Universal¹ Web Transclusion
(AKA A{n,rbitrar}y-Side Inclusion)
transcluding HTTP resources server- and/or client-side, with Web Components
$ npm install
$ npm start
NB: This is merely a proof of concept at this point.
When the server renders an HTML document, the result is optionally piped through
a transclusion resolver (either within the application or via a proxy) which
attempts to replace any occurrence of <a is="embeddable-link" href="…" …> with
the corresponding contents by dereferencing the URI.
The server-side algorithm is fairly straightforward (see resolver.js):
- parse document to next occurrence of
<a is="embeddable-link" href="…" …> - memorize URI as well as (start, end) index
- request URI (asynchronously)
- GOTO #1
- handle response:
- transclude contents into document at index, replacing the link
- if there is no positive response (e.g. due to timeout²), continue without modifying the document
- after all responses have been processed³, send the document to the client
When client receives the document, it can attempt to transclude any unresolved
transclusions (e.g. because the respective server-side requests timed out), e.g.
using the custom element provided by embed.js, if JavaScript is available —
otherwise
end users will still able to use the respective links,
which might also include fallback content.
¹ as in isomoprhic
² optionally determined based on the link's priority attribute — which might
also suppress server-side transclusion, leaving that to the client for the
respective link
³ this prevents streaming, but could later be optimized