HL7PlusFileWatcher

*All example code is in Visual Basic.Net

'Declare your file watcher at the class level

Private WithEvents oWatcher As HL7PlusFileWatcher = Nothing

'Start the File Watcher object

Private Sub ButtonStart(sender As Object, e As EventArgs) Handles ButtonStart.Click

Try

oWatcher = New HL7PlusFileWatcher("C:\HL7\SomeFile.hl7")

oWatcher.RefreshInterval = HL7PlusFileWatcher.UPFWRefreshInterval.RI10Seconds

oWatcher.StartMonitor()

Catch ex As Exception

MessageBox.Show(ex.Message, "Error Starting")

End Try

End Sub

'Stop the File Watcher object

Private Sub ButtonStop(sender As Object, e As EventArgs) Handles ButtonStop.Click

Try

If Not IsNothing(oWatcher) Then

If oWatcher.IsRunning Then

oWatcher.StopMonitor()

End If

Catch ex As Exception

MessageBox.Show(ex.Message, "Error Stopping")

End Try

End Sub

Enumerator Name: UPFWRefreshInterval

Description: Used to set the refresh interval (in milliseconds) when the HL7PlusFileWatcher is running

Members:

RI5Seconds = 5000

RI10Seconds = 10000

RI20Seconds = 20000

RI30Seconds = 30000

RI45Seconds = 45000

RI1Minute = 60000

Property Name	Data Type	Description
Exists	Boolean	Evaluates whether FileName exists or not.
FileName	String	The full path / filename the object is watching. NOTE: Set when you create the object or call Reset(strFileName).
InitialFileDate	Date	The LastModified date/time of FileName when the object was created, or last reset.
InitialFileSize	Long	The size of FileName in bytes when the object was created or last reset.
IsRunning	Boolean	Indicates whether the object is actively monitoring FileName. See StartMonitor(), StopMonitor()
MonitoredFileInformation	HL7PlusFileInfo	Returns a NEW HL7PlusFileInfo object for FileName.
RefreshInterval	UPFWRefreshInterval	Determines how often the object will check FileName when it is running.

Method:	Reset(strFileName)
Paramters:	1: strFileName (String) A new FileName to watch.
Return Value:	Boolean
Description:	Resets the HL7PlusFileWatcher object. Sets a new FileName and if it WAS running when called, restarts the monitor

Method:	ResetInitialStateValues()
Paramters:	None
Return Value:	None
Description:	Resets InitialFileDate and InitialFileSize properties to their current values for FileName.

Method:	StartMonitor()
Paramters:	None
Return Value:	Boolean
Description:	Starts watching FileName (checking every RefreshInterval) and raises events if the state of the file changes. NOTE: The monitoring activity is done in a separate thread.

Method:	StopMonitor()
Paramters:	None
Return Value:	Boolean
Description:	If the object IsRunning it will Stop all monitoring activity.

Event:

FileModified (oFileInformation, blnAutoReset)

Paramters:

1: oFileInformation (HL7PlusFileInfo) A HL7PlusFileInfo object for FileName.

2: blnAutoReset (Boolean) Initial Value = False- Do you want to call ResetInitialStateValues() or keep receiving the event.

Condition:

When the HL7PlusFileWatcher is running this event will be fired if either the File Size or Last Modified Date changes for FileName. Set blnAutoReset to TRUE or you will keep receiving this event every RefreshInterval.

Event:	FileNotFound()
Paramters:	None
Condition:	Fired every RefreshInterval if FileName does not exist.

Event:	RefreshError( oException )
Paramters:	1: oException (HL7PlusException)
Condition:	Fired if an error occurs during the monitoring activity.

This object class uses our standard HL7PlusException Class interface for error handling wherever possible.

See the HL7PlusException Implementation Reference

Class Name:	HL7PlusFileWatcher
HL7+ Category:	Unrestricted
Description:	General purpose event driven stateless file watching object