Developing Shared Applications

1. Developing Shared Applications Susanne Lefvert lefvert@mcs.anl.gov University of Chicago

2. Outline • Overview • Sharing State • Event Communication • SharedAppClient • DatastoreClient • Packaging and Installation • Example: Shared PDF • Exercises • Documentation

3. Shared Applications • Shared Browser • Browse the web together • Shared Presentation • View and control remote presentations • Shared VNC • Secured screen sharing • Question and Answer Tool • Remotely post questions and answers Allows individuals to use programs together from remote locations

4. Shared Applications

5. Sharing State Venue foo Client 1 Application Session State: foo foo Client 2 foo Client 3 * Communicating via SOAP calls

6. Event Communication Venue bar foo Client 1 Application Session foo bar EventChannel Client 2 EventChannel bar foo Client 3 * Communicating via GSITCP Sockets

7. SharedAppClient Your Application Venue SharedAppClient SharedApplicationIW Application Session EventChannel EventClient

8. SharedAppClient • Tool for developers • Hides details about • SOAP communication • Event communication • Logging • Data cache • Exception handling • API • AccessGrid.SharedAppClient • AccessGrid.SharedApplication.SharedApplicationIW http://www.mcs.anl.gov/fl/research/accessgrid/documentation/developer/api/

9. SharedAppClient API: Join() – Connect to an application session InitLogging() – Get object for logging Shutdown() – Shut down soap interface and event client SendEvent() – Distribute an event to all clients RegisterEventCallback() – Register callback for event SetData() – Set shared state GetData() – Get shared state UpdateDataCache() – Update cached data GetPublicId() – Get my unique id GetVenueURL() – Get venue url

10. DatastoreClient API: LoadData() – Get data from venue QueryMatchingFiles() – Get file names matching pattern GetFileData() – Get data description for a file Download() – Download file from venue Upload() – Upload file to venue RemoveFile() – Remove file from venue

11. Packaging and Installation • Create an application description file. • SharedMyApp.app • Create an Access Grid package. • SharedAppName.agpkg • Use agpm.py to install the application. • agpm.py --help • Open the package in the Venue Client • Start application sessions in the Venue Client. [application] name = SharedMyApp mimetype = application/x-ag-shared-myapp extension = sharedmyapp files = SharedMyApp.py, otherFile [commands] Open = %(python)s SharedMyApp.py -a %(appUrl)s

12. Example: Shared PDF

13. Example: Shared PDFSharedAppClient # Create shared application client self.sharedAppClient = SharedAppClient(name) self.log = self.sharedAppClient.InitLogging() # Get client profile clientProfile = ClientProfile(UserConfig.instance().GetProfile()) # Join the application session self.sharedAppClient.Join(appUrl, clientProfile) self.id = self.sharedAppClient.GetPublicId() # Register callbacks for external events self.sharedAppClient.RegisterEventCallback("openFile", self.OpenCallback) self.sharedAppClient.RegisterEventCallback(“changePage", self.ChangePageCallback)

14. Example: Shared PDFGet Current State State: URL to file and current page number # Get current state self.file = self.sharedAppClient.GetData(“file") self.pageNr = self.sharedAppClient.GetData(“page") if self.file: try: self.dataStoreClient.Download(self.file, "tmp") self.pdf.LoadFile("tmp") self.pdf.setCurrentPage(self.pageNr) except: self.log.exception("PdfViewer.__init__: Download failed %s"%(self.file))

15. Example: Shared PDF

16. Example: Shared PDFEvent Communication Event: type – “changePage”, data – unique ID and page number # -- sender --- def OnNextPageButton(self, event): '''Invoked when user clicks the next button.''' self.pageNr = self.pageNr + 1 self.pdf.setCurrentPage(self.pageNr) self.sharedAppClient.SendEvent(“changePage", (self.id, self.pageNr)) self.sharedAppClient.SetData("page", self.pageNr) # --- receiver --- def ChangePageCallback(self, event): ''' Invoked when a changePage event is received.''' id, self.pageNr = event.data # Ignore my own events if self.id != id: wxCallAfter(self.pdf.setCurrentPage, self.pageNr)

17. Example: Shared PDF

18. Example: Shared PDFDatastoreClient def PopulateCombobox(self, default = None): # Get pdf files from venue fileNames = [] wxBeginBusyCursor() try: self.dataStoreClient.LoadData() fileNames = self.dataStoreClient.QueryMatchingFiles("*.pdf") except: self.log.exception("FileSelectorDialog.PopulateCombobox: Failed.") wxEndBusyCursor() # Update combobox self.pdfList.Clear() for file in fileNames: self.pdfList.Append(file)

19. Example: Shared PDFPackaging and Installation 1. Create SharedPDF.app: 2. SharedPDF.py + SharedPDF.app => SharedPDF.agpkg (zip) 3. agpm.py --p SharedPDF.agpkg [application] name = Shared PDF mimetype = application/x-ag-shared-pdf extension = sharedpdf files = SharedPDF.py [commands] Open = %(python)s SharedPDF.py -v %(venueUrl)s -a %(appUrl)s

20. Starting Application Session

21. Exercises http://www.mcs.anl.gov/fl/research/accessgrid/documentation/tutorial/AGTk_2.4 Exercise 4 – Shared Applications: • Shared Stoplight • Shared Group Chat

22. Exercise 1: Shared Stoplight

23. Exercise 1: Shared Stoplight • Creating the application environment • Initializing the AG environment • Creating SharedAppClient • Joining the application session • Registering event callbacks • Retrieving initial state • Sending and receiving events • Setting application state

24. Exercise 1: Shared Stoplight Three Exercises: • Create an AG package, install, and start the application from the Venue Client. • Add a new button – yellow • Add a text field to change the title

25. Exercise 1: Shared Stoplight

26. Exercise 2: Shared Group Chat

27. Documentation • Contributed Software Page http://www.mcs.anl.gov/fl/research/accessgrid/wiki/moin.cgi/ContributedSoftware • Reference Materials http://www.mcs.anl.gov/fl/research/accessgrid/wiki/moin.cgi/DevelopingSharedApplications • Toolkit API http://www.mcs.anl.gov/fl/research/accessgrid/documentation/developer/api/