L is not defined in leaflet-iiif

[jcoyne]

When loaded as a module. It may depend on L as a constant (via Leaflet)

https://github.com/projectblacklight/spotlight/blob/main/vendor/assets/javascripts/leaflet-iiif.js#L7

The original is in @mejackreed's repo: https://github.com/mejackreed/Leaflet-IIIF

[mejackreed]

Has an absolute hard dependency on Leaflet

[jcoyne]

Hi @mejackreed 👋 I'm wondering it it can be patched to import L from "leaflet-src.esm.js" rather than expectingL to be defined globally?

[mejackreed]

For the fork here in Spotlight, sure? Leaflet plugins usually follow a pattern to extend L from an expected global existence. Maybe there are other patterns out there to handle this?

Also, I have no understanding anymore about how Rails expects this to work 😉

// leaflet-iiif importer

import L from "leaflet-src.esm.js";
import leaflet-iiif

[jcoyne]

@mejackreed Using ESM modules seems to be the path forward for Leaflet:

import leaflet/dist/leaflet-src.esm.js explicitly instead to take advantage [of modules]; ESM by default will come in v2

https://github.com/Leaflet/Leaflet/releases/tag/v1.9.2

[jcoyne]

Here is a PR that would resolve this: mejackreed/Leaflet-IIIF#93