KFImage does not being displayed in some cases after 6.2.1

[ramluro1]

Issue Description

Images not being displayed after pod update to 6.2.1. in SwiftUI app

What

Works fine after I reverted back to 6.1.1

Reproduce

[The steps to reproduce this issue. What is the url you were trying to load, where did you put your code, etc.]

Other Comment

[Add anything else here]

[onevcat]

Hi,

Maybe you can try to call loadImmediately() after you set up the KFImage to see if it works. Like this:

KFImage.url(url)
    .resizable()
    .onSuccess { r in print("done") }
    .loadImmediately() // Add this after the last chained call for `KFImage`
    .frame(height: 100) // Other `SwiftUI.View` modifiers

In 6.1, we tried a new implementation which "keeps" the image state between KFImage creation, but it caused other problems. So we are now back to the implementation of 6.0. The root cause is that @ObservedObject does not keep itself between views lifetime. @StateObject in iOS 14 is the tool to solve it. However, since we still need to support iOS 13, we cannot use that yet.

loadImmediately() will trigger a load as soon as you configured the KFImage, instead of lazily load it until onAppear is called (which will never happen sometimes when you change something and trigger a re-evaluating of body).

[ivasic]

Not the OP but I have the exact same problem and indeed, adding loadImmediately() fixes it.

@onevcat is this the recommended usage or just a temporary workaround?

[onevcat]

It is the recommended usage until we can drop iOS 13 support (Maybe later this year when iOS 15 comes out!)

[netbe]

@onevcat Do you plan to do an availability check to use StateObject ? or at least add a warning on Readme ?

[onevcat]

@netbe It is hard to choose it with an availability check, which does not support a type member. The plan is switching to @StateObject when the new version of iOS 15 announced (WWDC). So we can try to adapt to some new features and drop iOS 13.

[wilg]

We are encountering this as well, it feels pretty broken. Maybe .loadImmediately() should be the default?

[onevcat]

@wilg It once was, but in a recent syntax improvement for a chain-able configuration, there is no way to call it unexplicitly. Furthermore, an image loading every time when the layout changed is also not a desired behavior.

A patch for switching to @StateObject is already in #1707 and the feature/StateObject branch. If you only use SwiftUI for iOS 14, it worths to try and keep using that until the next major release of Kingfisher.

[wilg]

OK, I'll try that. I guess my thinking is that this is such a serious bug that Kingfisher is essentially unusable in SwiftUI without it, so it might be worth doing something drastic.

It took us a long time to figure out that this was a Kingfisher issue, and we shipped some bad releases until we figured it out today.

[onevcat]

@wilg Oh! I am very sorry to hear that.

I really hope we can solve it by dropping the broken @ObservedObject soon!

[onevcat]

The @StateObject based image binder is now in master. It requires the deploy target upgrade to iOS 14. I am going to prepare a release for it soon.

[onevcat]

This is already fixed in version 7 (currently in beta). The loadImmediately() is not necessary anymore in the new release (but the method itself will be left there for a while without doing anything, for backward compatibility). The new major upgrade version Kingfisher 7 requires iOS 14 for using KFImage. Please remember to check the migration guide before you decide an upgrade.

There are still some other features in plan & waiting fixes from Apple's Xcode 13 betas. Kingfisher v7 won't be officially released before there is a GM version of new iOS 15 and Xcode 13.

[Anton-Trubianov]

I still facing the same issue KF v7, i roll back to v6.3.1 and added loadImmediately only this setup fixing issue in 99%, in my app is list with paging that loads data async way 20 item per page, and even this setup some but occurs but not often 1-5% if scrolling is fast, wifi or LTE it doesn't matter.
IOS 16.2
Xcode Version 14.2 (14C18)
SwiftUI
Using KF with SPM

[onevcat]

For issues with iOS 16 (before iOS 16.4), I believe it was another issue mentioned in #1988

Please check there for the detail and some possible workaround. This issue should not happen when building with Xcode 14.3 and for deploy targets later than iOS 16.4.