I spoke about SharePoint Online and Office 365 here: SharePoint Online and Office365 Business Productivity.
Office 365 along with all its provided SaaS are spreading across the globe and a lot of companies depend on it dramatically in day--day business activities. That raises the need for business to build custom applications to extend and consume the available functionalities, to achieve that let us take a look into different preferences.
There are several ways to develop custom apps and extend the SharePoint Online Functionality:
- SharePoint Rest APIs: it is like CSOM it can be used for Online and On Premise and it allows you to make direct REST APIs call while in CSOM you can use the available functions and classes.
- Office 365 Rest APIs: Used mainly for Exchange and OneDrive and available for Office 365 only, there are some SDKs that are built on top of it but not providing the full functionalities.
- New announcement of SharePoint Framework
- No code solutions like Flow and PowerApps
It is worth mentioning too that you can use PowerShell Scripting to call SharePoint Online APIs.
Unsupported development options:
- Full trust code as used to develop for the On Premise is not an option for developing Online while it is still an option for development on premise.
- Sandbox: Microsoft recently announced the deprecation of sandbox which used to be sort of subset of full trusted code.
Quick steps to put you on the road for developing using CSOM:
- Install Visual Studio 2015.
- Download and install NuGet client and integrate it with Visual Studio https://dist.nuget.org/index.html
- Create project.
- Add NuGet package.
- Add reference.
- Call CSOM.
You can watch this video where I have started using CSOM: https://channel9.msdn.com/Blogs/MVP-Office-Servers-and-Services/Trigger-SharePoint-Online-CSOM
- SharePoint Online Planning Guide for Office 365
- To transform from Full trusted code to Add Ins
- Plan Customization for SharePoint Online
- Infrastructure from Mars and SharePoint from Venus
- Perform Basic Operations using CSOM -TechNet Wikis
- SharePoint 2013: Custom or Advance Paging Using Client Object Model +jQuery-TechNet Wikis
- SharePoint 2010: Using the Client Object Model with a Form Based Auth Site - different way-TecNet Wikis
- Office Dev PnP
Written by: John Naguib
Microsoft MVP, Solution Architect/Senior Consultant
Wiki Ninja Blogger, SharePoint Expert and Speaker.