HOnError (Function)

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Management of databases

Operating mode of custom errors

Using a class method to customize the errors

Customizing the default error windows

Customizing the default error pages

Related examples

See also

HOnError (Function)

In french: HSurErreur

Not available with this kind of connection

Customizes the management of HFSQL errors.

WINDEV, WEBDEV and WINDEV Mobile propose an automatic management of errors. The automatic management of errors can be disabled or enabled for one or more data files, for one or more types of errors. To do so, use HOnError and specify an empty string for the name of window, page or procedure. See Assisted management of HFSQL errors for more details.

The management of HFSQL errors must be programmed by HOnError. The management of HFSQL errors is not automatically taken account. HOnError is used to customize the management of HFSQL errors by running a specific procedure or window for example.

The automatic management of errors is not available for the stored procedures. HOnError is not available in the stored procedures.

The automatic management of errors is not available for the stored procedures.

Versions 24 and later

HOnError can be used to manage the error in a stored procedure.

New in version 24

HOnError can be used to manage the error in a stored procedure.

Note: From version 19, HFSQL is the new name of HyperFileSQL.

Versions 17 and later

This function is now available for iPhone/iPad applications.

New in version 17

This function is now available for iPhone/iPad applications.

Versions 18 and later

This function is now available in Windows Store apps mode.

New in version 18

This function is now available in Windows Store apps mode.

Versions 20 and later

This function is now available for the Java applications.

This function is now available in Android Widget mode.

This function is now available for Android applications.

Onlu the loss of connection can be customized.

New in version 20

This function is now available for the Java applications.

This function is now available in Android Widget mode.

This function is now available for Android applications.

Onlu the loss of connection can be customized.

This function is now available for the Java applications.

This function is now available in Android Widget mode.

This function is now available for Android applications.

Onlu the loss of connection can be customized.

Versions 21 and later

This function is now available in Universal Windows 10 App mode.

New in version 21

This function is now available in Universal Windows 10 App mode.

Example

See additional examples

// Customize the lock errors
// The OnLockError procedure is called
// when a lock error occurs for all the files
HOnError("*", hErrLock, "OnLockError")

// Re-enable the automatic management
// of all the errors on all the data files
HOnError("*", hErrAll)

// Re-enable the automatic management
// of the lock errors on Customer file
HOnError("Customer", hErrLock)

Syntax

<Result> = HOnError(<File name> , <Type of error> [, <Name of Procedure/Window/Page>])

<Result>: Boolean

True if the operation was successfully performed,
False otherwise. HError returns more details about the problem.

<File name>: Character string (with or without quotes)

Name of data file used. If this parameter is equal to "*" the customization will be applied to all data files found in the analysis or defined by programming.

<Type of error>: Constant or combination of constants

Type of error to configure.
hErrDatabaseAccess Configures the access errors to an HFSQL Client/Server database (access forbidden by HNoDatabaseAccess).
This constant is not available.
hErrLock Configure the lock errors.
This constant is not available.
hErrDuplicates Configure the duplicate errors.
This constant is not available.
hErrIntegrity Configure the integrity errors.
This constant is not available.
hErrModify Configure a modification conflict.
This constant is not available.
hErrPassword Configure the password errors (wrong password).
This constant is not available.
hErrConnectionLoss Configure the errors caused by a loss of connection with the HFSQL server.
This constant is not available.
hErrIndex Configures the indexing errors (re-indexing in progress during the file access).
This constant is not available.
hErrNeedValue Configure the errors caused by a mandatory input with no data (OLE DB and some native accesses).
This constant is not available.
hErrAll Configure all previous errors (except hErrIndex).
This constant is not available.

<Name of Procedure/Window/Page>: Optional character string

Corresponds to:
Name of window or procedure to call when a <Type of error> error occurs.
Name of page or procedure to call when a <Type of error> error occurs.
Name of object method if HOnError is called in a method of this object.
Versions 20 and later
Name of procedure to call when a <Type of error> error occurs.
New in version 20
Name of procedure to call when a <Type of error> error occurs.
Name of procedure to call when a <Type of error> error occurs.
Parameter not specified. If "Enable the automatic HyperFileSQL help" is checked in the project, the default window or page for automatic management of errors is used for the specified type of error and for the specified data file.Parameter not specified. If "Enable the automatic HFSQL help" is checked in the project, the default window or page for automatic management of errors is used for the specified type of error and for the specified data file.
Empty string. In this case, the automatic management of errors will be disabled.
Note: To disable the automatic management of errors, you also have the ability to uncheck "Enable the automatic HyperFileSQL help" in the project. Note: To disable the automatic management of errors, you also have the ability to uncheck "Enable the automatic HFSQL help" in the project.
Note: In some cases (loss of connection errors for example), the procedure/window/page will be run during the next call to the WLanguage function following the event that triggered the error.
Only some of the windows/pages for the automatic management of errors are available. The automatic management of errors is disabled for these errors.

Special case: using a window, a page or a procedure found in a component: The following syntax must be used:
Procedure:

HOnError(<File name>, <Type>, ...
"<Component>.<Name of set of procedures>.<Procedure name>")

Window:

HOnError(<File name>, <Type>, "<Component>.<Window name>")

Page:

HOnError(<File name>, <Type>, "<Component>.<Page name>")

If a loss of connection occurs, to ask for reconnection, this procedure must call HReconnect.

Remarks

Operating mode of custom errors

The procedure, window or page used to customize the error must return one of the following constants:


opRetry	The function that triggered the error is re-run.
opCancel	The function that triggered the error returns an error as if the assisted management was disabled. Note: For the errors of loss of connection, the error is fatal.
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()` This constant is not available.
opEndProgram	The function that triggered the error returns an error and the program stops. Equivalent to the following code line: `IF NOT <HFSQL function> THEN EndProgram()`
opRelaunchProgram	The program stops and the application is automatically restarted. This constant is not available.

If a loss of connection occurs, to ask for reconnection, HReconnect must be used in the procedure called by HOnError.

Using a class method to customize the errors

<Name of procedure or window> can also correspond to a method of an object if HOnError is called in a method of this object. All you have to do is specify the name of the method to use (without using the object name as prefix).

When the method is called by the HFSQL engine, a fatal error occurs if the object used during the call to HOnError is no longer allocated.

Customizing the default error windows

The default error windows are supplied (as well as their WLanguage code) for information in the "\Programs\Data\Preset windows\HyperFileSQL - Automatic help windows" directory.The default error windows are supplied (as well as their WLanguage code) for information in the "\Programs\Data\Preset windows\HFSQL - Automatic help windows" directory.

These windows can be included in your projects, they can be customized and passed in parameter to HOnError.

See Assisted management of HFSQL errors for more details.

Customizing the default error pages

The default error pages are supplied (as well as their WLanguage code) for information in the "\Programs\Data\Preset pages\HyperFileSQL - Automatic help pages" directory.The default error pages are supplied (as well as their WLanguage code) for information in the "\Programs\Data\Preset pages\HFSQL - Automatic help pages" directory.

These pages can be included in your projects, customized and passed in parameter to HOnError.

See Assisted management of HFSQL errors for more details.

Related Examples:

Training (WINDEV): WD Managing HFSQL Errors

[ + ] The "WD Managing HFSQL Errors" example presents the management of HFSQL errors (duplicate, integrity).
This example explains how to customize the process when an error occurs.

Component : wd240hf.dll