Documentation
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Overview ¶
Package hosting is what both widget demo hosts do the same way.
A host owns five decisions the SDK will not make for it — where to listen, which Origins a browser may send, which palette to resolve, how to route a stylesheet and a page, and when to stop — and every one of them has exactly one right answer once the address and the palette are known. All five are here, and no host builds a router: two hosts writing out the same three lines of mux was two chances to get the mount path, the stylesheet route or the ordering wrong.
What is deliberately not here is the interesting half: which widgets to register, which sources their declared streams resolve to, and what the page says. Two hosts disagree about all three, which is why centralising those would be centralising the demo rather than the plumbing.
Index ¶
Constants ¶
const StylesheetPath = "/widget.css"
StylesheetPath is where every widget host serves its stylesheet.
It is one constant because a host's page and its router have to agree on it, and a disagreement is a page that loads with no palette and renders every widget in the browser's default colours. A page template spells the same string in its <link>; that is the one place it is repeated, and it is repeated there because a templ attribute is markup rather than Go.
Variables ¶
This section is empty.
Functions ¶
func BrowserOrigins ¶
BrowserOrigins turns a listen address into the Origin allowlist a browser will actually send.
Deny by default is the live library's rule and a list is what honouring it costs; a request whose Origin is absent from it is refused with 403 before any per-session memory is allocated. 0.0.0.0 is a bind address and never an Origin, because no browser sends it.
func OnePalette ¶
OnePalette resolves the palette every registered widget names.
A page has one stylesheet, so two widgets naming two palettes is a decision a host cannot make for them and is reported rather than settled by taking the first. An unknown name is refused for the same reason a widget may not mint a colour: a fallback renders a plausible-looking widget in the wrong one.
func Regions ¶
func Regions( config live.Config[widget.HostState, live.AnonymousIdentity], state widget.HostState, ) []templ.Component
Regions renders every registered widget's live region from the same state and the same fragments the live path patches.
The first paint is therefore the bytes a session's first snapshot would produce, so the snapshot that arrives a moment later morphs the page to markup it already has: no flash, no placeholder, and a page that is meaningful with JavaScript disabled — it simply stops updating.
func Serve ¶
func Serve( ctx context.Context, address string, app *live.App[widget.HostState, live.AnonymousIdentity], site Site, ) error
Serve builds the two routes a widget host serves — its stylesheet and its page — mounts the live handler in front of them, and runs the result until the context ends.
The router is built here rather than by a host, because there is exactly one correct arrangement of it and two hosts writing it out was two chances to get the mount path, the stylesheet route or the ordering wrong. Nothing is handed back: a composed handler returned from here would be an interface leaving a package that has no reason to hand one out, and the only thing a caller could do with it is what this function already does.
Types ¶
type Site ¶
type Site struct {
// MountPath is where the live handler is mounted. The runtime script tag in
// the host's page template must name the same path, and a disagreement is a
// script tag that 404s and a page that loads and never updates.
MountPath string
// Palette is the one palette every registered widget named, already
// resolved by [OnePalette].
Palette widget.Palette
// Chrome is the host's own page CSS, served after the SDK's. A host that
// kept its own copy of the token mapping, the scene's structure and the
// motion gate would be hand-maintaining the one projection the SDK derives.
Chrome []byte
// Page renders the whole document from one session's state. It is the only
// field two hosts genuinely disagree about.
Page func(state widget.HostState) templ.Component
}
Site is everything a widget host serves: where the live handler is mounted, the palette its widgets named, its own page chrome, and its page.
It is a value rather than four parameters because Serve takes all four and no host has ever wanted three of them.
Source Files