JavaScript: Proper way to use an async loader callback

[rben01]

I am using the JS version of Sjsonnet and am running into an issue trying to call SjsonnetMain.interpret with an async loader callback. I have Files that I want to read, but the only good way to read them these days is through FileReader, which only provides an async interface. Is there a way to use this with Sjsonnet, or do I have to preload all of my files’ contents as strings so that I can make the callback synchronous?

[stephenamar-db]

Yup, I noticed that when I tried to implement some of missing methods in JS.
As far as I can tell, scalajs does not have any way to do that easily.
We would effectively need to rewrite sjsonnet using futures/promises

[CertainLach]

In jrsonnet I have dynamic preloader for that, given a jsonnet file, it parses it to AST, extracts all the referenced imports, and loads them asynchronously. Then it parses every loaded file, extracts all the import expressions... etc recursively

Then during code executions import expressions just have everything in preload cache.

The same approach should work well for scala, there is no limitations given that jsonnet doesn't support dynamic imports.

[stephenamar-db]

mmh, yeah, maybe implement an asynchronous interface for https://github.com/databricks/sjsonnet/blob/master/sjsonnet/src/sjsonnet/Importer.scala#L10