Error handling is the process of catching error and then taking appropriate action. When you create web application error handling is an important part. If your code lacks error checking code, your program look unprofessional and it will open to security risks.
Here are some different types of error handling methods:
· Use simple ‘die’ function.
· Custom error and error trigger
· Error reporting
Use die function
While writing your program you should check all possible condition and take appropriate action. Below example will just open the file.
<?php
$file=fopen("team.txt","r");
?>
Note: To prevent the user from getting this error message use die statement for handling errors as done in below example:
<?php
if(!file_exists("team.txt")) {
die("File cannot be found");
} else {
$file=fopen("team.txt","r");
}
?>
Note: It was a simple error handling mechanism to stop the program. However to stop the program is not always right way to go. Let’s take an alternative PHP function for error handling.
Creating a custom error Handler
You can write your own function for handling errors.PHP provides framework to define error handling. We simply create a function and call this function when an error occurs.
Syntax:
error_function(error_level,error_message, error_file,error_line,error_context);
Note:It this function two parameter is required(error_level, error_message) and others are optional(error_file , error_line, error_context).
|
Parameter |
Description |
|
error_level |
Specifies the error report level for the user-defined error and it must be a value number.(Required) |
|
error_message |
Specifies the error message for the user-defined error.(Required) |
|
error_file |
Specifies the name of the file in which error occurred (optional). |
|
error_line |
Specifies the line number in which error occurred (optional). |
|
error_context |
Specifies an array containing variables and their values when the error occurred.(optional) |
Error report level
These error report levels are the different types of error. They are given below:
Value | Constant | Description |
2 | E_WARNING | Non-fatal run-time errors. Execution of the script is not halted. |
8 | E_NOTICE | Run-time notices. The script found something that might be an error. |
256 | E_USER_ERROR | Fatal user-generated error. This is like an E_ERROR set by the programmer using the PHP function trigger_error(). |
512 | E_USER_WARNING | Non-fatal user generated warning. This is like an E_WARNING set by the programmer using the PHP function trigger_error |
1024 | E_USER_NOTICE | User-generated notice. This is like an E_NOTICE set by the programmer using the PHP function trigger_error |
4096 | E_RECOVERABLE_ERROR | Catchable fatal error. This is alike an E_ERROR but can be caught by a user defined handle. |
8191 | E_ALL | All errors and warnings, except level E_STRICT. |
Elena Glibart
31-Mar-2017