fTrackFile (Function)

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Constants for the external files

Functions for managing external files

Handling the external files

Storing files in Android

Summary table: Managing the application directories according to the platform

fDetectRemovableStorage

fReadLineRegularExpression

fRemoveDir

fRename

fReportsAndQueriesDir

Special cases
WLanguage procedure

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fTrackFile (Function)

In french: fSurveilleFichier

Triggers the tracking of a file. In case of file modification, a specific procedure is run in a thread.

Example

// Name of file to track
sFileName is string = "C:\Temp\MyDir\MyFile.extension"
// The ProcessModification procedure will be called when the
// "C:\Temp\MyDir\MyFile.extension" file is modified.
IF fTrackFile(sFileName, ProcessModification, ...
ftCreateFile + ftModifyFile + ftDeleteFile + ...
ftRename) THEN
// Inform the user that the file will be tracked
Info("The " + sFileName + " file will be tracked.")
ELSE
// Inform the user that the file will not be tracked
Info("The " + sFileName + " file will not be tracked.")
END

// Code of the procedure
PROCEDURE ProcessModification(sFullName, sFileName, nAction, sFormerFileName)
sActionDesignation is string
// The designation of the action depends on nAction
SWITCH nAction
CASE ftCreateFile: sActionDesignation = "Creating files"
CASE ftDeleteFile: sActionDesignation = "Deleting files"
CASE ftModifyFile: sActionDesignation = "Modifying files"
CASE ftRename: sActionDesignation = "Renaming files"
END
// Add a line containing the information about the modification
// into the TABLE_MODIFICATIONS table
TableAddLine(TABLE_MODIFICATIONS, sFullName, sFileName, ...
sActionDesignation, sFormerFileName)

Syntax

<Result> = fTrackFile(<File name> , <Procedure name> [, <Modifications to notify>])

<Result>: Boolean

True if the tracking of the file is enabled,
False otherwise. To find out the error details, use ErrorInfo.

<File name>: Character string (with quotes)

Full name of the file to track.

<Procedure name>: Character string (with or without quotes)

Name of the WLanguage procedure ("callback" procedure) that will be called when a change is detected in the specified file.
This procedure has the following format:

PROCEDURE <Procedure name>([<Full name of modified file>
[ <, <Name of modified file> [, <Action> [, <Former file name>]]]])

where:
<Full name of modified file>: character string indicating the full path of the tracked file.
<Name of modified file>: character string indicating the name of the tracked file (after modification).
<Action>: Integer constant that can take the following values:
ftCreateFile The <Name of modified file> file was created.
ftModifyFile The <Name of modified file> file was modified.
ftRename The <Name of modified file> file was renamed.
ftDeleteFile The <Name of modified file> file was deleted.
<Former name>: Former name of the modified file if the action performed is a rename operation.
Versions 22 and later
Note: This procedure can be an internal procedure.
New in version 22
Note: This procedure can be an internal procedure.
Note: This procedure can be an internal procedure.

<Modifications to notify>: Optional Integer constant (or combination of constants)

Modifications performed in the file to track and for which the procedure must be run:
ftCreateFile The <Name of modified file> file was created.
ftModifyFile The <Name of modified file> file was modified.
ftRename The <Name of modified file> file was renamed.
ftDeleteFile The <Name of modified file> file was deleted.
ftAll All the possible actions will be tracked. Corresponds to ftCreateFile + ftModifyFile + ftRename + ftDeleteFile.

Remarks

Special cases

To stop tracking the file, use fTrackStop and fTrackStopAll.
To track the modifications performed on the content of a directory, use fTrackDirectory.
Limitations:
- Only 5 files can be tracked at the same time.
- You cannot track a file found at the root of a disk (for performance reasons).

WLanguage procedure

The WLanguage procedure is run in a WLanguage thread.
Caution: The following processes cannot be run in the threads:

opening windows with WLanguage functions such as Open, Use, Close, ... A specific management mode must be implemented if windows must be handled in the threads (very rare). See Managing the opening of a window in a secondary thread for more details.
managing events.
managing timers.

See Managing threads for more details.

Component : wd250std.dll