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Ultimate Portfolio App - View Modifier for Previews idea

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@cgaaf  

So I've started Paul's new Ultimate Portfolio App series.

Really enjoying the series so far. After finishing the "First steps in UI" article I realized that copying the code to add the DataController and CoreData each time would become repetative and cumbersome.

To make working with Previews a little more "DRY," I created a custom view modifier to add all of the DataController code. So far this seems to be working effectively. Let me know what you all think.

struct PreviewDataInjector: ViewModifier {
    let dataController = DataController.preview

    func body(content: Content) -> some View {
        content
            .environment(\.managedObjectContext, dataController.container.viewContext)
            .environmentObject(dataController)
    }
}

extension View {
    func previewDataController() -> some View {
        self.modifier(PreviewDataInjector())
    }
}

Then you can just use the view modifier to eliminate the boiler plate on previews.

struct ProjectsView_Previews: PreviewProvider {
    static var previews: some View {
        ProjectsView(showClosedProjects: false)
            .previewDataController()
    }
}

1      

Nice but you will need to add

#if DEBUG
...
#endif

around the struct and extension as Previews are only on Debug not Release

2      

@cgaaf  

Great point!

1      

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