Microsoft Power Apps Canvas Apps, Power Fx Formulas, and Controls
View All Tags
The '.' operator cannot be used on Error values means the name on the left of a dot has already failed, so Power Apps can't read a field from it. In my case, a copied control brought along a context variable that only exists on another screen. The fix is on the left of the dot.
Until now, only the person building the app has used it. This part publishes it, shares it with the team, and opens it as a team member who has nothing but a Microsoft 365 license. Then it builds the manager's side: a My team screen with each direct report, and a screen per person showing what's waiting for review and where their plan stands.
Power Fx has no Exists function, but you don't need one: LookUp returns the first record that matches, or blank when nothing does. Wrap it in !IsBlank(...) and you get true when a record exists. On SharePoint, it's delegable.
Live monitor records what a canvas app does while it runs: which button was selected, which data it fetched, how long that took, and warnings such as delegation. When a formula gives an unexpected result, it shows what really happened.
The first time someone opens a canvas app shared with them, Power Apps asks: Allow [the app] to access your data? The app uses their own SharePoint and Microsoft 365 connections, so each person agrees once. This guide shows the dialog and what it means.
Power Apps works out a License designation for every app from what it connects to. Standard apps run with the Power Apps rights included in many Microsoft 365 licenses; Premium apps need a Power Apps plan. It takes a few seconds to check.
A canvas app's web link opens it straight in a browser. You need it to tell people about an app you've shared, because sharing doesn't always notify them. There are two places to get it.
Sharing a canvas app with a security group lets every member run it, and anyone added to the group later gets the app without another share. This guide shares an app in the new Share dialog and covers two things it doesn't do: give access to your data, and tell people.
Saving a canvas app keeps your changes; publishing gives them to the people you've shared the app with. Until you publish, they keep using the previous version, or can't open the app at all if it was never published.
You publish a new version of a canvas app, and a user who has it open still sees the old one. In the example, no update notice appeared, and even the first reload, a few minutes later, still opened the previous version. Reloading again a few minutes after that loaded the new screens.
