Expose "save" event in Office.js across platforms

[Yun_Wang]

@cody-lettau Thanks for the posting. Can you also describe how do you want the event fired when it is auto-save?

Thanks.

[Yun_Wang]

@cody-lettau Thanks for the posting. Can you also describe how do you want the event fired when it is auto-save?

Thanks.

[cody-lettau]

Hi @Yun_Wang - I think the best approach would be that an event is fired prior to the actual save occurring so that an add-in can do any pre-processing desired to the content and file data prior to it being saved to the server.

In our use case, we never want the unencrypted document to be saved to the server. This is for obvious reasons if the goal is data security/privacy. So in this case, we would want to be able to be notified when a save is about to occur, encrypt the document, and have that encrypted version saved to the server.

[Yashi55]

Please expose a BeforeSave event, so we can register and handle changes before the actual save is done. 

[Danny_G_FastClose]

The lack of a BeforeSave Event causes all sorts of problems for our Excel Addin. Please add!!

[Nick_Christie]

We need to include some state information for our Add-In in the workbook, whenever the workbook is saved. It doesn't make sense to store this state separately from the workbook because that would likely get out of sync. For example, we wouldn't be able to track if the workbook got copied or deleted. It might also be useful to know if the workbook was being autosaved, or explicitly saved by the user (outside of OneDrive, or with AutoSave turned off).