SwiftUI Preview stuck on preparing...

[JkMulti]

When cas ios sdk is integrated, the preview stops working in Canvas. It does not give any errors or any report. It is stuck on Preparing editor functionality.

[Str4tos]

Hi @JkMulti, thank you for opening this issue.

We haven’t observed any specific SwiftUI preview problems that appear to be caused by the CAS.AI framework.

One potential cause might be related to CocoaPods and Xcode's sandboxing, which is enabled by default. To ensure proper behavior of CocoaPods dependencies, please make sure that ENABLE_USER_SCRIPT_SANDBOXING = NO is set in your app target's build settings.

If the issue persists, please share a Diagnostics Report with us so we can investigate further. You can do this by clicking the "Diagnostics" button in the error banner in the Previews canvas area, or via the menu: Editor > Canvas > Diagnostics, if the banner is not visible.

Looking forward to your update and happy to assist further.

[JkMulti]

I have already set ENABLE_USER_SCRIPT_SANDBOXING = NO. And I started with a new SwiftUI default project without pods. opened .xcodeproj file and preview shows. Then i added pods according to cas.ai documentation. Opened .xcworkspace, project is build successfully and ad shows in real device along with ui. But in preview it stucks on preparing editor. Then i disintegrate pods and preview works again.

Can you test by creating a new project, integrate pods cas.ai ads and confirm again. I am using Xcode Version 16.3 (16E140) and iPhone 16 pro ios 18.2 simulator for preview. I will be thankful.

[Str4tos]

We tested a new SwiftUI project in Xcode 16.3 with the CAS.AI dependency added.
The first launch of the preview takes more time — roughly equivalent to building the app for a device — due to the compiling of all frameworks from the dependencies. However, we didn't encounter any other issues.

Could you please share any additional information, perhaps a code sample or a minimal project that reproduces the issue?

[JkMulti]

My project is default SwiftUI code.
`//
// ContentView.swift
// Wallbyte
//
// Created by Junaid on 16/04/2025.
//

          import SwiftUI
          
          struct ContentView: View {
              var body: some View {
                  
                  VStack(spacing: 20) {
                      
                      Text("Welcome to SwiftUI")
                          .font(.title)
                          .fontWeight(.bold)
                      
                      Button(action: {
                          print("Button tapped")
                      }) {
                          Text("Tap Me")
                              .padding()
                              .frame(maxWidth: .infinity)
                              .background(Color.blue)
                              .foregroundColor(.white)
                              .cornerRadius(12)
                      }
                      
                  }
                  .padding()
              }
          }
          
          #Preview {
              ContentView()
          }

And here is my pods:

        source 'https://github.com/CocoaPods/Specs.git'
        source 'https://github.com/cleveradssolutions/CAS-Specs.git'
        
        
        use_frameworks! :linkage => :static
        $casVersion = '~> 3.9.10'
        
        target 'Wallbyte' do
          pod 'CleverAdsSolutions-SDK/Optimal', $casVersion
        end

[Str4tos]

Hi @JkMulti,
We've been able to reproduce the SwiftUI Preview hang when using Optimal Ads Solutions. Unfortunately, we're unable to resolve the issue as it stems from transitive dependencies of the ad frameworks.

Please note that this problem does not occur when integrating only the CleverAdsSolutions-Base pod during development.

As a workaround, you can enable Editor > Canvas > Use Legacy Previews Execution in Xcode. This should prevent the preview from hanging.

[JkMulti]

Hi, thanks for the update. Is CleverAdsSolutions-Base better than Optimal? Which one should i choose. I want maximum revenue and fast loading.

[Str4tos]

The CleverAdsSolutions-Base dependency adds only the core framework to your project, which does not include live ads. It is intended for development purposes and allows you to view test ads only.

To monetize your app, you’ll need to include mediation adapters for CAS. The Optimal dependency is a balanced solution that includes several mediation adapters.
If you need more details, feel free to reach out to your account manager.

[DeHazar]

Maybe need to add in documentation page with creating development scheme and release scheme, where include more CAS providers