4D Doc Center : CT ON ERROR

4D Chart v13

CT ON ERROR


CT ON ERROR ( method )

Parameter	Type	Description
method	String	Method to execute

Description

The CT ON ERROR command installs method as the method for managing 4D Chart errors. After the installation of the error handling method, 4D Chart calls method when a 4D Chart error occurs.

If method is an empty string, no method is called and error handling returns to 4D Chart.

When 4D Chart calls method, it returns three parameters ($1, $2, and $3) that can be used to manage the error.

Parameter	Type	Description
$1	Longint	Represents the 4D Chart area in which the error took place. If the error is not specific to a 4D Chart area, $1 equals 0.
$2	Longint	Holds the error number. Equivalent of a call to CT Error.
$3	Text	Contains the text of the error. Equivalent of a call to CT Error.

If you plan to compile your database, you should declare these paramer types as follows:

 C_LONGINT($1;$2)

 C_TEXT($3)

Example

This example shows the installation of an error-handling method.

CT ON ERROR("CHART ERROR")

The following method is CHART ERROR. This method tests $1 to determine whether an error occurred in area and then presents an alert box with the error number and message.

 C_LONGINT($1;$2)

 C_TEXT($3)

 

 If($1=Area)

    ALERT("An error occurred in the 4D Chart area 'Area'.")

 End if

 ALERT("Error number "+String($2)+Char(13)+$3)