file watcher

filewatcherexample.cs

	/**
	 * Initialize the File Trigger Watcher which will monitor the fullFilePath
	 * directory and when the BPM writes a new file it will read the file and
	 * based on the contents of the file we can do certain actions think of it as a
	 * bridge to have the BPM Communicate with our C# Code
	 *
	 * @type 	Custom Function
	 * @return	void
	 */
	private void InitializeFileTriggerWatcher()
	{
		// Get Trigger File Path
		string wtPath = this.GetWriteTriggerFilePath("IT", "WTPath");

		// Generate the Path Variable which will consist of the file path
		// and the USER currently logged in this way we do not collide with others
		// in case you had multiple Handheld devices.
		string fullFilePath = System.IO.Path.Combine(wtPath, "trigger-" + ((Ice.Core.Session)(this.oTrans.Session)).UserID.ToString() );

		// Delete the File if it exists for Cleanup
		// Otherwise the Changed Event might occur twice
		File.Delete(fullFilePath);

		// Create Watcher
		watcher = new FileSystemWatcher();
		watcher.Path = Path.GetDirectoryName(fullFilePath);
		watcher.NotifyFilter = NotifyFilters.LastWrite | NotifyFilters.CreationTime;
		watcher.Filter = Path.GetFileName(fullFilePath);
		watcher.Changed += new FileSystemEventHandler(NewFileTriggerEvent);
		watcher.EnableRaisingEvents = true;
	}

	/**
	 * Destroy the File Watcher and Dispose
	 *
	 * @type 	Custom Function
	 * @return	void
	 */
	private void DestroyFileTriggerWatcher()
	{
		watcher.Changed -= new FileSystemEventHandler(NewFileTriggerEvent);
		watcher.Dispose();
	}

	/**
	 * When the FileWatcher event detects a new file then this function
	 * will be triggered to Handle the Event
	 *
	 * @var 	source object
	 * @var 	e Event
	 * @type 	Custom Function
	 * @return	void
	 */
	private void NewFileTriggerEvent(object source, FileSystemEventArgs e)
	{
		if (File.Exists(e.FullPath.ToString()) == false)
		{
			return;
		}

		// Initialize variables
		string date 	= string.Empty;
		string eventKey = string.Empty;
		string company 	= string.Empty;
		string user 	= string.Empty;

		// There should never be a problem because if we are in this
		// Event that means the file is there But just an extra precaution step
		try {

			if (File.Exists(e.FullPath.ToString()) == false)
			{
				return;
			}

			// Read the file and get the values
			string[] values = File.ReadAllText(e.FullPath.ToString()).Split(',');
			date 		= values[0];
			eventKey 	= values[1];
			company 	= values[2];
			user 		= values[3];
		}
		catch {
			//playSound("ERROR"); // must let the user know that his process has been stopped
			//MessageBox.Show("There was an issue with Reading Trigger File. This could mean there is another instance of HH01 running Packout.");
			//
			return;
		}

		// Do Something Special with the Event
		switch (eventKey)
		{
			case "PACKOUT_EXCEPTION":
				playSound("ERROR");
				break;

			case "LABEL_VALIDATION_IF_REQUIRED":
				this.isLabelValidationApproved = true;
				break;
		}

		File.Delete(e.FullPath.ToString());
	}