SwiftUI previews in a Tuist-generated project

[marekfort]

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@Stanly_Shiyanovskiy: Hi folks!
May be I misunderstood but is it possible to make standalone project and use there SwiftUI previews?

My problem: I have old UIKit project, I want to make separate module with new SUI views that I will be start to use in my main project.

Thanks in advance.

@Marek_Fořt: Yes, you can use SwiftUI previews in a project – not sure exactly what you mean by “standalone”. Would you mind expanding a bit on your use case?

There’s plenty of fixtures here that you mind find interesting

@Stanly_Shiyanovskiy: I have a static library as a Project SharedViews where added all my SwiftUI views. MainApp imports that library and use views in the app. Also I want to create PreviewModule where will be stored all previews of the view files to make UI layout quickly. So it should be like:

MainApp
|
|— SharedViews (static library)
| |
| … some SwiftUI files here
| |
| — PreviewModule (dynamic library)
| |
| … #Previews files here
| |

I found many projects from fixtures but nothing helps me. Maybe I misunderstood something?

1. My MainApp should import only staticLibrary project with views?
2. PreviewsModule should be only dynamicLibrary to show previews?
3. If SharedViews will be staticLibrary and PreviewsModule will be dynamicLibrary can I to make import Shared into Previews to get views and make #Preview files there?

[marekfort]

@marekfort

My MainApp should import only staticLibrary project with views?

You shouldn’t need to import any preview-only related module if you have those, yes.

@marekfort

PreviewsModule should be only dynamicLibrary to show previews?

What is the point of having a PreviewsModule? Previews should be as close to the code they are previewing – I feel a module dedicated to previews is somewhat of an antipattern.

@marekfort

If SharedViews will be staticLibrary and PreviewsModule will be dynamicLibrary can I to make import Shared into Previews to get views and make #Preview files there?

Yes, you should be able to, but again, this is not a setup I’d recommend.

@marekfort

I found many projects from fixtures but nothing helps me. Maybe I misunderstood something?

One thing I’m missing here is also – what exactly doesn’t work? How is your issue manifesting?

[Stan]

I think I got it and found solution. @marekfort could you check is it right way?
At first my project folders:

MyApp/
├── Project.swift
├── Workspace.swift
├── Modules/
│   ├── App/
│   ├── SharedViews/
│   └── Previews/
└── Tuist/

All modules I make as targets and described in Project.swift file. So:

1. App - has .app product
2. SharedViews - has .framework product
3. Previews - has also …framework product

All works fine. Also, for now I think it is redundant to make separeted Previews module because SharedViews is individual module and can show SwiftUI previews without building the main app bundle.

Is it right approach? How I can improve it? For now I’m enjoyed and get all that I wanted at the start of the my investigation.

[marekfort]

@Stan

Also, for now I think it is redundant to make separeted Previews module because SharedViews is individual module and can show SwiftUI previews without building the main app bundle.

Exactly, that’s the setup I’d consider adoptiong.

@Stan

Is it right approach? How I can improve it? For now I’m enjoyed and get all that I wanted at the start of the my investigation.

For better app launch times, you might want to consider making SharedViews a static framework instead of a dynamic one – but a dynamic framework is better for development (and it certainly makes previews more reliable). I suggest reading the following documentation page for the pros/cons of static/dynamic frameworks: Dependencies · Projects · Develop · Guides · Tuist