Automatic management of errors

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Overview
Automatic management of errors
Implementing the automatic management of errors
Running the error process ("CASE ERROR" in the code)
Running a procedure for processing the error:
Displaying the error and exiting from the application:
Display error and resume input in the current window
Displaying the error and giving the decision to the user:
Returning the XXX value and displaying the error
Customizing the windows for automatic management of errors
Functions for automatic management of errors

WINDEV

WEBDEV

WINDEV Mobile

Others

See also

Automatic management of exceptions

Automatic management of errors

Overview

The management of errors can be customized by process.

No more "IF ... NOT", "IF ErrorOccurred ..." and other nested tests that made the code difficult to understand.

You can choose to use automated error processing or advanced management via the different WLanguage functions.

Important: The automatic management of errors and exceptions operates for the process for which it was defined.

Automatic management of errors

Implementing the automatic management of errors

To implement the automatic management of errors:

In the code editor, display the process where the errors must be managed: initialization code, click code, procedure, ...
In the code header, clck "If Error: by program".
The window that is displayed allows you to specify the type of automatic process to perform:

Remarks:

The code for managing the error found in the current process has priority over the automatic processes in the following cases:
- Test of a function such as "IF NOT xxxx=True or False"
- Test of errors with the ErrorOccurred variable.
  The management code of the error found in the current process does not have priority over the automatic processes: the error process of the code AND the automatic process will be run in any case.
ErrorChangeParameter can be used for advanced error management.

Running the error process ("CASE ERROR" in the code)

If this option is selected, a code line is added to the current code "CASE ERROR: ". The code lines following this statement will be run when an error occurs in the previous code lines. This option is recommended to group all the error processes that may occur.

Running a procedure for processing the error:

If this option is selected, the specified procedure will be automatically run to process the error when an error occurs in the current process. This option is recommended if a procedure used to process the errors is already found in your application. This procedure will be automatically called when an error occurs. No test to run.

This procedure can return one of the constants found in the table below.

Depending on the constant returned, WINDEV, WEBDEV or WINDEV Mobile will perform the corresponding process.


*opRetry*	The function that triggered the error is re-run. This constant is not available in Java.
*opCancel*	The function that triggered the error returns an error and the code continues to run.
*opEndProcess*	The function that triggered the error returns an error and the current process stops. Equivalent to the following code line: IF NOT <HFSQL function> THEN ReturnToCapture()
*opEndProgram*	The function that triggered the error returns an error and the program stops. Equivalent to the following code line: IF NOT <Function> THEN EndProgram()
*opRelaunchProgram*	Ends the application and automatically restarts the application. This constant is not available.

Displaying the error and exiting from the application:

If this option is selected, the following window will be automatically displayed if an error occurs in the application:

This window allows the user to:

Copy the error details into the clipboard (to transmit these details to the application provider for example)
Stop the application
Automatically restart the application once it has been stopped. This option is not available in Java.

Remark: if the "Feedback" component is included in the application (directly or via the "?" menu), the error report can be sent to the application provider.

Display error and resume input in the current window

If this option is selected, the following window will be automatically displayed if an error occurs in the application:

This window allows the user to:

Copy the error details into the clipboard (to transmit these details to the application provider for example)
Stop the application
Cancel the operation: the current process is canceled. The current window of the application is displayed.
Automatically restart the application once it has been stopped.

Remark: if the "Feedback" component is included in the application (directly or via the "?" menu), the error report can be sent to the application provider.

Displaying the error and giving the decision to the user:

If this option is selected, the following window will be automatically displayed if an error occurs in the application:

This window allows the user to:

Copy the error details into the clipboard (to transmit these details to the application provider for example)
Stop the application
Cancel the operation: the current process is canceled. The current window of the application is displayed.
Retry the operation: the operation that triggered the error will be canceled then re-run.
Automatically restart the application once it has been stopped. This option is not available in Java.

Remark: if the "Feedback" component is included in the application (directly or via the "?" menu), the error report can be sent to the application provider.

This option and "Display the error and resume the input in the current window" have the same operating mode.

Returning the XXX value and displaying the error

If this option is selected, RESULT XXX will be automatically performed when an error occurs in the code.

The following values can be returned:

-1
0
Empty string ("")
FALSE
NULL
TRUE

The error can also be displayed.

Customizing the windows for automatic management of errors

By default, the windows for managing the errors, the exceptions and the assertions are included in the application. These windows are available in English and in French.

To customize these windows (or to translate them), all you have to do is import the corresponding windows into your project:

Select:
- On the "Project" pane, in the "Project" group, expand "Import" and select "WINDEV elements and their dependencies"
- On the "Project" pane, in the "Project" group, expand "Import" and select "WINDEV Mobile elements and their dependencies"
Select the directory of the elements to import: "Programs\Data\Preset windows\Assertion - Error - Exception".

Select the windows to import:

WINDEV	WINDEV Mobile	Type of window

WD_DisplayAssert.wdw	WM_DisplayAssert.WPW	Window for managing the assertions
WD_DisplayError.wdw	WM_DisplayError.WPW	Window for managing the errors
WD_DisplayException.wdw	WM_DisplayException.WPW	Windows for managing the exceptions
WD_ErrorTemplate.wdt		Template used by the WINDEV windows.

Validate. The windows are included in your project. These windows will be automatically used and they will replace the default windows.

Remark: To use the default windows, all you have to do is delete the imported windows from your project.

Functions for automatic management of errors

The functions for automatic management of errors are as follows:


ErrorChangeParameter	Configures the automatic behavior that will be implemented if an error occurs in the current process.
ErrorInfo	Retrieves information about the last error that occurred in a function of a WINDEV, WINDEV Mobile or WEBDEV component.
ErrorPropagate	Propagates a non-fatal error that can be processed by the calling code if the management of non-fatal errors was enabled for this code (in the code editor or by ErrorChangeParameter).
ErrorRestoreParameter	Restores the error process of a process.
ErrorThrow	Throw a non-fatal error.

Related Examples:

Training (WINDEV): WD Auto Error Management

[ + ] The "WD Automatic Management of Errors" example is an educational example about the automatic management of errors.
This example presents the fatal and non-fatal errors on several levels.

Training (WINDEV): WD Managing the Java errors

[ + ] WINDEV enables you to develop Java applications without even knowing Java.
You benefit from the power and from the automated processes of the WINDEV environment.
One of the most useful automated processes is the automatic management of errors.
This example presents the operating mode and the implementation of the mechanism for managing the WINDEV errors.
Some illustrations allow you to understand the simplification performed when implementing this feature.
This project is configured to generate a Java archive.