trigger_error

(PHP 4 >= 4.0.1, PHP 5, PHP 7, PHP 8)

trigger_error — Generar un mensaje de error/advertencia/aviso de nivel de usuario

Descripción

trigger_error(string $message, int $error_level = E_USER_NOTICE): bool

Se usa para provocar una condición de error de usuario, se puede utilizar junto con el gestor de errores interno o con una función definida por el usuario que ha sido establecida como el nuevo gestor de errores (set_error_handler()).

Esta función es útil cuando se necesita generar una respuesta en particular a una excepción en tiempo de ejecución.

Parámetros

message: El mensaje de error designado para este error. Está limitado a 1024 bytes de longitud. Cualquier carácter más allá de los 1024 será truncado.
error_level: El tipo de error designado para este error. Sólo funciona con la familia de constantes E_USER, y por defecto es E_USER_NOTICE.

Valores devueltos

Esta función devuelve false si se especifica un error_level erróneo, si no true.

Ejemplos

Ejemplo #1 Ejemplo de trigger_error()

Véase set_error_handler() para un ejemplo más extenso.

<?php
if ($divisor == 0) {
    trigger_error("No se puede dividir por cero", E_USER_ERROR);
}
?>

Notas

Advertencia

Las entidades HTML en message no son escapadas. Use htmlentities() en el mensaje si el error se va a mostrar en un navegador.

Ver también

error_reporting() - Establece cuáles errores de PHP son notificados
set_error_handler() - Establecer una función de gestión de errores definida por el usuario
restore_error_handler() - Recupera la función de gestión de errores previa
Las constantes de niveles de error

Improve This Page

Learn how improve this page • Submit a Pull Request • Report a Bug

＋add a note

User Contributed Notes 5 notes

down

someone at attbi dot com ¶

20 years ago

the idea is never to give out file names, line numbers, and cryptic codes to the user. Use trigger_error() after you used set_error_handler() to register your own callback function which either logs or emails the error codes to you, and echo a simple friendly message to the user.



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');

}

down

Howard Yeend ¶

14 years ago

trigger_error always reports the line and file that trigger_error was called on. Which isn't very useful.



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"

down

richard at 2006 dot atterer dot net ¶

18 years ago

Beware, trigger_error() is absolutely useless for transporting your own function's error messages in $php_errormsg:

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');

down

aydin dot kn12 at gmail dot com ¶

9 years ago

If error_type is E_USER_ERROR then trigger_error throw FATAL ERROR and script stopped after this line.

<?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...

?>

down

PhpMyCoder ¶

13 years ago

For those of you looking to use your own file or line number in the error (possibly using debug_backtrace()) instead of the ones created by trigger_error(), here is a solution:
Create a custom function to handle E_USER_ERRORs that simply outputs the error type and message, while excluding the line number and file trigger_error() reports. You may also configure it to handle user warnings and notices if necessary (I did in the example below).

<?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!

＋add a note