Feature: An icon endpoint for frontend JavaScript
Description
Where frontend JavaScript learns the identifier of an icon only after the page was rendered, from data it loads or from a choice of the visitor, the JSON icon map of the page cannot carry it. The JavaScript asks the new icon endpoint below the base of the site or site language instead:
GET https://example.com/_academic/icons.json?i=tx-academicbase-action-add,tx-academicbase-info-phone&s=small&v=<token>i names up to 32 identifiers, separated by commas, s the size, small
when it is left out, and v the version token of the served icons. The answer
is a JSON object in the shape of the JSON icon map, for the identifiers that
are served, in the order asked for. It serves the same icons with the same
markup as the view helper. A malformed identifier, more than 32 of them or an
unknown size are answered with 400, a method other than GET and HEAD
with 405, and a site in maintenance mode with 503.
The endpoint answers before the frontend user authentication: it never starts
a session and never sets a cookie, so a proxy or a CDN can cache it like a
file. The answer is cached for a year
(Cache-) when v is the current
version token, and for five minutes otherwise, both with an ETag that a
matching If- answers with 304. The view helper hands the endpoint
of the current site language and the current token to the JavaScript with
endpoint="1":
<ab:frontendIconMap identifiers="{}" endpoint="1" />It adds data- and data- to the
data block. The token changes with the frontend icon registrations, the
modification time of their files and of the classes of their providers, and
with every TYPO3 update and every change of composer..
The path, the parameters, the answer and the caching of the endpoint are public API of this extension, see What is public API.
Impact
The path _academic/ below the base of every site is answered by
this extension, a page with that slug can no longer be reached there. A web
server or CDN rule that serves *. as static files has to pass this path
on to TYPO3, the way sitemap. usually is, see
The icon endpoint. Web nodes that do not share one build compute
different tokens, so a page rendered on one node gets the five-minute answer
from another.