How Progressive Web Apps and Nucleus Combine to Make SharePoint Content More Accessible

Make Web Sites into Apps

I confess to have been a little underwhelmed by Microsoft’s June 11 announcements (MC261535 and MC261537) that it will soon be possible to install OneDrive for Business and Microsoft Lists as Progressive Web Apps (PWAs). The relevant Microsoft 365 roadmap items are 80240 (OneDrive) and 80241 (Lists).

I should explain that I’m not so impressed as others might be because I’ve been installing various Office 365 web pages as apps in Edge for months (any Chromium-based browser works, Safari doesn’t). OWA works well as an app. The basic idea is that you use the Apps option in the browser to install a site as an app. Figure 1 shows what happens when you install OneDrive for Business as an app.

Making OneDrive for Business into an app using Microsoft Edge
Figure 1: Making OneDrive for Business into an app using Microsoft Edge

The only other thing to do is to name the app (Figure 2).

Naming a PWA
Figure 2: Naming a PWA

The web pages installed as apps show up in the Windows start menu (Figure 3) and can be pinned to the taskbar.

Web apps listed in the Windows start menu
Figure 3: Web apps listed in the Windows start menu

All About Access

The big advantage gained by installing web pages as apps is access. For instance, given the number of SharePoint sites in use today (many created by Teams), it’s often convenient to have an app pointing to a document library you use frequently. When an app starts, it has its own window. However, the functionality of the web page works in an app exactly like it does when it runs in a browser tab. As I said, it’s all about access, or rather, making information you use frequently more accessible.

If you can make Office 365 web pages into apps today, what’s Microsoft doing in MC261535 and MC261537? I think a couple of reasons exist:

  • Make people aware that they can access OneDrive for Business and Lists as apps.
  • Tune the pages so that they work well as PWAs.

Project Nucleus Arrives

Nice as it is to make OneDrive and Lists into apps, I’m much more impressed by the news in MC261538, which covers the introduction of a new general-purpose synchronization engine to the OneDrive sync client (Microsoft 365 roadmap item 68809).

Microsoft discussed Project Nucleus at the Ignite 2020 conference and said that they would use it to make Lists available offline (Figure 4). That’s what is being delivered with roll-out beginning in early July and due for completion in early August. Initially, Nucleus is only available for Windows 10 workstations.

Project Nucleus (source: Microsoft)
Figure 4: Project Nucleus (source: Microsoft)

A separate Microsoft Nucleus.exe runs to synchronize Lists. According to Microsoft, “the sync process begins when a user first navigates to any list or to the Lists web app. All eligible lists that are visible from the Lists app will be synced. Common operations on lists, such as changing list views, sorting, filtering, and grouping happen locally and finish quickly even on very large lists. All of these operations continue to work offline. Edits sync between your device and the cloud and you can resolve merge conflicts if there are any.”

Microsoft has done a lot of work over the years to improve the OneDrive sync client by adding features like differential synchronization to make it capable of dealing with large files. Nucleus takes on the job of dealing with the synchronization of large and complex datasets, apparently using SQL Lite as a metadata store to allow users to continue working during network outages or when the network connection is flaky. Microsoft says that “requests are handled through a secure localhost HTTP server” and that complete documentation covering the management of Nucleus is on the way.

Two Sides of the Same Coin

PWAs and Nucleus are linked in the grand plan to make ODSP information more accessible. Web sites installed as apps need offline capability and Nucleus provides this ability for OneDrive for Business and SharePoint (ODSP) apps in the same way as other local stores deliver for apps like OWA and Teams.


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