 |
 | Home | Contact Us | FAQ | Search & Site Map | Link to Us |
 | Sign In | Join | Other 45 Sites in Network |
| HomeDiscussionsAccessExcelInfoPathOutlookPowerPointPublisherWordDirectoryUser Groups Related Topics Outlook ExpressInternet ExplorerWindowsMS Server ProductsMore Topics ... |
MS Office Forum / Outlook / Programming Add-Ins / October 2006ItemChange and Exchange synchronization
I am using the ItemChange event in my C# code to capture when an item is saved and then do something with it. The problem is I do not want to do this action when Exchange is syncing. Is there anyway to determine when exchange is doing its auto-sync so i can not run the code? Thanks so much No, the cached Exchange provider provides no notification. Why wouldn't you want to run your code? Does it matter whether a change occured because the current user modified an item or because it got modified on a different machine and the Exchange provider received the notification and updated the local copy? Dmitry Streblechenko (MVP) http://www.dimastr.com/ OutlookSpy - Outlook, CDO and MAPI Developer Tool >I am using the ItemChange event in my C# code to capture when an item is >saved and then do something with it. The problem is I do not want to do >this action when Exchange is syncing. Is there anyway to determine when >exchange is doing its auto-sync so i can not run the code? > Thanks so much Thanks Dmitry for your response. Well basically once a user does a save I capture the ItemChange event and log the item that was change to a local db. Then when they click a button I try to sync to the contact up to a server based on the values from the local db file. In addition to syncing from outlok I also sync down from the server to outlook and save the item. During the syncing I set a flag so anything that is saved will not trigged the ItemChange event, but once my sync process is complete, I change the flag to capture the next time someone modifies a contact. So the problem is about 30 secs after my sync process is complete and the flag is reset, Outlook syncs with exchange which causes the ItemChange event to fire and me to resave the item as modified in my local b file which triggers the whole process over again when nothing has really changed. Does that make sense? > No, the cached Exchange provider provides no notification. > Why wouldn't you want to run your code? Does it matter whether a change [quoted text clipped - 12 lines] >> exchange is doing its auto-sync so i can not run the code? >> Thanks so much Thanks Dmitry for your response. Well basically once a user does a save I capture the ItemChange event and log the item that was change to a local db. Then when they click a button I try to sync to the contact up to a server based on the values from the local db file. In addition to syncing from outlok I also sync down from the server to outlook and save the item. During the syncing I set a flag so anything that is saved will not trigged the ItemChange event, but once my sync process is complete, I change the flag to capture the next time someone modifies a contact. So the problem is about 30 secs after my sync process is complete and the flag is reset, Outlook syncs with exchange which causes the ItemChange event to fire and me to resave the item as modified in my local b file which triggers the whole process over again when nothing has really changed. Does that make sense? > No, the cached Exchange provider provides no notification. > Why wouldn't you want to run your code? Does it matter whether a change [quoted text clipped - 12 lines] >> exchange is doing its auto-sync so i can not run the code? >> Thanks so much Thanks Dmitry for your response. Well basically once a user does a save I capture the ItemChange event and log the item that was change to a local db. Then when they click a button I try to sync to the contact up to a server based on the values from the local db file. In addition to syncing from outlok I also sync down from the server to outlook and save the item. During the syncing I set a flag so anything that is saved will not trigged the ItemChange event, but once my sync process is complete, I change the flag to capture the next time someone modifies a contact. So the problem is about 30 secs after my sync process is complete and the flag is reset, Outlook syncs with exchange which causes the ItemChange event to fire and me to resave the item as modified in my local b file which triggers the whole process over again when nothing has really changed. Does that make sense? > No, the cached Exchange provider provides no notification. > Why