) {
global $php_errormsg; $php_errormsg = $errstr;
}
set_error_handler('errHandler');

<?php

$msg

= 'This is the test message for echo';trigger_error('Error message', E_USER_ERROR); // Script stopped after this line...echo $msg; // This line does not appear...?>

When you use trigger_error with your own error handler, the class instances are destroyed (don't know how to say it better, I am not an expert).

So, if you try to call a class function from within the error handler function, you will get 'Call to a member function on a non-object' error, even if this function works perfectly in the rest of your script.

Solution : re-use the xxx = new yyy to re-create the instance in the beginning of your error handler ... and then you can call the class functions you want !

<?php
function error_handler($level, $message, $file, $line, $context) {
//Handle user errors, warnings, and notices ourself
if($level === E_USER_ERROR || $level === E_USER_WARNING || $level === E_USER_NOTICE) {
echo '<strong>Error:</strong> '.$message;
return(true); //And prevent the PHP error handler from continuing
}
return(false); //Otherwise, use PHP's error handler
}

function

trigger_my_error($message, $level) {
//Get the caller of the calling function and details about it
$callee = next(debug_backtrace());
//Trigger appropriate error
trigger_error($message.' in <strong>'.$callee['file'].'</strong> on line <strong>'.$callee['line'].'</strong>', $level);
}//Use our custom handler
set_error_handler('error_handler');//-------------------------------
//Demo usage:
//-------------------------------
function abc($str) {
if(!is_string($str)) {
trigger_my_error('abc() expects parameter 1 to be a string', E_USER_ERROR);
}
}abc('Hello world!'); //Works
abc(18); //Error: abc() expects parameter 1 to be a string in [FILE].php on line 31
?>

This is a pretty simple concept and I'm sure most of you know this, but for those that don't, let it serve as a good example!

function badgirl(){
trigger_error("shame on me",E_USER_ERROR);
return true;
}

$sheis = @badgirl();
echo "You will never see this line - @ only supress message, not a control flow";

so in my error handler class i have the following in the constructor:

function ErrorHandler()
{
$this->error_messages = array();
error_reporting (E_ALL);
set_error_handler(array($this,"assignError"));
}

and my assignError method:
//accept the required arguments
function assignError($errno, $errstr, $errfile, $errline)
{
//get the error string
$error_message = $errstr;
//if in debug mode, add line number and file info
if(ErrorHandler::DEBUG())
$error_message .= "<br>".basename($errfile).",line: ".$errline;

switch ($errno)
{
//if the error was fatal, then add the error
//display an error page and exit
case ErrorHandler::FATAL():
$this->setType('Fatal');
$this->addError($error_message);
Display::errorPage($this->errorMessages());
exit(1);
break;
//if it was an error message, add a message of
//type error
case ErrorHandler::ERROR():
$this->setType('Error');
$this->addError($error_message);
break;
//if it was a warning, add a message of type
//warning
case ErrorHandler::WARNING():
$this->setType('Warning');
$this->addError($error_message);
break;
//if it was some other code then display all
//the error messages that were added
default:
Display::errorRows($this->errorMessages());
break;
}
//return a value so that the script will continue
//execution
return 1;
}

the key part there is the 'default' behaviour. i found that if i call trigger_error with anything other than E_USER_ERROR, E_USER_WARNING or E_USER_NOTICE, then error code '2' is passed to the handler method. so when it is time to print all my non-fatal errors, like 'password and confirm password don't match' or something, i call ErrorHandler::printAllErrors()

function printAllErrors()
{
trigger_error("",2);
}

which leads to the default behaviour in my switch statement in the assignError method above. the only problem with this is that the weird bug 'Problem with method call' that occurs with some static method calls (that one person on the bug lists said was fixed and another said wouldn't be fixed until version 5) also produces error code 2!! i have just taken to suppressing these errors with @, because despite the alledged problem with the method call, the script still seems to execute fine.

iain.

Eg. E_USER_ERROR will terminate the script while E_USER_NOTICE will not.

<?php
/**
* Behaves like trigger_error, but appends part of a stack trace to the error
* message. This allows you to see where trigger_error was called from, instead
* of just seeing the file and line number of the call to trigger_error.
*
* @param error_msg The designated error message for this error
* @param error_type The designated error type for this error (E_USER_*)
* @param context Number of stack frames to append, defaults to 1
* @return FALSE if wrong error_type is specified, TRUE otherwise
*/
function trigger_error_with_context($error_msg, $error_type, $context = 1) {
$stack = debug_backtrace();
for ($i = 0; $i < $context; $i++)
{
if (false === ($frame = next($stack))
break;
$error_msg .= ", from " . $frame['function'] . ':' . $frame['file'] . ' line ' . $frame['line'];
}
return trigger_error($error_msg, $error_type);
}
?>

<?phpfunction myErrorHandler($errno, $errstr, $errfile, $errline){
switch ($errno) {
case E_USER_ERROR:
if ($errstr == "(SQL)"){
// handling an sql error
echo "<b>SQL Error</b> [$errno] " . SQLMESSAGE . "<br />\n";
echo "Query : " . SQLQUERY . "<br />\n";
echo "On line " . SQLERRORLINE . " in file " . SQLERRORFILE . " ";
echo ", PHP " . PHP_VERSION . " (" . PHP_OS . ")<br />\n";
echo "Aborting...<br />\n";
} else {
echo "<b>My ERROR</b> [$errno] $errstr<br />\n";
echo " Fatal error on line $errline in file $errfile";
echo ", PHP " . PHP_VERSION . " (" . PHP_OS . ")<br />\n";
echo "Aborting...<br />\n";
}
exit(1);
break;

case

E_USER_WARNING:
case E_USER_NOTICE:
}
/* Don't execute PHP internal error handler */
return true;
}// function to test the error handlingfunction sqlerrorhandler($ERROR, $QUERY, $PHPFILE, $LINE){
define("SQLQUERY", $QUERY);
define("SQLMESSAGE", $ERROR);
define("SQLERRORLINE", $LINE);
define("SQLERRORFILE", $PHPFILE);
trigger_error("(SQL)", E_USER_ERROR);
}set_error_handler("myErrorHandler");// trigger an sql error
$query = "SELECT * FROM tbl LIMIT 1";
$sql = @mysql_query($query)
or sqlerrorhandler("(".mysql_errno().") ".mysql_error(), $query, $_SERVER['PHP_SELF'], __LINE__);?>

If this is a wrong approach, waiting for comments, if its not, use it!

<?
function catch($errno, $errstr, $errfile, $errline){
$GLOBALS['throw'] = $errstr;
$GLOBALS['throw_info'] = array(
'Message'=>$errstr
,'Code'=>$errno
,'Line'=>$errline
,'File'=>$errfile
,'Trace'=>debug_backtrace()
);

}
set_error_handler('catch');

function badgirl(){
if(true){ //error occure
trigger_error("BadGirlWithError",E_USER_NOTICE); // as throw with notice
return; // ...because trigger_error does not stop the function
}else{
return true;
}
}

// Try
$GLOBALS['throw'] = null; // ...try...
$sheis = badgirl(); //could be @badgirl, display_errors is something else, this just the handling
// ..try
if($GLOBALS['throw']){ // This actually catch re-throws too...
switch($GLOBALS['throw']){ // Catch
case 'GoodGirlException':
die('No bad girl today!');
break;
case 'BadGirlWithError':
die('Bad girl has some error');
break;
default:
return; // or you can make another trigger_error and re-throw another 'exception' or some other action
}
}
echo "You will never see this line - @ only supress message, not a control flow";
echo "Wrong! You could see this:)";

?>

.mano