bdeshi
8a6857b2fd
An alias is a promise that an old URL keeps working, so it answers 301 to the canonical one rather than serving the same content twice (ADR-0008). Frontmatter takes a scalar or a list and tolerates surrounding slashes, because authors write both. Ambiguity is dropped, not resolved: an alias naming a real bundle, or claimed by two bundles, is logged and ignored so the real bundle keeps its URL. Aliases compose with language prefixes for free, since the resolver splits the language before the key is looked up. The redirect still fires only for an alias that exists, so a nonexistent path cannot be probed by 301 — the property prompt 3 established. Evidence: /pages/bio/ and /about/ both 301 to /pages/about/, /bn/pages/bio/ 301s to /bn/pages/about/, and /pages/nothing/ is 404.
61 lines
2.0 KiB
Go
61 lines
2.0 KiB
Go
// Package web maps requests to bundles and writes bytes. It knows content and render, and exposes
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// neither to them.
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package web
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import (
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"log/slog"
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"net/http"
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"khosra/internal/content"
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"khosra/internal/render"
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)
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// Handler serves a site.
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//
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// One mux entry, because URL shape is the resolver's business rather than the mux's: see resolve.
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func Handler(site *content.Site, r *render.Renderer) http.Handler {
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mux := http.NewServeMux()
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mux.HandleFunc("GET /", func(w http.ResponseWriter, req *http.Request) {
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serve(w, req, site, r)
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})
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return mux
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}
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// serve resolves one request and writes its bundle.
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func serve(w http.ResponseWriter, req *http.Request, site *content.Site, r *render.Renderer) {
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res, ok := resolve(req.URL.Path, site)
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if !ok {
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http.NotFound(w, req)
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return
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}
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// A redirect target only exists for a path that resolves, so check the bundle before sending one:
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// otherwise a nonexistent page answers 301 and confirms nothing.
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b, served, found := site.Lookup(res.key, res.lang)
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if res.redirect != "" && (found || res.key == "") {
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http.Redirect(w, req, res.redirect, http.StatusMovedPermanently)
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return
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}
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if !found {
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// An alias is a promise that an old URL keeps working, so it answers a permanent redirect to the
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// canonical one — and only for an alias that exists, so nothing can be probed by 301.
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if canonical, isAlias := site.Alias(res.key); isAlias {
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http.Redirect(w, req, content.URL(canonical, res.lang), http.StatusMovedPermanently)
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return
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}
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http.NotFound(w, req)
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return
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}
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out, err := r.Bundle(b, served, site.Variants(res.key))
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if err != nil {
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// A render failure degrades: log it and say nothing more to the client than that it failed
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// (conventions.md). It must never leak a template or filesystem detail.
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slog.Error("render failed", "key", b.Key, "err", err)
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http.Error(w, "internal error", http.StatusInternalServerError)
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return
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}
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w.Header().Set("Content-Type", "text/html; charset=utf-8")
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if _, err := w.Write(out); err != nil {
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slog.Warn("write failed", "key", b.Key, "err", err)
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}
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}
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