Canvas app code in Power apps portal

[umnex]

Hi,

We are building an access request app in which employees can submit office visit requests during lock downs. We have successfully built a canvas app for employees in which they are able to select visit date and app suggests available visit slots to them.

Now we want to build the same functionality for external visitors and for that we have chosen Powerapps portals since it supports anonymous users. Now we are stuck because power apps portals have a totally different architecture than power apps. We are unsure how and where to implement the logic for generating visit time slots that visitor can select. For canvas app all of our data is being stored in SharePoint Lists. My questions are:

• Is there a way to directly access SharePoint Lists as data source for power apps portal?
• How can we implement the logic of generating time slots (time slots must be within start and end time and should not allow booking if anyone else has previously booked the slot).

Any help and guidance is truly appreciated. Thanks.

[OliverRodrigues · Accepted solution]

Hi, design/architectural decisions are always tricky and it's very difficult to plan ahead.

If you need external access, Portals can be a great option, but Portals relies very much on Dataverse (CDS/D365), you don't need to worry about having a full D365 in place, but you need to know that the Portals architecture depends on it.

Anyways, answering to your questions:

• Portals cannot access directly a SharePoint list.. there is an integration with SharePoint but this would be more for uploading files against a record in Dataverse
  • You are better off mapping your SharePoint list data model to Dataverse
• Generate time slots: 
  • Any business logic can be implemented via client-side (Portals / JS), or server-side (Dataverse plug-ins using c#) or using Power Automate Flows

All those should be possible, but I can't say you would leverage any existing Canvas App code.. unless you want to keep Canvas for internal users, and use Portals for external.. either way you should centralize everything into a single database (Dataverse would probably be the best option)