Are Universl Apps truly universal?

[runamuck83]

We don't have Windows 10 Mobile officially released yet - but I've noticed on a few occasions where the "mobile" app will be updated while the "desktop" app will not and vice versa.

I thought these universal apps were the SAME app? How/why are they updated separately?

 

[milkyway]

I'm not a developer but my understanding is this: A UAP (e.g. MS weather app) uses the same baseline but a different UI and/or customizations for every device. You write your code and when it comes to compiling you have to choose for which device you want to compile you UAP. If you don't have anything new in your code that's relevant for the W10 mobile you maybe just want to compile it for W10 desktop.

Please someone correct me if I'm wrong

 

[xandros9]

Some of them are, not necessarily all of them.

 

[a5cent]

I'm not a developer but my understanding is this: A UAP (e.g. MS weather app) uses the same baseline but a different UI and/or customizations for every device. You write your code and when it comes to compiling you have to choose for which device you want to compile you UAP. If you don't have anything new in your code that's relevant for the W10 mobile you maybe just want to compile it for W10 desktop.

Please someone correct me if I'm wrong

No. That's how it worked on WP8.1. Now you have one app that you only compile once. That single app can decide at runtime which UI configuration to use to create the app's UI.

However, this ability existing doesn't mean developers must use it. MS defines a universal app as any app that runs on the UAP, but that doesn't guarantee the app will run on more than one form factor. A developer can still limit an app to running on just one form factor, e.g. if the developer has no interest in designing multiple UI confugurations.

 

[Daniel Rubino]

I'm not a developer but my understanding is this: A UAP (e.g. MS weather app) uses the same baseline but a different UI and/or customizations for every device. You write your code and when it comes to compiling you have to choose for which device you want to compile you UAP. If you don't have anything new in your code that's relevant for the W10 mobile you maybe just want to compile it for W10 desktop.

This is correct.

Also, some companies are holding back on Windows 10 Mobile because it's a beta OS. There's not much point in releasing an app on buggy software, especially when it is such a little audience.

 

[a5cent]

^ As long as the developer isn't targeting a particular CPU architecture, the part about compilation is incorrect.

Thanks to the extensibility of the UAP, you can include device-specific code in a single binary that will run on every device.

source on MSDN

Compilation is what results in the executable binary file. Ending up with a single binary means you compile once. If we have only one binary executable that runs on multiple form factors, then the OP is correct to assume that updating a universal app in the store, should update that app for all form factors simultaneously, not individually like the OP has observed.

 

[a5cent]

Saying that some companies are holding back on W10M is certainly true, but I don't think it answers the question as to why universal apps appear to be updated individually by form factor. A few examples:

1)
Testing may be one reason. If you fixed a critical bug that only rears its head on smartphones, and you want to deploy the fix quickly, it may be worthwhile to make that release available only to phones until you've had time to fully test it for tablets and other form factors.

2)
A less dramatic and very common scenario is when a universal app makes use of existing software components which themselves aren't universal. An app that uses one library which exists in two versions, one for ARM devices and the other for x86 devices, is a very common example. Any app that uses such libraries, even if it is a universal app, must be packaged up twice, once for each CPU instruction architecture.

3)
Another example would be that of a universal app that is not a W10 universal app, but a W8.1 universal app, where things work differently (the way milkyway described). In this case the only thing that is truly universal is the app's identity in the store, whereas the binary files that are distributed to devices vary depending on the device doing the downloading. Both types of apps are called universal apps, despite not technically being the same thing.

I'm sure there are many more scenarios where a universal app wouldn't strictly behave like one (as described by the OP).

 

[someone2639]

I think it's just the C++ libraries on each device interpreting the apps differently.

 

[a5cent]

^ Yeah, that's the second reason I mentioned above, but there's no way that's the only possible reason. There are just way too many factors that could cause a company to manage desktop/phone releases separately.

 

[Zachary Boddy]

Enjoyable thread. I don't have anything to add it's all been said already.

 

[a5cent]

^ May I say that your reason for editing made it that much more enjoyable? :wink:

 

[Zachary Boddy]

^ May I say that your reason for editing made it that much more enjoyable? :wink:

If you'll look at most of the posts where I edited they're all sarcastic comments. I can't be bothered to take my mistakes seriously, haha.

 

[Krystianpants]

Most of these apps in the store are 8.1 universal. They don't even sync settings between each other. Games require logging into facebook, etc..

Now Candy crush is apparently universal but once again unless you login to facebook you don't sync any information. So I find that weird since the purpose of universal is to have the same app running on all systems and includes continuity. Yah if you have a facebook account.... hehe

It's likely apps are being fubared because of the 2 stores that are being maintained. The new store is just going to be a nightmare with mix of 8.1 and 10 apps. And i believe anyone can continue publishing 8.1 universal apps to the new store. And by the time 10 is released and everyone is moved over, there will be more 8.1 apps than anything and of course Windows 10 as one service won't really even make sense given that you need to download separate apps and maintain them separately on each device. Microsoft will once again get a bad rep.