wouldn't you want to run your code? Does it matter whether a change [quoted text clipped - 12 lines] >> exchange is doing its auto-sync so i can not run the code? >> Thanks so much Thanks Dmitry for your response. Well basically once a user does a save I capture the ItemChange event and log the item that was change to a local db. Then when they click a button I try to sync to the contact up to a server based on the values from the local db file. In addition to syncing from outlok I also sync down from the server to outlook and save the item. During the syncing I set a flag so anything that is saved will not trigged the ItemChange event, but once my sync process is complete, I change the flag to capture the next time someone modifies a contact. So the problem is about 30 secs after my sync process is complete and the flag is reset, Outlook syncs with exchange which causes the ItemChange event to fire and me to resave the item as modified in my local b file which triggers the whole process over again when nothing has really changed. Does that make sense? > No, the cached Exchange provider provides no notification. > Why wouldn't you want to run your code? Does it matter whether a change [quoted text clipped - 12 lines] >> exchange is doing its auto-sync so i can not run the code? >> Thanks so much I sam confused - why would ItemChange fire if you did not change it again? Or if a new change did not come from the EX server? Dmitry Streblechenko (MVP) http://www.dimastr.com/ OutlookSpy - Outlook, CDO and MAPI Developer Tool > Thanks Dmitry for your response. Well basically once a user does a save I > capture the ItemChange event and log the item that was change to a local [quoted text clipped - 26 lines] >>> exchange is doing its auto-sync so i can not run the code? >>> Thanks so much Thanks Dmitry, so what happens is I save the contact in the code, ItemChange fires, of course, but b/c my flag is set, I do not resave it again to my local db. But then it seems b/c I just saved the Contact about 30 seconds later the ItemChange event fires b/c it seems that Exchange is doing the synchronization. Does this make sense? > I sam confused - why would ItemChange fire if you did not change it again? > Or if a new change did not come from the EX server? [quoted text clipped - 34 lines] >>>> exchange is doing its auto-sync so i can not run the code? >>>> Thanks so much Hmmm.. I do not see that secondd event in the cached mode... I guess you could store a hash made out of the values that you care about (e.g .Email1Address + FileAs + ...) - if the hash is still the same, do nothing. Dmitry Streblechenko (MVP) http://www.dimastr.com/ OutlookSpy - Outlook, CDO and MAPI Developer Tool > Thanks Dmitry, so what happens is I save the contact in the code, > ItemChange fires, of course, but b/c my flag is set, I do not resave it [quoted text clipped - 43 lines] >>>>> code? >>>>> Thanks so much Good suggestion Dmitry, so does that mean there is no way to catch this exchange sync event programmatically within Outlook? If I triggered the exchange sync to happen so that I could control my flag and not save to my local db file, would I be able to prevent it from happening at another time besides when the user saves the item? Rog > Hmmm.. I do not see that secondd event in the cached mode... > I guess you could store a hash made out of the values that you care about [quoted text clipped - 53 lines] >>>>>> code? >>>>>> Thanks so much No, you wouldn't be able to know what exactly caused that event to fire. Dmitry Streblechenko (MVP) http://www.dimastr.com/ OutlookSpy - Outlook, CDO and MAPI Developer Tool > Good suggestion Dmitry, so does that mean there is no way to catch this > exchange sync event programmatically within Outlook? If I triggered the [quoted text clipped - 60 lines] >>>>>>> code? >>>>>>> Thanks so much Thanks Dmitry for your help, I figured I would post back what I ended up implementing. For whatever reason i had forgotten, code bloat possibly, that I had kept a lastsyncdate variable so in the ItemChange handler I check the lastmodificationTime of the outlook object against the last sync date, if the modtime is greater I save to my db file otherwise I do not nothing. Thanks, Rog > No, you wouldn't be able to know what exactly caused that event to fire. > [quoted text clipped - 67 lines] >>>>>>>> code? >>>>>>>> Thanks so much I think I spoke to soon on this one. if the exchange server time is off or it is trying to sync objects down from exchange the lastmodificationtime will be greater that the local sync date time. back to square