New library: stlite, a port of Streamlit to Wasm, powered by Pyodide

[whitphx]

Custom components (experimental) support finally came out! I think one of the biggest advantage of Streamlit is the custom components maintained by the community, so they must be available on stlite too

Along with it, I added the “requirements” button on the playground app so that users can install additional packages.

Now the initial sample code of the playground app has been updated where a custom component, hi-plot is installed and used for demonstration (and Matplotlib too)!

Please note that this is still experimental and not all the custom components are working, for example because

• The custom component package has C-extension. Such non-pure Python packages must be specially built for Wasm/Pyodide runtime. This is not stlite’s but Pyodide/Wasm restriction. In this case, installing the package fails (see the devtool for now).
  • For example, stmol, streamlit-echarts, or streamlit-webrtc cannot be installed due to this reason.
• The custom component frontend loads local resources dynamically after initialization.
  • For example, streamlit-ace can run and it works, but its syntax highlight does not, probably, though I haven’t investigated this issue so much.