Browser-WASM Support for QuestPDF

[xer4yx]

Hello👋! I wanted to add a functionality for my Blazor application where I can generate a PDF from my page content. My initial plan is to:

1. Use the library in the client side (Blazor WASM)
2. Create a Service class and inject it to page
3. Retrieve the byte[] from the generated document and use it as a MemoryStream
4. Create a DotNetStreamReference from the MemoryStream
5. Pass the stream reference to a JS script using JSRuntime.InvokeVoidAsync
6. The script gets the stream reference converting to: stream reference => array buffer => blob => url object (string).
7. URL object then is used in the HTMLAnchorElement as a <a /> tag and downloads it

But the problem is on setting my license, I encounter error saying:

blazor.webassembly.js:1 PDF Generation Error: System.TypeInitializationException: The type initializer for 'QuestPDF.Settings' threw an exception.
blazor.webassembly.js:1  ---> System.TypeInitializationException: The type initializer for 'QuestPDF.Helpers.Helpers' threw an exception.
blazor.webassembly.js:1  ---> System.Exception: The QuestPDF library has encountered an issue while loading one of its dependencies.
blazor.webassembly.js:1 
blazor.webassembly.js:1 Your runtime is not supported by QuestPDF. The following runtimes are supported: win-x86, win-x64, linux-x64, linux-arm64, linux-musl-x64, osx-x64, osx-arm64. Your current runtime is detected as 'browser-wasm'. 
blazor.webassembly.js:1  ---> System.DllNotFoundException: QuestPdfSkia
blazor.webassembly.js:1    at QuestPDF.Skia.SkNativeDependencyCompatibilityChecker.ExecuteNativeCode()
blazor.webassembly.js:1    at QuestPDF.Helpers.NativeDependencyCompatibilityChecker.CheckIfExceptionIsThrownWhenLoadingNativeDependencies()
blazor.webassembly.js:1    --- End of inner exception stack trace ---
blazor.webassembly.js:1    at QuestPDF.Helpers.NativeDependencyCompatibilityChecker.<TestOnce>g__ThrowCompatibilityException|18_0(Exception innerException)
blazor.webassembly.js:1    at QuestPDF.Helpers.NativeDependencyCompatibilityChecker.TestOnce()
blazor.webassembly.js:1    at QuestPDF.Helpers.NativeDependencyCompatibilityChecker.Test()
blazor.webassembly.js:1    at QuestPDF.Skia.SkNativeDependencyCompatibilityChecker.Test()
blazor.webassembly.js:1    at QuestPDF.Helpers.Helpers..cctor()
blazor.webassembly.js:1    --- End of inner exception stack trace ---
blazor.webassembly.js:1    at QuestPDF.Settings..cctor()
blazor.webassembly.js:1    --- End of inner exception stack trace ---

I was thinking if there will be plan on creating a support for browser-wasm?

I've tried to downgrade the version of QuestPDF to 2023.12.X - 2023.9.X but to no avail it produces the same type of error in the console.

[girlpunk]

Are you sure you want to generate the PDF in the user's browser? That may require a fair amount of resources and will take some time as a result.

[fingers10]

Yes I also need the option to generate PDF in browser

[xer4yx]

Now that I'm fully using the library to the project I'm working with, its either:

1. Use a Blazor Server on your application instead of Blazor WASM
2. If migrating from Blazor WASM to Server is arduous or currently not possible due to constraints in your application, you can create a backend application that will handle your request and send it as a file stream.

Either way, after a fair amount of time of integration and contemplating, I think creating a backend service for your front-end application that integrates a PDF generation feature is the best way to go really since the server is the one handling the CPU bound operations when creating the file.

[russkyc]

@xer4yx I wish I had seen this sooner, I was able to get it working in an older project in this configuration:

<ItemGroup>
        <NativeFileReference Include="$(HarfBuzzSharpStaticLibraryPath)/3.1.34/st/*.a" />
        <PackageReference Include="HarfBuzzSharp.NativeAssets.WebAssembly" Version="7.3.0" />
        <PackageReference Include="QuestPDF" Version="2023.10.2" />
        <PackageReference Include="SkiaSharp.Views.Blazor" Version="2.88.6" />
</ItemGroup>

project is here: Timely just in case someone else stumbles upon this.