Specify a root path for serving

[mbostock]

The code currently assumes that the project will be served at the root of a domain and generates absolute paths starting with slash. We should support a serve root option (different from the current source root option) that allows the site to be served from a subpath.

[pettiross]

Is there a reason to provide a different serve root instead of building with relative paths? It feels like a point of failure to have the build process managed by a viz dev need to align with the relative URL on a server that might be managed by someone else.

[mbostock]

I believe the only case where we use absolute paths currently are file attachments (including local imports that are promoted to file attachments). File attachments live in dist/_file to avoid potential namespace collision with generated HTML files. It’s true we don’t need these to be absolute paths; we could rewrite these as relative paths e.g. ../_file/foo.js.

That said, there might be some cases where we need to know the serve root regardless. For example if we want to generate a sitemap.xml (see Plot’s for example), we need to know not just the serve root but the host origin as well.

[mbostock]

I expect this will be a blocker for deploying to Observable?

[mbostock]

This is not yet fixed. Still to-do:

• A base option or some such config to specify the base path for serving the preview
• File attachment paths are still hard-coded to be under /_file