From bdc3a65007ac97d05244572f5c09caa1c4dfd31e Mon Sep 17 00:00:00 2001
From: Jean Mertz <git@jeanmertz.com>
Date: Fri, 24 Jul 2026 00:24:35 +0200
Subject: [PATCH] feat(docs, rfd): Sync RFD index filter and search to URL

The RFD index and draft pages now reflect their filter and search state
in the URL's query string, and read that state back out on load.
Visiting a link like `/rfd/?search=plugin` shows the same filtered list
the link's author saw, instead of always falling back to whatever was
last stored in the visitor's own session.

URL params take precedence over the existing sessionStorage-based
restore, so a shared link still wins on first load. Updates use
`replaceState` rather than `pushState`, so typing in the search box
doesn't flood browser history with an entry per keystroke.

Signed-off-by: Jean Mertz <git@jeanmertz.com>
---
 docs/.vitepress/theme/RfdIndex.vue | 43 ++++++++++++++++++++++++------
 1 file changed, 35 insertions(+), 8 deletions(-)

diff --git a/docs/.vitepress/theme/RfdIndex.vue b/docs/.vitepress/theme/RfdIndex.vue
index d61aca0dc..9e1b00775 100644
--- a/docs/.vitepress/theme/RfdIndex.vue
+++ b/docs/.vitepress/theme/RfdIndex.vue
@@ -1,5 +1,6 @@
 <script setup>
-import { ref, computed, watch } from 'vue'
+import { ref, computed, watch, onMounted } from 'vue'
+import { inBrowser } from 'vitepress'
 
 const props = defineProps({
     entries: { type: Array, required: true },
@@ -17,19 +18,45 @@ function stored(key, fallback) {
 
 const k = (name) => `${props.storageKey}-${name}`
 
-const filter = ref(stored(k('filter'), 'all'))
-const search = ref(stored(k('search'), ''))
-const showSummaries = ref(stored(k('summaries'), 'true') === 'true')
-
-watch(filter, v => { try { sessionStorage.setItem(k('filter'), v) } catch {} })
-watch(search, v => { try { sessionStorage.setItem(k('search'), v) } catch {} })
-watch(showSummaries, v => { try { sessionStorage.setItem(k('summaries'), String(v)) } catch {} })
+// URL query params take precedence over sessionStorage, so a shared link like
+// /rfd/?search=plugin shows the same filtered list for everyone.
+function fromUrl(name) {
+    if (!inBrowser) return null
+    return new URLSearchParams(window.location.search).get(name)
+}
 
 // Default to descending by id so the newest RFDs sit at the top.
 const sortKey = ref('num')
 const sortAsc = ref(false)
 const categories = ['all', 'design', 'decision', 'guide', 'process']
 
+const urlFilter = fromUrl('filter')
+const filter = ref(categories.includes(urlFilter) ? urlFilter : stored(k('filter'), 'all'))
+const search = ref(fromUrl('search') ?? stored(k('search'), ''))
+const showSummaries = ref(stored(k('summaries'), 'true') === 'true')
+
+// Mirror the toolbar state into the URL so the current view is shareable.
+// replaceState (not pushState) keeps typing from flooding the history stack.
+function syncUrl() {
+    if (!inBrowser) return
+    const params = new URLSearchParams(window.location.search)
+    if (filter.value !== 'all') params.set('filter', filter.value)
+    else params.delete('filter')
+    if (search.value.trim()) params.set('search', search.value)
+    else params.delete('search')
+    const qs = params.toString()
+    const url = window.location.pathname + (qs ? `?${qs}` : '') + window.location.hash
+    window.history.replaceState(window.history.state, '', url)
+}
+
+watch(filter, v => { try { sessionStorage.setItem(k('filter'), v) } catch {}; syncUrl() })
+watch(search, v => { try { sessionStorage.setItem(k('search'), v) } catch {}; syncUrl() })
+watch(showSummaries, v => { try { sessionStorage.setItem(k('summaries'), String(v)) } catch {} })
+
+// State restored from sessionStorage isn't in the URL yet; sync once so the
+// address bar always matches what's on screen.
+onMounted(syncUrl)
+
 const showCategory = computed(() => filter.value === 'all')
 
 const columns = computed(() => {