SharePoint Add-ins (SharePoint App) - Part One

First of all, Microsoft has changed the name “app for SharePoint” to “SharePoint Add-ins”.

New name for apps for SharePoint

The first important point in this series to understand is Tenancy.

Tenancy

A SharePoint Tenancy is a set of site collections. These sets of site collections are administrated as a unit.

SharePoint Tenancy in Office 365

When any organization/company purchases licenses of Office 365 for SharePoint sites (SharePoint Online) Office 365 creates the new tenancy. The users who access the tenancy are called Tenants.

When new tenancy is created in Office 365, for SharePoint an administrative site collection is created. This site collection is accessible to the SharePoint online administrators (also called Tenant administrators).

This SharePoint Admin site is similar to the Central Admin application in SharePoint on-premises as.

Figure 1. SharePoint Admin Center in Office 365

On the left side, there are settings for SharePoint features like InfoPath, BCS, apps, etc.

SharePoint Tenancy in On-Premises

The concept of Tenancy is introduced in SharePoint 2010. In On-Premises, farm-level default tenancy is created in the background. This farm-wide tenancy enables the installation of SharePoint apps in on-premises farms since apps are always installed and run within the context of tenancy.

Basics of SharePoint Add-ins

1. SharePoint Add-ins are stand-alone components implemented to solve specific requirements and can be added on multiple sites.
2. SharePoint Add-in code never runs in SharePoint. All custom code is either executed in the client machine or in the cloud or in another server depending upon which type of SharePoint Add-ins we are implementing.
3. SharePoint Add-in code is authenticated and runs under a separate identity. I’ll explain in more detail in upcoming articles.
4. We, developers, need to make decisions depending on the scenario/requirement and which type of Add-ins we need to develop.
5. In SharePoint 2013 everything is Add-ins/App means features in SharePoint like List, Libraries, etc.
6. Following are a few examples of SharePoint Add-ins
   • Site Creation Wizard - Approval mechanism: Employees of the company/organization can request the creation of sites/workspaces and requests will be sent to a specific group of people to approve.
   • Feedback App: Where end users of the site can give feedback to site administrators.
7. App Catalog
   • Apps are stored in specific sites called App Catalogs. Once the App catalog site is created, we can use it to upload the apps that we developed so that those apps will be available for the users to install those apps.
   • In An on-premises environment, the App-catalog site is specific to the web application. There is only one App Catalog site per web application
   • In Office 365/ SharePoint Online, the App catalog site is created at the tenancy level.

Types of SharePoint Add-ins

1. SharePoint hosted
2. Provider hosted

I’ll conclude here, in the next upcoming articles we will see more details, starting with the development of each type of Add-in, various development approaches for each type of Add-in, authentication and authorization for Add-ins, and so on.

References: SharePoint Add-ins