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Discover how to ensure that changes made in the detail view of your SwiftUI app effectively update the previous views, using `@ EnvironmentObject` for state management.
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This video is based on the question https://stackoverflow.com/q/68644104/ asked by the user 'graem' ( https://stackoverflow.com/u/12817063/ ) and on the answer https://stackoverflow.com/a/68645687/ provided by the user 'Kristo Kiis' ( https://stackoverflow.com/u/983601/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

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How to Properly Update Views After Saving Changes in SwiftUI with @ EnvironmentObject

In SwiftUI, managing the flow of data between views can sometimes be challenging, especially when users interact with multiple views to edit data. If you're developing an app where users can input and save stock trades, for instance, you might encounter issues where updates made in a detail view don't reflect in the corresponding list view upon saving. This post addresses that problem and provides an effective solution.

The Problem: Changes Not Reflected

You might have implemented a stock trading application where users can enter their trades and later view statistics in a list format. When navigating from this list view to a detail edit view and saving changes, the list view does not get updated—and that can be frustrating, both for you as the developer and for your users.

Here’s a glimpse of the code in your List View and Edit View:

List View

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Edit View

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The above implementation does not account for shared state between the views, which is crucial for ensuring that updates reflect across the app.

The Solution: Using @ EnvironmentObject

To resolve the issue of your previous view not being notified of changes, a robust solution is to create a centralized database instance and leverage @ EnvironmentObject to share it across your views.

Step 1: Create a Mock Database

Start by creating a mock database class that conforms to ObservableObject. This allows your data to be shared and updated across views seamlessly.

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Step 2: Implement @ StateObject in Your Stock View

In your list view, initialize your mock database as a @ StateObject and pass it down as an environment object. This effectively keeps the data synchronized across views.

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Step 3: Use @ EnvironmentObject in Your Edit View

In your edit view, consume the environment object. This allows the view to access the shared mock database and ensures any changes made during the edit are reflected back in the list view.

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Conclusion

By utilizing the @ EnvironmentObject in your SwiftUI application, you're establishing a shared state that allows different views to react to and display updates as they happen. This approach provides a more organized and effective way to manage your app's data, leading to a smoother user experience. If you're continually wrestling with data flow in SwiftUI, adopting this pattern can save you a significant amount of hassle.

Make sure to implement these changes in your project and watch as your views update seamlessly, providing an improved experience for your users. Happy coding!