How to serve big files using WKURLSchemeHandler?

Question

I am using WKURLSchemeHandler to serve local files that cannot be read directly by the WkWebView. While it works fine for small files like videos, it totally freezes the application when it has to provide big files like videos.

Right now, I am reading the full file in a single step which is inappropriate for important files.

data = try Data(contentsOf: fileUrl)

How should I do in order to avoid this? Is there a way to "stream" the content of the file?

Answer 1

didReceive(Data) is special and can be called multiple times with partial data, so chunked reading/streaming is possible. It's not obvious from the docs, but they said so at their presentation uf the scheme handler feature (see 32:30): https://developer.apple.com/videos/play/wwdc2017/220/

Furthermore, WKURLSchemeTask's functions can be called on a background thread, no need to do it on the main thread (and potentially blocking the UI).

• Richard Lovejoy: Thanks a lot for your answer. Are you aware of any sample code showing how to stream data in the response?
• dube: @RichardLovejoy There is another SO question that has a sample implementation: stackoverflow.com/questions/69216563/…