one. Anyone have any other ideas? Rog > Thanks Dmitry for your help, I figured I would post back what I ended up > implementing. For whatever reason i had forgotten, code bloat possibly, [quoted text clipped - 77 lines] >>>>>>>>> so i can not run the code? >>>>>>>>> Thanks so much Do you read the LastModificationTime property from the item itself? Dmitry Streblechenko (MVP) http://www.dimastr.com/ OutlookSpy - Outlook, CDO and MAPI Developer Tool >I think I spoke to soon on this one. if the exchange server time is off or >it is trying to sync objects down from exchange the lastmodificationtime [quoted text clipped - 83 lines] >>>>>>>>>> not run the code? >>>>>>>>>> Thanks so much >I think I spoke to soon on this one. if the exchange server time is off or >it is trying to sync objects down from exchange the lastmodificationtime >will be greater that the local sync date time. > back to square one. Anyone have any other ideas? Basically what you must do is make sure you call the Item.Save method *only* when you have actually changed something significant in the item. Calling Item.Save writes the item unconditionally, which resets LastMod; any time you do this, Exchange will come right along behind you, sync the item, and save it again. In other words, when Exchange is the provider, there is already one thing running that will unconditionally re-write an item once for every time something else writes that same item [since it was last synced by Exchange.] If your code does this *too*, it sets-up an endless i/o cycle. To manage this I check the Item.Saved property before calling the Item.Save method; I only call Item.Save if Item.Saved = False... but there are at least a couple of hitches... One is, if you are working with AppointmentItem or TaskItem, and you update a recurrence pattern, Item.Saved will not always reflect this, though you must call Save to keep the changes to recurrence. Another is that any Item property assignment will cause Saved to return false, even if the value is unchanged by the assignment. e,g., Dim tmp tmp = Item.SomeProperty Item.SomeProperty = tmp ' the following condition will evaluate as True If (Item.Saved = False) Then [..] So for every Item property I assign, I first check for inequality... but again there are caveats... Merely checking for exact programmatic equality will leave you in almost the same cycle, for instance, Exchange likes a trailing blank line on the Body property, and it likes to format phone numbers. To me these levels of change aren't worth the i/o it would take to push them to SQL Server, so my comparison routines are written to ignore them accordingly. Also, dates can pose a special problem, depending on where you store them outside of OL/Exchange, due to low-level differences in the way they are stored. e.g., ' assume rs is an ADODB.Recordset connected to SQL Server rs!LastModificationTime = Item.LastModificationTime rs.Update rs.Requery ' simulate retrieving the record at a later time ' the following condition may *not* evaluate as True ' assume the item has not been written since its LastMod was stored If (rs!LastModificationTime = Item.LastModificationTime) Then [..] Long story short, though you can't determine which module caused ItemChange to fire, you can expect -- indeed you must expect -- that Exchange will routinely do so without significantly changing the item's content. As such, IMHO, it's more constructive to evaluate what has been written, rather than what was responsible for writing it. -Mark > Rog > [quoted text clipped - 79 lines] >>>>>>>>>> not run the code? >>>>>>>>>> Thanks so much As a rule of thumb, one should never us "=" when comparing datetime properties due to the round-off errors - always compare the absolute value of a difference between two values. E.g. if the absolute value of a difference is less than 1 millisecond, the values are the same for all practical purposes. Dmitry Streblechenko (MVP) http://www.dimastr.com/ OutlookSpy - Outlook, CDO and MAPI Developer Tool >>I think I spoke to soon on this one. if the exchange server time is off or >>it is trying to sync objects down from exchange the lastmodificationtime [quoted text clipped - 142 lines] >>>>>>>>>>> can not run the code? >>>>>>>>>>> Thanks so much |
Reply to this Message |
 Sign In
 Join
 My Latest Posts My Monitored Threads My Blog My Photo Gallery My Profile My Homepage Start New Thread Enable EMail Alerts Rate this Thread
|
©2008 Advenet LLC Privacy Policy - Terms of Use
This website includes both content owned or controlled by Advenet as well as content owned or controlled by third parties.