Better version detection

Hi, can I ask why Obtainium does not detect the version very well for apps that do not have a standard format?

This will cause some issues especially when it thinks that the app is updated but the same version was installed as mentioned in #941, can't it just extract the string from the system and compare it to the one indicated on the site?

I know I'm missing something so a brief explanation would be very helpful so I can understand the mechanism.

Thank you.

[ImranR98]

can't it just extract the string from the system and compare it to the one indicated on the site?

That's where the problem is - the string that comes from the system is the real version string, while the string that comes from GitHub is just the Git tag for that release (for other sources it is similar - a string extracted from somewhere that uniquely identifies a release but isn't necessarily the exact version string for that release). Most developers use version strings as Git tags which is great, but some don't. Some do, but add extra info to the Git tag.

For example, you could have any of these cases among others:

1. App version 0.14.21 but source says v0.14.21-beta (Obtainium)
2. App version 2.12.8-2+free but source says 2.12.8-2 (Cheogram)
3. App version 102.2.1-Release (12.5.6) (really, that whole thing is the OS-reported "version") but source says nothing - no version string is provided by this HTML source so a URL hash is used instead as the release identifier (Tor)
4. App version 1 but source says v10 (Quotable as described in this comment)

So there is no guarantee that the OS-provided "real" version will be in any way comparable to the source-provided "version" which really just needs to uniquely identify a release in order to enable update notifications - it doesn't need to be a real version string.

In most cases, where the strings seem to both conform to some standard format, like x.y.z or x.y, we can make the comparison - and this is when version detection is able to work. In some cases Obtainium can strip off extra parts from the source string if it would result in a standard version (like how v and -beta are removed from Obtainium's v0.14.21-beta), then it can make the comparison. We never try to strip parts off the "real" version, so in the case of Cheogram above, the versions could not be resolved to a standard format.

This is how the various "standard" versions are generated: https://github.com/ImranR98/Obtainium/blob/main/lib/providers/apps_provider.dart#L64
It's always possible to expand this to add more support but we'd need to be careful (see #136 where there was a lot of trial and error figuring this out). For example if an app reports 1.2 but the source says 1.2-4, should we strip off the number 4 and say the two are the same so no update? Right now, that wouldn't happen since we are only allowed to remove specific words and prefixes.

So in general if Obtainium can't resolve the differences between the two strings to a standard format, it disables version detection and hopes the user never has to update the app externally (in which case they would probably never notice the difference).

That's important to clarify - version detection is only relevant in 2 situations:

1. If an app's version changes outside of Obtainium (for example if it gets updated by Google Play)
2. If an attempt to silently update the app in the background fails

In those cases, version detection will allow Obtainium to detect that the app's real OS version has changed and update it's internal records accordingly, without generating a false update notification.

Note: For some sources, the source-provided string is guaranteed to be identical to the APK's real version string. For those sources, we skip all this version detection logic and just do a simple comparison. By default, all sources use the version detection logic, and "naive" version detection is enabled on a per-source basis (this means there may be some sources which don't use it right now, but could).

I'm not sure why you mentioned #941 though, I don't think version detection makes any difference there.

[ImranR98]

Feel free to re-open if needed.

I acknowledge the GitHub version detection problems that's why I change the version name for some apps that I compile with GitHub Actions, an example would be my fork of Signal, also KeePassDX when he adds "beta" attached directly to the number.

But this rule of removing some suffixes and prefixes can be skipped entirely and just compare the strings from the system and the sites as they are, because they keep the version name as it is in the app, not like apps from GitHub.

Examples:

APKPure	Aptoide	Uptodown

I hope you'll make some changes that will make Obtainium compare them direcly without any changes and keep your method only for specific sites like GitHub.

I hope you'll see this since I can't reopen the issue, but I will open a new one if I did not get a response.

[ImranR98]

Are you confident this is true for all APKPure, Aptoide, and Uptodown apps? It is for the ones I checked, just making sure.

[ImranR98]

Also I think I get how this relates to #941 now. Wouldn't fix the issue but would make sure the update would be retried later.