I went to my first ngSydney meetup on Wednesday night, and presented a short session on Office-Addin with AngularJS (I also throw in Graph API) and ran over my allocated time to 40 minutes.
I probably should have asked for 1hr.
Here is the PowerPoint presentation. Presentation: office-addin yo ngSydney
Also, check out all the examples on http://dev.office.com/
Graph API has Excel endpoints "coming soon". These REST endpoints will let your app reach inside a workbook/worksheet/range/cell and pull/push stuff in and out like JSON goodness.
Unfortunately, no Word REST API yet.
As I rushed through the demo some things perhaps wasn't as clear as I could explain.
1. There were two libraries/APIs - the Microsoft Graph REST API lets you talk to services across Office and eventually Microsoft space. You need to register an Azure App so Graph knows what permissions you are after. Your users need to authenticate and grant permission to your app to use the services that it is asking for.
2. The Office.js within a Office Add-In lets you talk to the current document, or mail within the Office App. You need to register/deploy the manifest.xml file with your Office 365, or through network share or group policy for Desktop Apps. The manifest describes what sort of permissions you are seeking on the current document, usually there is only Read or ReadWrite.
You can use Office.js and Graph API together as it was in my demo, or separately.
3. The 'app' I was running in the iframe for both Office 365 or Word 2013 is running out of https://localhost/ - I didn't stop to show this.
4. Authentication piece of the puzzle moves forward as well - next on the line is Progressive Permissions where an app can request more permissions on the spot and the user will be asked to allow additional permissions (write) on the go.
5. Office Addin is available in: Office 2013/2016, Office for Mac, Office for iOS. Not yet available on Office for Android. It also runs in Office Online (SharePoint Online, OneDrive, Docs.com) and within both Exchange Online (business) and Outlook.com (consumer).
Had a few awesome quotes: