Formatter  

`$config` is optional because extensions subclass this and call `parent::__construct()` with the two arguments that existed before it was added. When it is absent the forum's address is resolved from the container instead, so those subclasses keep working untouched.

Flush the cache so that the formatter components are regenerated.

Build and cache the formatter now, rather than leaving it to the first post that needs rendering.

Compiling the renderer can be expensive on a forum with many extensions, and it happens lazily inside whichever request first renders a post after the cache was cleared. On a tight web memory limit that request can hit a fatal and fail silently. Warming here — from `cache:clear`, where the limit is usually higher — keeps that cost out of the render path.

Let the link template carry attributes decided when a post is rendered.

Whether a link points back at this forum is not known when the post is written — the forum may since have moved — so `rel`, `target` and `class` are worked out at render time and copied through here. A theme that replaces this template needs to copy them too, or links lose the treatment.

Show a link to a discussion as the discussion it points at.

A pasted address says nothing useful in the middle of a sentence, so where the writer pasted one bare — leaving the address as the link's own text — it is shown as `#123` instead, with the post number alongside it when the link points at a particular reply. When the writer chose their own words for the link, those words are what appears; the label replaces an address, never a sentence.

The markup for a discussion link that is showing its label.

Get a TextFormatter component ("renderer" or "parser" or "js").

Get the formatter JavaScript.

Decide how each link in a post should be treated, based on where it goes.

Only fills in what has not already been set, so an extension rendering callback — which runs before this — keeps the last word on any link.

Pick out the discussion a URL points at, if it points at one.

Matches the shape the discussion route declares: an id, optionally followed by a slug that carries no meaning here, and optionally a post number after it.

The forum's favicon, if one has been uploaded.

Looked up once per request for the same reason as the forum's address: this is consulted for every discussion link on the page.

The forum's host and base path.

`Config::url()` builds a fresh Uri on every call, and this is consulted once per link in every post on the page, so the answer is kept rather than rebuilt. It cannot change within a request.

Does this URL point back at the forum itself?

Host and path both have to match: a forum installed at example.com/forum does not own example.com/shop. The scheme is ignored, since a forum reachable over both http and https is still one forum, and a link is not a different destination for having been copied before the certificate was installed.

Converts a plain text string (with or without Markdown) to it's HTML equivalent.