| Category | Application |
| Default Catalog | Visual FoxPro Catalog\Foundation Classes\Application |
| Class | _datasession |
| Base Class | Custom |
| Class Library | _app.vcx |
| Parent Class | _custom |
| Sample | ...\Samples\Vfp98\Solution\Ffc\environ.scx |
Remarks
This class is used to manage data sessions and handle data updates in all forms or formsets in the current data session. It enables an Application object to easily iterate through sessions to provide Windows-closing behavior during Exit or Shutdown. It also provides generic QueryUnload behavior for forms and formsets, and generic session-wide Update and Revert code. You can use it to evaluate whether any data has been changed in a session before you use your own conflict handling procedure.
This class works with free tables as well as tables in databases. Observe the transactions limit (5).
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, Visual FoxPro places the class on the form. You can then specify the appropriate property values and provide any necessary input and output objects. 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 |
| iDataChangedMode property | Specifies the type of data change performed.
0 - Everything changed. Default: 0 |
| iSavedSessionID property | Specifies integer value representing the ID of the saved session. Default: 1 |
| lSuccess property | Specifies whether the data operation (update) was successful. Default: .T. |
| lUseTransactions property | Specifies whether to wrap the updating routine in a transaction. Note Only tables in a database container (.dbc) are affected in transactions. Default: .T. |
| DataChanged method | Checks if data has changed. Syntax: DataChanged( ) Return: none Arguments: none |
| DataFlush method | Ensures that the active control will have its current contents "recognized" even if you choose to update from a toolbar button while a grid has the focus. Syntax: DataFlush( ) Return: none Arguments: none |
| GetActiveControlRef method | Returns the truly active control, loRealActiveControl, in cases where the current active control is a Grid. Syntax: GetActiveControlRef(toActiveControl) Return: loRealActiveControl Arguments: toActiveControl specifies the current control. |
| GetMessageBoxTitle method | Returns a portion of the titlebar text specifying the name of the message. Syntax: GetMessageBoxTitle( ) Return: cTitlebarText Arguments: none |
| QueryUnload method | Provides dialog boxes to manage data change decisions. Syntax: QueryUnload(tlDataChangeAlreadyConfirmed, toForm, tlNoShow) Return: liResult Arguments: tlDataChangeAlreadyConfirmed specifies whether data has been changed toForm specifies the form. tlNoShow specifies whether to display the form. liResult specifies the MESSAGEBOX or value. |
| RestoreSessionID method | Restores the data session. Syntax: RestoreSessionID Return: none Arguments: none |
| Revert method | Reverts the session to original data. Syntax: Revert(tlUserChoiceAlreadyConfirmed, tlDataChangeAlreadyConfirmed, toForm, tlNoShow) Return: none Arguments: tlUserChoiceAlreadyConfirmed specifies whether to display a confirmation dialog. tlDataChangeAlreadyConfirmed specifies whether to display a confirmation dialog. toForm specifies the form. tlNoShow specifies whether to display the form. |
| SetSessionID method | Sets the data session. Syntax: SetSessionID( ) Return: none Arguments: none |
| Update method | Updates data. Syntax: Update(tlUserChoiceAlreadyConfirmed, tlDataChangeAlreadyConfirmed, toForm, tlNoShow) Return: none Arguments: tlUserChoiceAlreadyConfirmed specifies whether to display a confirmation dialog. tlDataChangeAlreadyConfirmed specifies whether to display a confirmation dialog. toForm specifies the form. tlNoShow specifies whether to display the form. |