In the event of an error, the On Error Goto errHandler statement instructs the procedure to stop executing your code at the point at which the. When an error occurs using On Error GoTo [label], the error handling behaviour returns to the default behaviour i.e. “On Error GoTo. The On Error Goto ErrorHandler line defines how Apache OpenOffice Basic proceeds in the event of an error. The Goto ErrorHandler ensures.
On error goto errorhandler - that interruptOut of Memory (Error 7) 0
On Error GoTo Resume Statement
Enables an error-handling routine after an error occurs, or resumes program execution.
GoTo Labelname: If an error occurs, enables the error-handling routine that starts at the line "Labelname".
Resume Next: If an error occurs, program execution continues with the statement that follows the statement in which the error occurred.
GoTo 0: Disables the error handler in the current procedure.
Local: "On error" is global in scope, and remains active until canceled by another "On error" statement. "On Local error" is local to the routine which invokes it. Local error handling overrides any previous global setting. When the invoking routine exits, the local error handling is canceled automatically, and any previous global setting is restored.
The On Error GoTo statement is used to react to errors that occur in a macro.
Impressum (Legal Info) Invalid Procedure Call or Argument (Error 5)
Correct handling of error situations is one of the most time-consuming tasks of programming. Apache OpenOffice Basic provides a range of tools for simplifying error handling.
The instruction is the key to any error handling:
The line defines how Apache OpenOffice Basic proceeds in the event of an error. The ensures that Apache OpenOffice Basic exits the current program line and then executes the code.
The command continues the program from the line that follows where the error occurred in the program after the code in the error handler has been executed:
Use the command to specify a jump point for continuing the program after error handling:
The term Proceed is a label. It could be for example, A The syntax for label names is the same as for variable names.
To continue a program without an error message when an error occurs, use the following format:
Use the command with caution as its effect is global.
Queries Regarding Error Information
In error handling, it is useful to have a description of the error and to know where and why the error occurred:
- The variable contains a number identifying the type of error that has occurred.
- The variable contains a description of the error.
- The variable contains the line number where the error occurred.
shows how the error information can be displayed in a message window.
|VBA: Whereas VBA summarizes the error messages in a global object called , Apache OpenOffice Basic provides the , and variables.|
The status information remains valid until the program encounters a or command, whereupon the information is reset.
|VBA: In VBA, the method of the object resets the error status after an error occurs. In Apache OpenOffice Basic, this is accomplished with the or commands.|
Tips for Structured Error Handling
Both the definition command, , and the return command, , are variants of the construct.
If you want to cleanly structure your code to prevent generating errors when you use this construct, you should not use jump commands without monitoring them.
Care should be taken when you use the command as this dismisses all open error messages.
The best solution is to use only one approach for error handling within a program - keep error handling separate from the actual program code and do not jump back to the original code after the error occurs.
The following code is an example of an error handling procedure:
This procedure begins with the definition of an error handler, followed by the actual program code. At the end of the program code, the error handling is deactivated by the call and the procedure implementation is ended by the command (not to be confused with ).
The example first checks if the error number corresponds to the expected number (as stored in the imaginary constant) and then handles the error accordingly. If another error occurs, the system outputs a warning. It is important to check the error number so that unanticipated errors can be detected.
The call at the end of the code resets the status information of the error (the error code in the system variables) so that an error occurring at a later date can be clearly recognized.
Thought differently: On error goto errorhandler
|An error occurred while mounting /sys/bus/usb/drivers|
|Disk i/o error|
|ACCESS ERROR SITE OR PAGE NOT FOUND|
|On error goto errorhandler|
On Error Goto
Enables an error-handling routine and specifies the location of the routine within a procedure.
On Error statement
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Enables an error-handling routine and specifies the location of the routine within a procedure; can also be used to disable an error-handling routine.
On Error GoToline
On Error Resume Next
On Error GoTo 0
The On Error statement syntax can have any of the following forms:
|On Error GoToline||Enables the error-handling routine that starts at line specified in the required lineargument.|
The line argument is any line label or line number.
If a run-time error occurs, control branches to line, making the error handler active.
