The framework provide the different View structs, which API match the SwiftUI framework guideline. If you're familiar with `Image`, you'll find it easy to use `WebImage` and `AnimatedImage`.
Since SDWebImageSwiftUI is built on top of SDWebImage, it provide both the out-of-box features as well as advanced powerful features you may want in real world Apps. Check our [Wiki](https://github.com/SDWebImage/SDWebImage/wiki/Advanced-Usage) when you need:
You can also get all benefits from the existing community around with SDWebImage. You can have massive image format support (GIF/APNG/WebP/HEIF/AVIF/SVG/PDF) via [Coder Plugins](https://github.com/SDWebImage/SDWebImage/wiki/Coder-Plugin-List), PhotoKit support via [SDWebImagePhotosPlugin](https://github.com/SDWebImage/SDWebImagePhotosPlugin), Firebase integration via [FirebaseUI](https://github.com/firebase/FirebaseUI-iOS), etc.
Besides all these features, we do optimization for SwiftUI, like Binding, View Modifier, using the same design pattern to become a good SwiftUI citizen.
This framework is under heavily development, it's recommended to use [the latest release](https://github.com/SDWebImage/SDWebImageSwiftUI/releases) as much as possible (including SDWebImage dependency).
This project use [keep a changelog](https://keepachangelog.com/en/1.0.0/) format to record the changes. Check the [CHANGELOG.md](https://github.com/SDWebImage/SDWebImageSwiftUI/blob/master/CHANGELOG.md) about the changes between versions. The changes will also be updated in Release page.
All issue reports, feature requests, contributions, and GitHub stars are welcomed. Hope for active feedback and promotion if you find this framework useful.
iOS 14(macOS 11) introduce the SwiftUI 2.0, which keep the most API compatible, but changes many internal behaviors, which breaks the SDWebImageSwiftUI's function.
Note: However, many differences behavior between iOS 13/14's is hard to fixup. Due to maintain issue, in the future release, we will drop the iOS 13 supports and always match SwiftUI 2.0's behavior.
For App integration, you should using Xcode 12 or higher, to add this package to your App target. To do this, check [Adding Package Dependencies to Your App](https://developer.apple.com/documentation/xcode/adding_package_dependencies_to_your_app?language=objc) about the step by step tutorial using Xcode.
For downstream framework author, you should create a `Package.swift` file into your git repo, then add the following line to mark your framework dependent our SDWebImageSwiftUI.
Note: This `WebImage` using `Image` for internal implementation, which is the best compatible for SwiftUI layout and animation system. But unlike SwiftUI's `Image` which does not support animated image or vector image, `WebImage` supports animated image as well (by defaults from v2.0.0).
However, The `WebImage` animation provide simple common use case, so it's still recommend to use `AnimatedImage` for advanced controls like progressive animation rendering, or vector image rendering.
Note: For indicator, you can custom your own as well. For example, iOS 14/watchOS 7 introduce the new `ProgressView`, which can replace our built-in `ProgressIndicator/ActivityIndicator` (where watchOS does not provide).
.scaledToFit() // Attention to call it on AnimatedImage, but not `some View` after View Modifier (Swift Protocol Extension method is static dispatched)
Note: `AnimatedImage` supports both image url or image data for animated image format. Which use the SDWebImage's [Animated ImageView](https://github.com/SDWebImage/SDWebImage/wiki/Advanced-Usage#animated-image-50) for internal implementation. Pay attention that since this base on UIKit/AppKit representable, some advanced SwiftUI layout and animation system may not work as expected. You may need UIKit/AppKit and Core Animation to modify the native view.
Note: `AnimatedImage` some methods like `.transition`, `.indicator` and `.aspectRatio` have the same naming as `SwiftUI.View` protocol methods. But the args receive the different type. This is because `AnimatedImage` supports to be used with UIKit/AppKit component and animation. If you find ambiguity, use full type declaration instead of the dot expression syntax.
Note: some of methods on `AnimatedImage` will return `some View`, a new Modified Content. You'll lose the type related modifier method. For this case, you can either reorder the method call, or use Native View in `.onViewUpdate` for rescue.
If you don't need animated image, prefer to use `WebImage` firstly. Which behaves the seamless as built-in SwiftUI View. If SwiftUI works, it works. If SwiftUI doesn't work, it either :)
If you need simple animated image, use `WebImage`. Which provide the basic animated image support. But it does not support progressive animation rendering, nor vector image, if you don't care about this.
If you need powerful animated image, `AnimatedImage` is the one to choose. Remember it supports static image as well, you don't need to check the format, just use as it. Also, some powerful feature like UIKit/AppKit tint color, vector image, symbol image configuration, tvOS layered image, only available in `AnimatedImage` but not currently in SwfitUI.
But, because `AnimatedImage` use `UIViewRepresentable` and driven by UIKit, currently there may be some small incompatible issues between UIKit and SwiftUI layout and animation system, or bugs related to SwiftUI itself. We try our best to match SwiftUI behavior, and provide the same API as `WebImage`, which make it easy to switch between these two types if needed.
The `ImageManager` is a class which conforms to Combine's [ObservableObject](https://developer.apple.com/documentation/combine/observableobject) protocol. Which is the core fetching data source of `WebImage` we provided.
For advanced use case, like loading image into the complicated View graph which you don't want to use `WebImage`. You can directly bind your own View type with the Manager.
It looks familiar like `SDWebImageManager`, but it's built for SwiftUI world, which provide the Source of Truth for loading images. You'd better use SwiftUI's `@ObservedObject` to bind each single manager instance for your View instance, which automatically update your View's body when image status changed.
