How to Run a Flow and Use Its Result in Power Apps

FlowName.Run() runs a flow from a canvas app and returns what the flow sent back, with each output as a field. Call it in a button's OnSelect, keep the result in a variable for the screen to show, and select that button from the screen's OnVisible so the data loads when the screen opens.

The example is the Waiting for Approval screen of the Overtime Timesheet app. Its Refresh button runs Get Waiting Approvals, which returns the overtime entries waiting for the approver as JSON text in an output named entries.

Prerequisites

• The flow added to the app (How to Add a Flow to a Canvas App in Power Apps).
• A button to run it. Here, a Refresh button in the screen's header (How to Add a Refresh Button to a Screen in Power Apps).

Step 1: Run the Flow in a Button's OnSelect

Run() belongs in a property that runs when something happens, such as a button's OnSelect. Microsoft's Power Automate pane article uses the same place. The output is a field of the result:

The flow's output

GetWaitingApprovals.Run().entries

Step 2: Keep the Result in a Variable

A screen's labels and gallery can't call a flow themselves, so the button stores what the flow returned in context variables (How to Use Context Variables in Power Apps with UpdateContext). The complete OnSelect:

btnRefreshWA → OnSelect

UpdateContext({ locIsLoadingWA: true });
With(
    { response: IfError(GetWaitingApprovals.Run(), Blank()) },
    If(
        IsBlank(response),
        UpdateContext({ locLoadFailedWA: true });
        Notify("The entries waiting for you couldn't be loaded. Select Refresh to try again.", NotificationType.Error),
        UpdateContext({
            locLoadFailedWA: false,
            locEntriesWA: ForAll(
                ParseJSON(response.entries),
                {
                    ID: Value(ThisRecord.id),
                    Employee: Text(ThisRecord.employee),
                    Department: Text(ThisRecord.department),
                    StartTime: DateTimeValue(ThisRecord.startTime),
                    EndTime: DateTimeValue(ThisRecord.endTime),
                    BreakMinutes: Value(ThisRecord.breakMinutes),
                    SavedOn: DateTimeValue(ThisRecord.savedOn)
                }
            )
        })
    )
);
UpdateContext({ locIsLoadingWA: false })

What each part does:

• locIsLoadingWA is true while the flow runs. A loading spinner shows while it's true (How to Add a Loading Spinner in Power Apps).
• With runs the flow once and keeps the result in response (How to Use the With Function in Power Apps).
• IfError(..., Blank()) turns a failed call into a blank, so the formula can say so itself (How to Handle a Failed Flow Call in Power Apps).
• ParseJSON and ForAll turn the JSON text into a table with proper types (How to Turn JSON Text into a Table with ParseJSON in Power Apps).
• locEntriesWA holds the table, and the gallery's Items is locEntriesWA.

Step 3: Load It When the Screen Opens

In the screen's OnVisible, select the button, so opening the screen runs the same formula (How to Use the Select Function in Power Apps):

Waiting for Approval Screen → OnVisible

Select(btnRefreshWA)

One formula then serves both cases: opening the screen and selecting Refresh.

The Result

For an approver with one entry waiting, the screen showed it after the flow answered:

In Studio, selecting the screen in the tree ran its OnVisible, so the flow ran there too, under the maker's account.

Common Mistakes

Mistake	What happens	Do this instead
Run() in a gallery's Items	Behavior function in a non-behavior property	Run it in OnSelect, store the result
Calling Run() twice in one formula	The flow runs twice	With keeps one result
IfError around UpdateContext	It doesn't catch the failure	IfError around Run() (the fix)
No loading indicator	The screen looks stuck while the flow runs	A spinner on a loading variable

Troubleshooting

Symptom	Likely cause	Fix
.entries isn't offered after Run()	The app has the flow's old definition	Refresh the flow in the app
Works for you, fails for others	The flow isn't shared with them	How to Share a Flow with Run-Only Users in Power Automate
The screen stays empty	The flow returned nothing, or the call failed	Check the flow's run history

FAQ

Does the app wait for the flow?

Yes. The formula continues once the flow has responded, which must happen within 120 seconds (How to Send Values Back to Power Apps from a Flow in Power Automate).

Can I pass values to the flow?

Yes, if the flow's trigger has inputs: they go inside the brackets, in order, such as MyFlow.Run("value"). Microsoft warns that those values can be seen as network traffic, so the flow should check them. This flow takes none: it works out who's calling by itself.

Conclusion

Run the flow with FlowName.Run() in a button's OnSelect, keep its result in a variable with a loading flag around the call, and select the button from OnVisible. The screen then shows the flow's answer whenever it opens or the user refreshes it.

Additional Resources

• Use Power Automate pane: reference a flow

Related

• How to Add a Flow to a Canvas App in Power Apps
• How to Turn JSON Text into a Table with ParseJSON in Power Apps
• How to Handle a Failed Flow Call in Power Apps
• How to Run a Formula When a Screen Opens in Power Apps (OnVisible)