Upgrade sortablejs

[fitztrev]

sortablejs is used for drag+drop reordering of study chapters

• upgrade from 1.4.2 to 1.15.2
• refactor to load with esm

[schlawg]

Better to import Sortable directly in the code that uses it. Code splitting will do the rest.

[fitztrev]

Thanks for taking a look. I just tried that to see what happens. It would download sortable.js for anyone who visits a study page.

Right now the loadEsm() call is in a conditional for only people that have permission to re-order the chapters.

Can change it if the other is preferred.

[ornicar]

It's important IMO that the dependency is only downloaded by people who can actually use it. Most study pages are loaded for viewer, not contributors. That includes broadcasts.

[schlawg]

Ok. I wanted to see if esbuild could just bundle a tiny slice of this module but apparently it's a monolith class anyway so we get the whole thing.

Let's at least get rid of the shim analyse/plugins/sortable.ts as sortablejs is already esm. It can be brought in conditionally using a plain dynamic import statement i.e. import(site.asset.url(...)).then(s => s.Sortable.whatever);

But for those who prefer eating our own dogfood, I went ahead and added an npm flag to loadEsm, which resolves to the assets/npm folder rather than assets/compiled as a base. When the init parameter is false, it's equivalent to a plain dynamic import statement like the one above.

There is also some unrelated, harmless refactoring of some names. But it should be uncontroversial. I hope you don't mind i pushed directly to your repo.