Navigation: ABC Library Reference > ASCIIViewerClass > AsciiViewerClass Methods >====== Init (initialize the ASCIIViewerClass object)  ====== |    |
Init( file, field, [filename], list control, error handler [, features] )
| Init | Initializes the ASCIIViewerClass object. |
| file | The label of the file to display. |
| field | The fully qualified label of the file field to display. |
| filename | The label of the file's NAME attribute variable. If omitted, the file has a constant NAME attribute. If null (''), the Init method prompts the end user to select a file. |
| list control | An integer constant, variable, EQUATE, or expression containing the control number of the LIST that displays the file contents. |
| error handler | The label of the ErrorClass object to handle errors encountered by this ASCIIViewerClass object. |
| features | An integer constant, variable, EQUATE, or expression that tells the ASCIIViewerClass object which features to implement; for example, printing (EnablePrint), searching (EnableSearch), or both. If omitted, no additional features are implemented. |
The Init method initializes the ASCIIViewerClass object and returns a value indicating whether it successfully accessed the file and is ready to proceed.
Implementation:
The Init method returns one (1) if it accessed the file and is ready to proceed; it returns zero (0) and calls the Kill method if unable to access the file and cannot proceed. If the Init method returns zero (0), the ASCIIViewerClass object is not initialized and you should not call its methods.
You can set the features value with the following EQUATEs declared in ASCII.INC. Pass either EQUATE to implement its feature (search or print), or add the EQUATEs together to implement both features.
EnableSearch BYTE(001b)
EnablePrint BYTE(010b)
Return Data Type: BYTE
Example:
PROGRAM
MAP
END
INCLUDE('ABASCII.INC') !declare ASCIIViewer Class
ViewWindow WINDOW('View an ASCII File'),AT(3,7,296,136),SYSTEM,GRAY
LIST,AT(5,5,285,110),USE(?AsciiBox),IMM
BUTTON('&Print'),AT(5,120),USE(?Print)
BUTTON('&Search'),AT(45,120),USE(?Search)
BUTTON('&Close'),AT(255,120),USE(?Close)
END
GlobalErrors ErrorClass !declare GlobalErrors object
Viewer AsciiViewerClass,THREAD !declare Viewer object
ViewerActive BYTE(False),THREAD !Viewer initialized flag
Filename STRING(255),THREAD !FileName variable
AsciiFile FILE,DRIVER('ASCII'),NAME(Filename),PRE(A1),THREAD
RECORD RECORD,PRE()
Line STRING(255)
END
END
CODE
GlobalErrors.Init !initialize GlobalErrors object
OPEN(ViewWindow) !open the window
!Initialize Viewer with:
ViewerActive=Viewer.Init( AsciiFile, | ! file label,
A1:line, | ! file field to display
Filename, | ! variable file NAME attribute
?AsciiBox, | ! LIST control number
GlobalErrors, | ! ErrorClass object
EnableSearch+EnablePrint) ! features to implement flag
IF ~ViewerActive THEN RETURN. !if init unsuccessful, don't
! call other Viewer methods
ACCEPT !If init succeeded, proceed
IF EVENT() = EVENT:CloseWindow
IF ViewerActive THEN Viewer.Kill. !If init succeeded, shut down
END
!program code
END
See Also: Kill