This framework is based on SDWebImage, which supports advanced customization and configuration to meet different users' demand.
You can register multiple coder plugins for external image format. You can register multiple caches (different paths and config), multiple loaders (URLSession and Photos URLs). You can control the cache expiration date, size, download priority, etc. All in our [wiki](https://github.com/SDWebImage/SDWebImage/wiki/).
The best place to put these setup code for SwiftUI App, it's the `AppDelegate.swift`:
For more information, it's really recommended to check our demo, to learn detailed API usage. You can also have a check at the latest API documentation, for advanced usage.
SwiftUI's `Button` apply overlay to its content (except `Text`) by default, this is common mistake to write code like this, which cause strange behavior:
Instead, you must override the `.buttonStyle` to use the plain style, or the `.renderingMode` to use original mode. You can also use the `.onTapGesture` modifier for touch handling. See [How to disable the overlay color for images inside Button and NavigationLink](https://www.hackingwithswift.com/quick-start/swiftui/how-to-disable-the-overlay-color-for-images-inside-button-and-navigationlink)
SDWebImage itself, supports many custom loaders (like [Firebase Storage](https://github.com/firebase/FirebaseUI-iOS) and [PhotosKit](https://github.com/SDWebImage/SDWebImagePhotosPlugin)), caches (like [YYCache](https://github.com/SDWebImage/SDWebImageYYPlugin) and [PINCache](https://github.com/SDWebImage/SDWebImagePINPlugin)), and coders (like [WebP](https://github.com/SDWebImage/SDWebImageWebPCoder) and [AVIF](https://github.com/SDWebImage/SDWebImageAVIFCoder), even [Lottie](https://github.com/SDWebImage/SDWebImageLottieCoder)).
Here is the tutorial to setup these external components with SwiftUI environment.
##### Setup external SDKs
You can put the setup code inside your SwiftUI `App.init()` method.
@UIApplicationDelegateAdaptor(AppDelegate.self) var appDelegate
var body: some Scene {
WindowGroup {
ContentView()
}
}
}
```
##### Use external SDKs
For some of custom loaders, you need to create the `URL` struct with some special APIs, so that SDWebImage can retrieve the context from other SDKs, like:
+ FirebaseStorage
```swift
let storageRef: StorageReference
let storageURL = NSURL.sd_URL(with: storageRef) as URL?
// Or via convenience extension
let storageURL = storageRef.sd_URLRepresentation
```
+ PhotosKit
```swift
let asset: PHAsset
let photosURL = NSURL.sd_URL(with: asset) as URL?
// Or via convenience extension
let photosURL = asset.sd_URLRepresentation
```
For some of custom coders, you need to request the image with some options to control the behavior, like Vector Images SVG/PDF. Because SwiftUI.Image or WebImage does not supports vector graph at all.
SDWebImageSwiftUI supports to use when your App Target has a deployment target version less than iOS 13/macOS 10.15/tvOS 13/watchOS 6. Which will weak linking of SwiftUI(Combine) to allows writing code with available check at runtime.
Add `-weak_framework SwiftUI -weak_framework Combine` in your App Target's `Other Linker Flags` build setting. You can also do this using Xcode's `Optional Framework` checkbox, there have the same effect.
You should notice that all the third party SwiftUI frameworks should have this build setting as well, not only just SDWebImageSwiftUI. Or when running on iOS 12 device, it will trigger the runtime dyld error on startup.
For deployment target version below iOS 12.2 (The first version which Swift 5 Runtime bundled in iOS system), you have to change the min deployment target version of SDWebImageSwiftUI. This may take some side effect on compiler's optimization and trigger massive warnings for some frameworks.
However, for iOS 12.2+, you can still keep the min deployment target version to iOS 13, no extra warnings or performance slow down for iOS 13 client.
Because Swift use the min deployment target version to detect whether to link the App bundled Swift runtime, or the System built-in one (`/usr/lib/swift/libswiftCore.dylib`).
+ For CocoaPods user, you can change the min deployment target version in the Podfile via post installer:
```ruby
post_install do |installer|
installer.pods_project.targets.each do |target|
target.build_configurations.each do |config|
config.build_settings['IPHONEOS_DEPLOYMENT_TARGET'] = '11.0' # version you need
end
end
end
```
+ For Carthage user, you can use `carthage update --no-build` to download the dependency, then change the Xcode Project's deployment target version and build the binary framework.
+ For SwiftPM user, you have to use the local dependency (with the Git submodule) to change the deployment target version.
##### Backward deployment on iOS 12.2+
+ For Carthage user, the built binary framework will use [Library Evolution](https://swift.org/blog/abi-stability-and-more/) to support for backward deployment.
+ For CocoaPods user, you can skip the platform version validation in Podfile with:
+ For SwiftPM user, SwiftPM does not support weak linking nor Library Evolution, so it can not deployment to iOS 12+ user without changing the min deployment target.
+ [ViewInspector](https://github.com/nalexn/ViewInspector): Inspect View's runtime attribute value (like `.frame` modifier, `.image` value). We use this to test `AnimatedImage` and `WebImage`. It also allows the inspect to native UIView/NSView, which we use to test `ActivityIndicator` and `ProgressIndicator`.
1. Run `carthage build` on root directory to install the dependency.
2. Open `SDWebImageSwiftUI.xcodeproj`, wait for SwiftPM finishing downloading the test dependency.
3. Choose `SDWebImageSwiftUITests` scheme and start testing.
We've already setup the CI pipeline, each PR will run the test case and upload the test report to [codecov](https://codecov.io/gh/SDWebImage/SDWebImageSwiftUI).
