What is the use of custom error tag in web.config file?
The '<customErrors>' tag in the web.config file is used to configure how the application handles and displays error messages to users when exceptions occur.
The '<customErrors>' tag allows you to define different error handling modes, specifying how errors should be handled and presented to users. It has the following attributes:
-
'mode': This attribute defines the error handling mode and can have one of the following values:
"Off": This mode disables custom error handling, and detailed error messages are shown to the user, including stack traces. This mode is typically used during development or debugging.
- "On": This mode enables custom error handling and displays a custom error page to the user when an exception occurs. The custom error page is defined using the <error> tag within the <customErrors> tag.
- "RemoteOnly": This mode is similar to "On", but the custom error page is shown only for remote users accessing the application. For local requests, detailed error messages are displayed. This mode is commonly used in production environments to provide a user-friendly error page to remote users while allowing detailed error messages for developers.
-
'defaultRedirect': This attribute specifies the URL of the custom error page to be displayed when an exception occurs. It is used when the 'mode' attribute is set to "On" or "RemoteOnly". You can specify a relative or absolute URL.
-
'<error>': This tag is used to define specific error pages for different HTTP status codes or exception types. It allows you to provide custom error pages tailored to specific errors. You can specify the 'statusCode' or 'exceptionType' attribute along with the 'redirect' attribute to define the error page for a specific error.
Here's an example of the '<customErrors>' tag in the web.config file:
<configuration>
<system.web>
<customErrors mode="On" defaultRedirect="~/ErrorPages/Error.aspx">
<error statusCode="404" redirect="~/ErrorPages/NotFound.aspx" />
<error statusCode="500" redirect="~/ErrorPages/InternalError.aspx" />
</customErrors>
</system.web>
</configuration>
In this example, the mode attribute is set to "On", which enables custom error handling. The 'defaultRedirect' attribute specifies the default error page to display for unhandled exceptions. Additionally, specific error pages are defined for HTTP status codes 404 (Not Found) and 500 (Internal Server Error).
By utilizing the '<customErrors>' tag, you can control how error messages are presented to users, improving the user experience and providing relevant information while handling exceptions gracefully.