Data Validation

See Also

Category Data Editing
Default Catalog Visual FoxPro Catalog\Foundation Classes\Data Query
Class _datachecker
Base Class Custom
Class Library _datanav.vcx
Parent Class _custom
Sample ...\Samples\Vfp98\Solution\Ffc\conflicts.scx

Remarks

This class traps for data conflicts on buffered data.

To use, drop the class on a project or form or, from the Component Gallery Item Shortcut menu, select Add to Project or Add to Form. When you add the class to a form, you need to specify the appropriate property values. When you drop the class on a project, you can choose between adding the class or creating a subclass.

See Guidelines for Using Visual FoxPro Foundation Classes for more information on using foundation classes.

Properties, Events, Methods Description
HandleRecord method Compares the current value, old value, and original value on disk of each field, displaying a message box if a change or conflict is detected.
Syntax: HandleRecord(lnScope)
Return: nReturn
Arguments:
lnScope specifies the degree of validation:

0 = check for conflicts
1 = check for conflicts and verify changes
nReturn specifies the action taken:
0 = No Change
1 = Successful Change
2 = Unable to make change

String method Called by the HandleRecord method, returns a character equivalent of the passed value. Returns only a notification for memo fields.
Syntax: String(luValue)
Return: none
Arguments:
luValue specifies the value to be checked.
VerifyChanges method Prompts a user to save all changes made to a table or record.
Syntax: VerifyChanges( )
Return: none
Arguments: none
VerifyEachChange method Prompts a user to confirm each change made.
Syntax: VerifyEachChange( )
Return: none
Arguments: none
CheckcConflicts method Notifies a user when data has changed after record editing started.
Syntax: CheckcConflicts( )
Return: none
Arguments: none