After calling deleteAll() and creating a new dataset, old data is still visible in the ProjectsView. At least for me! Is this expected, is the View holding on to some cached data?

Same question here. Hitting "add" several time should to my understanding delete all projects/ items and create 5 new projects. However old data keeps staying.

Could you kindly let me know what you edited exactly on the Button?

I tested to add a new button doing only the delete, and it worked fine. Then I undid my edit, back to the original, and it still worked. I really can't figure out what happened. 🤷

Looks like we need a call to dataController.save() in HomeView after the call to dataController.deleteAll(). Look at this tweet.

https://twitter.com/MrGLWatson/status/1320448229914353666

Well done @TwoFortyTwoApps

Here

Button("Add Data") {
    dataController.deleteAll()
    dataController.save()
    try? dataController.createSampleData()
}

This is still not updating until I restart the app even after doing

Button("Add Data") {
    dataController.deleteAll()
    dataController.save()
    try? dataController.createSampleData()
}

For anyone still having this issue, I found another solution here that worked: https://www.hackingwithswift.com/forums/plus/ultimate-portfolio-app-homeview-not-updating-after-datacontroller-deleteall/8318/11692

Actually Usful Url For Datacontroller Issue - https://www.hackingwithswift.com/forums/plus/ultimate-portfolio-app-homeview-not-updating-after-datacontroller-deleteall/8318/11692