The specified line must be in the same procedure as the On Error statement; otherwise, on error goto errorhandler, a compile-time error occurs.
|On Error Resume Next||Specifies that when a run-time error occurs, control goes to the statement immediately following the statement where the error occurred and execution continues. Use this form rather than On Error GoTo when accessing objects.|
|On Error GoTo 0||Disables any enabled error handler in the current procedure.|
If you don't use an On Error statement, any run-time error that occurs is fatal; that is, an error message is displayed and execution stops.
An "enabled" error handler is one that is turned on by an On Error statement; an "active" error handler is an enabled handler that is in the process of handling an error. If an error occurs while an error handler is active (between the occurrence of the error and a Resume, Exit Sub, Exit Function, or Exit Property statement), the current procedure's error handler can't handle the error. Control returns to the calling procedure.
If the calling procedure has an enabled error handler, on error goto errorhandler, it is activated to handle the error. If the calling procedure's error handler is also active, control passes back through previous calling procedures until an enabled, but inactive, error handler is found, on error goto errorhandler. If no inactive, enabled error handler is found, on error goto errorhandler, the error is fatal at the point at which it actually occurred.
Each time the error handler passes control back to a calling procedure, that procedure becomes the current procedure. After an error is handled by an error handler in any procedure, execution resumes in the current procedure at the point designated by the Resume statement.
An error-handling routine is not a Sub procedure or Function procedure. It's a section of code marked by a line label or line number.
Error-handling routines on error goto errorhandler on the value in the Number property of the Err object to determine the cause of the error. The error-handling routine should test or save relevant property values in the Err object before any other error can occur or before a procedure that might cause an error is called. The property values in the Err object reflect only the most recent error. The error message associated with sprers.eu is contained in sprers.euption.
On Error Resume Next causes execution to continue with the statement immediately following the statement that caused the run-time error, on error goto errorhandler with the statement immediately following the most recent call out of the procedure containing the On Error Resume Next statement. This statement allows execution to continue despite a run-time error. You can place the error-handling routine where the error would occur, rather than transferring control to another location within the procedure. An On Error Resume Next statement becomes inactive when another procedure is called, so you should execute an On Error Resume Next statement in each called routine if you want inline error handling within that routine.
The On Error Resume Next construct may be preferable to On Error GoTo when handling errors generated during access to other objects. Checking Err after each interaction with an object removes ambiguity about which object was accessed by the code. You can be sure which object placed the error code in sprers.eu, as well as which object originally generated the error (the object specified in sprers.eu).
On Error GoTo 0 disables error handling in the current procedure. It doesn't specify line 0 as the start of the error-handling code, even if the procedure contains a line numbered 0. Without an On Error GoTo 0 on error goto errorhandler, an error handler is automatically disabled when a procedure is exited.
To prevent error-handling code from running when no error has occurred, place an Exit Sub, Exit Function, on error goto errorhandler, or Exit Property statement immediately before the error-handling routine, as in the following fragment:
Here, the error-handling code follows the Exit Sub statement and precedes the End Sub statement to separate it from the procedure flow. Error-handling code can be placed anywhere in a procedure.
Untrapped errors in objects are returned to the controlling application when the object is running as an executable file. Within on error goto errorhandler development environment, untrapped errors are only returned to the controlling application if the proper options are set. See your host application's documentation for a description of which options should be set during debugging, how to set them, and whether the host can create classes.
If you create an object that accesses other objects, you should try to handle errors passed back from them unhandled. If you cannot handle such errors, map the error code in sprers.eu to one of your own errors, and then pass them back to the caller of your object. You should specify your error by adding your error code to the vbObjectError constant. For example, if your error code isassign it as follows:
System errors during calls to Windows dynamic-link libraries (DLL) or Macintosh code resources don't raise exceptions and cannot be trapped with Visual Basic error trapping. When calling DLL functions, you should check each return value for success or failure (according to the API specifications), and in the event of a failure, check the value in the Err object's LastDLLError property. LastDLLError always returns zero on the Macintosh.
This example first uses the On Error GoTo statement to specify the location of an error-handling routine within a procedure. In the example, an attempt to delete an on error goto errorhandler file generates error number The error is handled in the error-handling routine, and control is then returned to the statement that caused the error. The On Error GoTo 0 statement turns off error trapping.
The On Error Resume Next statement is then used to defer error trapping so that the context for the error generated by the next statement can be known for certain. Note that sprers.eu is used to clear the Err object's properties after the error is handled.
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