Canvas Power App SignalR PCF

[cssrt123]

Hi there, hoping someone here will be able to point me in the right direction.

Been using Power Apps for a while now, and have started playing about with a PCF to use SignalR after watching a couple of youtube videos and thinking it would be great it have in an app.

Have managed to setup, install and incorporate in an app.....and have it sending messages, and images, between browser instances. But I cannot get the mobile version to do anything.....and with it being mobile and Power App android app, there's no Inspect option to see the console and see what's going wrong.....

Been searching frantically, adding every URL I can find into CORS.....but just can't get the mobile version to work. 

Has anyone got a canvas app, that works on a mobile, and can send messages via SignalR? What am I missing?

Chris

[cchannon]

Does it not work on mobile devices at all, or does it work on mobile Web, but not mobile App?

[cssrt123]

@cchannon It works on a browser on mobile, but just not in the Power Apps app; and the browser on mobile isn't a great user experience, so the app has to connect somehow.

[cchannon]

OK, then what you've got here is an issue in the host app, right? I mean, keep in mind that SingalR pages are doing a very unusual thing: creating a session with a server independent of the page context that can arbitrarily receive inputs without polling. In that light, it isn't surprising that a mobile app wouldn't play nicely.

If your users only have a couple of Power Apps on mobile 🤞, then I would look at having them install as PWAs instead of using the Power Apps interface. That parent interface is pretty clunky anyway and carries all that pink/purple branding that users find very distracting. By moving to PWA, you'll be returning to a browser context and your SignalR code should work, plus you'll clean up the user experience by having your users click an icon and get to the app - with no app library nonsense shoved in the middle.

Otherwise, if keeping the Power Apps app is a MUST, then I would reconsider your SignalR approach and try to leverage in-app notifications maybe? Pretty disappointing, I know, but I doubt you're going to find a way to 'fix' the MSFT app.

[cssrt123]

@cchannon There definitely something about the host app, and without the option to inspect the console, it's difficult to know what's (presumably) blocking it. 

The issue with getting rid of Power Apps is that we have quite a lot of them. You are right, the host app isn't the best, and with so many different levels of users, some are fine, and others struggle to find/load apps.

The thing is, I know it should be possible - Rui Santos LinkedIn post/video of SignalR / PCF on mobile , so I should have to move away from Power Apps, or move away from SignalR. Power Apps notifications just won't do the job, as it's not just a popup message that's being sent but also an in-app command to connected users to update a specific record, to save on regularly polling the main dataset. There are a few demos out there of how to make the PCF and the app, but just nothing the specifically touches on what's different about making it work via the host app.

[cchannon]

Yeah, that's why I was hoping you only have a couple of them. Replacing the Power Apps app with PWAs en masse would be very challenging.

Is the capability isolated? As in, only happening in one spot on one form? If the scope is very limited, you could just implement a PCF that polls for updates every few seconds. It would be unnecessarily chatty and on mobile devices your users might notice a bit of slowdown, but if there aren't a ton of places where you're doing it, this kind of brute force approach could definitely work.

[cchannon]

Also, even though it may be too late to change things for your existing users/apps, I suggest you consider PWAs for future app rollouts... They are simply cleaner to work with from a user perspective 90% of the time.

[cssrt123]

@cchannon Currently, the app's a proof of concept idea, as we're trying to make something in-house to replace an external system we pay for, and SignalR would tick two boxes - a "chat" feed of messages, but also a "system" feed of updates, designed not to appear anywhere like a chat message, but to trigger a refresh of that line of data from a DV table, to save a timer/poll scenario when there will be hundreds rows per day in the table. So, to answer the question....it's very isolated currently, as it's only in a test app and it's really only being used to try and send/receive a test message as a chat; just trying to get it to work reliably between mobile/desktop before it get built a bit more.

[cchannon]

Yeah, that's a tough spot. Chat won't work with polling. It needs real-time responses...

That said, a chat experience also needs screen real estate, so on mobile it's going to eat up the screen anyway... Why not host your chat in a web resource (or in azure) then just put a "click to open chat" button in your power app? 

That would push your chat back into browser where you can use signalR, and in the app you can just poll every 10 (20?) seconds to find out if you need to refresh screen.

[cssrt123]

@cchannon The app/process we're trying to create a proof of concept for has a chat feed built in, and users don't like change as it is....so for the POC we're trying to make it function as close as we can to current. However, going forward, it would become what's needed, not what they want.

However, I'm aware that the chat takes up space, and I'd be planning on hiding it when not in use, make it appear in a popup and let you know there are new messages etc. Plus if I start moving users out of the PA experiences, and into a browser, and then expect them to get back to the app to use it too, it becomes more complex a user experience - especially considering there are a lot of different user abilities involved. 

However, as I mentioned this is currently just a proof of concept basic test, and i'm trying a basic chat just to get it functioning on a mobile (in the app) and in on a PC (via browser). The real use case will have a database of entries, possibly 200+ per day, which is why I don't want to be constantly polling the db for updates without knowing what's changed - my intention is to use SignalR to send a command, and when it receives the trigger (an ID number for example) it knows to revert that row only, rather than all 300 for possibly nothing. The chat feature would be secondary to this.