The simplest way to test out XFormDBF is to launch it from the VFP command
window with the following command line:
When called in this manner, i.e. with no arguments, XFormDBF makes a number
of default assumptions. Specifically, it assumes the default action
('Prompt' with interactive modal dialog), the default configuration (functionid
= 'xformdbfdf'), and the default meta-file ('xformdbf.dbf' in the current
XFormDBF supports the following 6 optional arguments:
- one of the reserved action codes, 'prompt',
'promptn', 'promptnx', 'run', or 'runc'. Recommended macro definitions for these codes are in
xformdbf.h, along with brief descriptions. The default is 'prompt'
(defined as macro XFDB_ACPRM in the xformdbf.h include file), which means to use a modal dialog for interactive operation.
- functionid for the state (form configuration) to be restored/saved.
If empty string, use the default form configuration, i.e.bypass state restoration and saving.
If empty non-string value or omitted, use the default state function id, determined by evaluating the
Saver property, svp_dfltfuncexp.
- object reference to the generic Commander controlling the meta-file for state saving and restoration.
If null or omitted, use the default Commander object determined by evaluating the property
svp_dfltcmdrexp. If an object reference is provided, it should point to a Commander.
For character string values, this argument specifies the meta-file path to be opened automatically by allocating a temporary Commander object.
- optional input file path. If specified and non-empty, the input file
will be held to this specification, regardless of the configuration that may be restored.
If empty or omitted, the input file specification will be restored from
a previous saved state.
- optional output file path. If specified and non-empty, the output file will be held to this specification, regardless of the configuration that may be restored.
If empty or omitted, the output file specification will be restored from
a previous saved state.
- optional object reference to the target ErrHandler to be used.
If supplied, hold on to the given ErrHandler in ehp_targobj. If NULL, empty, or omitted, let ehp_targ* properties determine the target ErrHandler requirements and any related initializations.
The following actions are supported as the first
argument to XFormDBF:
- (the default) launches an interactive, modal dialog. (A modal dialog
is one that requires you to exit from the form before you can activate
another window in the same process.)
- launches an interactive, Non-modal (i.e. modeless) dialog. This
action does not produce a meaningful function return value, because the form
continues to exist beyond the command that launched it. (A modeless
dialog is useful because it allows you to run multiple applications or forms
at the same time in the same process, switching between applications simply
by clicking on their forms.) This action also allows you to access the
VFP Command Window while XFormDBF is active, if you are running under the
VFP Development System.
- interactive, Non-modal (modeless) dialog, with READ EVENTS. The same as PromptN, but this action also causes the wrapper function to execute a READ EVENTS, so it doesn't return
until the form is closed, which triggers a CLEAR EVENTS. Consequently, the wrapper function's return value
does provide a meaningful success flag result in this mode.
This is primarily intended for standalone testing purposes, in order to avoid problems due to limitations in VFP's RETURN TO ... mechanism, which can affect some abnormal error handling situations.
- Restores a previously saved configuration and runs the transformation,
non-interactively. In this case, the form is deliberately hidden from
view, except for its progress messages in the status bar and WAIT
window. The Run action bypasses the usual state-saving logic, so the
saved configuration will not be altered, even if overriding input/output file arguments
- Clones and Runs. First this clones the associated template output file belonging to a previously saved configuration, and then
it runs the transformation non-interactively. If an explicit output file argument is supplied, this will be the output destination.
The RunC action bypasses the usual state-saving logic, so the saved configuration
will not be altered, even if overriding input/output file arguments
XFormDBF returns a success flag result, which is set to .T. only if completely successful.
In cases of errors, a mechanism is provided for obtaining detailed error
Copyright © 2000 - 2002, SpaceTime Systems