Cannot use rdkit-js easily in NextJS - example limitation?

[sgoodrow-zymergen]

Hi,

We are using rdkit-js for molecule image rendering. Thank you for the great library and work, we appreciate it.

I am attempting to use the library in a NextJS app. We happen to be using the new "app router" architecture, but I think this issue will exist in the legacy "pages router" architecture as well.

I am trying to use it on the server-side, not in the browser (which I have gotten to work by using the unpkg source in a script tag).

The rdkit-js loading script seems to look for the .wasm file relative to its loading route. This means that if the loading script is called from a particular nested NextJS route path, the .wasm file has to be at that path location as well.

This is not seen in the example NextJS app because the loading script is always called from /, so it is expected to be found at /chunks/app, but if you also load the script from /something, it will attempt to look for the.wasm file in /chunks/app/something.

While it is straight-forward to copy the .wasm file into that location instead, I'd really like to only ship the .wasm file once and be able to use rdkit from any path.

[ptosco]

You may call initRDKitModule as follows:

initRDKitModule({
    locateFile: () => '/path/to/RDKIt_minimal.wasm'
});

where /path/to is the location of the .wasm file on your server.
This should solve your problem.

[sgoodrow-zymergen]

Oh cool! I must've missed that when reviewing the documentation. I'll try that and report back thanks. 🙂

Would you like a PR with that updated in the type definition? https://github.com/rdkit/rdkit-js/blob/master/typescript/index.d.ts#L538

[ptosco]

I do not use TypeScript myself, but I am pretty sure @MichelML would be happy to review and eventually merge your PR :-)

[MichelML]

@ptosco thanks for this I also didn't know!

@sgoodrow-zymergen yes a PR would be appreciated, but also if you could specify this option in the main readme, I think it could help other people to be rapidly aware of this option when using rdkit-js in similar contexts as yours!

[sgoodrow-zymergen]

Apologies for the delay, here's the PR: #362

Thanks!