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View models in MVVM are responsible of making the model suitable for presenting by a view. Quite often model objects themselves have properties which can be directly presented by the view. SE-0195 added dynamic member lookup types. Using @dynamicMemberLookup we can add all the model object's properties to the view model itself. Result, model.name is …
Everything can't go exactly as planned and therefore, at some point, there is a need for presenting localized error messages to the user. Let's take a look at how to add custom error type what provides error description, failure reason and recovery suggestion and presenting it in SwiftUI view. Adding custom error type Custom error …
Apps which integrate push or local notifications can customise notifications on Apple Watch. Let's go through steps required for adding dynamic notifications on Apple Watch. Sample use case is an app which reminds when a plant needs watering. We'll only concentrate on adding dynamic notification view and leave out sending local notifications from the iOS …
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CoreData is Apple's object graph and persistence framework. It provides data sources for synchronising data with view. Let's take a look on how to use those data sources in SwiftUI views. Starting with NSFetchedResultsController what is used for list and collection views, after that observing NSManagedObject directly from SwiftUI view and lastly subscribing to managed …
Let's build a simple app using MVVM (model-view-view model) where every SwiftUI view has its own view model. It's going to be an app with two views: list of movies and add a movie view what utilises Form view. Added movies are stored in MovieStore which is shared by the two view models. We will …
One building block for navigating from one view to another is NavigationView which is a representation of UINavigationController in UIKit. This time, let's take a look on how to transition from one SwiftUI view to another one without NavigationView. AppFlowCoordinator managing choosing the view The idea is to have a root SwiftUI view with only …
Instead of initializing SwiftUI views with dependencies, SwiftUI also offers other ways for injecting dependencies. This time let's take a look on EnvironmentKey which defines a key for inserting objects to environment and vise-versa. We need to create a EnvironmentKey, adding an object to environment and then getting the object in SwiftUI view. Creating EnvironmentKey …
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This year Apple added CGAnimateImageAtURLWithBlock and CGAnimateImageDataWithBlock for animating GIFs and APNGs on all the platforms to the ImageIO framework. We can pass in URL or data and get callbacks when animation changes the current frame. In Xcode 11 beta 7 implicit bridging to Swift is disabled for those APIs and therefore we need to …
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Apple's Vision framework contains computer vision related functionality and with iOS 13 it can detect text on images as well. Moreover, Apple added a new framework VisionKit what makes it easy to integrate document scanning functionality. For demonstrating the usage of it, let's build a simple UI what can present the scanner and display scanned …
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Let's build a conversation view which shows a list of messages and has input text field with send button. Sent and received messages are managed by Conversation object. Conversation object manages a Session object which is simulating networking stack. This kind of setup allows us to look into how to propagate received messages from Session …
Continue reading "Creating chat view with Combine and SwiftUI"
