Combined topic views: /topics/business,saas,crypto (0.3.0)

README.md

@@ -236,6 +236,7 @@ All send `access-control-allow-origin: *` and need no key.
 | `/api/discoveries/{id}` | Progress of one keyword run |
 | `/api/crawlstats` | Crawler health, including the two discovery queues |
 | `/api/topics/{keyword}` | The feeds on a topic, its category breakdown, `?group=` to narrow |
+| `/api/topics/{a},{b},{c}` | Several topics (up to 10) as one: the union, each feed once, tagged-under-any first then strength summed across them; adds `topics` and `unknown`. Works on every topic surface: `/topics/a,b`, `/topics/a,b/blogs`, `/topics/a,b.rss`, the player, and the MCP `get_topic`/`topic_posts` |
 | `/topics/{keyword}/{group}.rss` | One category of a topic, as a feed — also `.atom`, `.json`, `.m3u`, `.pls` |
 | `/mcp` | MCP endpoint — and the documentation page, in a browser |
 | `/api/authors` | The people behind the feeds; `?feed={url}` finds the people behind one feed |

apps/web/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@rssamplifier/web",
-  "version": "0.2.4",
+  "version": "0.3.0",
   "private": true,
   "type": "module",
   "scripts": {

apps/web/src/app/api/queue/route.js

@@ -93,7 +93,10 @@ export async function POST(req) {
     const group = body.group ? topicGroup(body.group) : null;
     if (body.group && !group) return wantsHtml ? redirect(back) : json({ error: 'not-found' }, 404);
 
-    const rows = await q.mediaForTopic(client, String(body.topic ?? ''), {
+    // A combined view (business,saas) posts its slugs joined by commas, the
+    // same form its address uses; a single topic is a one-element list, which
+    // is the single-topic query unchanged.
+    const rows = await q.mediaForTopic(client, String(body.topic ?? '').split(','), {
       limit: PLAYLIST_LIMIT,
       kinds: group?.kinds ?? null,
     });

apps/web/src/app/api/topics/[keyword]/route.js

@@ -1,7 +1,8 @@
 import { q } from '@rssamplifier/db';
 
 import { db, siteUrl } from '../../../../lib/db.js';
-import { groupsWithFeeds, slugFromUrl, topicGroup } from '../../../../lib/topicGroups.js';
+import { groupsWithFeeds, topicGroup } from '../../../../lib/topicGroups.js';
+import { resolveTopics, topicQueryArg, topicSegment } from '../../../../lib/topicSet.js';
 
 export const dynamic = 'force-dynamic';
 
@@ -19,22 +20,48 @@ export const dynamic = 'force-dynamic';
  * a second request, and a caller that guessed wrong can see what it should have
  * said.
  *
+ * Several topics at once — `/api/topics/business,saas,crypto` — answer in the
+ * same shape for their union (see lib/topicSet.js): every feed filed under any
+ * of them, each once, `total` counting distinct feeds. Three fields are added
+ * for a list: `topics` (each known topic with its own count and address),
+ * `unknown` (what was asked for and does not exist) and `strength` per feed is
+ * the sum across the topics. A list with nothing known is a 404; one longer
+ * than ten topics a 400.
+ *
  * @param {Request} req
  * @param {{ params: Promise<{ keyword: string }> }} ctx
  */
 export async function GET(req, { params }) {
   const { keyword } = await params;
-  const slug = slugFromUrl(keyword);
 
   const url = new URL(req.url);
   const limit = Math.min(Math.max(Number(url.searchParams.get('limit') ?? 100) || 100, 1), 500);
   const offset = Math.max(Number(url.searchParams.get('offset') ?? 0) || 0, 0);
   const group = topicGroup(url.searchParams.get('group'));
 
   const client = db();
-  const topic = await q.topicBySlug(client, slug);
+  const found = await resolveTopics(client, keyword);
+
+  if (found.error === 'too-many') {
+    return new Response(
+      JSON.stringify(
+        { error: 'too-many-topics', max: found.max, hint: `Combine at most ${found.max} topics.` },
+        null,
+        2,
+      ),
+      {
+        status: 400,
+        headers: {
+          'content-type': 'application/json; charset=utf-8',
+          'access-control-allow-origin': '*',
+        },
+      },
+    );
+  }
 
+  const topic = found.topic;
   if (!topic) {
+    const slug = found.unknown.join(',');
     return new Response(JSON.stringify({ error: 'not-found', slug }, null, 2), {
       status: 404,
       headers: {
@@ -45,11 +72,11 @@ export async function GET(req, { params }) {
   }
 
   const [rows, counts] = await Promise.all([
-    q.feedsForTopic(client, slug, { limit, offset, kinds: group?.kinds ?? null }),
-    q.topicKindCounts(client, slug),
+    q.feedsForTopic(client, topicQueryArg(topic), { limit, offset, kinds: group?.kinds ?? null }),
+    q.topicKindCounts(client, topicQueryArg(topic)),
   ]);
 
-  const base = `${siteUrl()}/topics/${encodeURIComponent(topic.slug)}`;
+  const base = `${siteUrl()}/topics/${topicSegment(topic.slug)}`;
 
   return new Response(
     JSON.stringify(
@@ -63,6 +90,20 @@ export async function GET(req, { params }) {
           ? group.kinds.reduce((sum, kind) => sum + (counts[kind] ?? 0), 0)
           : topic.feedCount,
         topicTotal: topic.feedCount,
+        // Only on a combined view, so a single topic's answer is byte for byte
+        // what it was.
+        ...(topic.multi
+          ? {
+              topics: (topic.topics ?? []).map((t) => ({
+                slug: t.slug,
+                keyword: t.keyword,
+                feedCount: t.feedCount,
+                page: `${siteUrl()}/topics/${encodeURIComponent(t.slug)}`,
+                api: `${siteUrl()}/api/topics/${encodeURIComponent(t.slug)}`,
+              })),
+              unknown: topic.unknown ?? [],
+            }
+          : {}),
         group: group?.segment ?? null,
         groups: groupsWithFeeds(counts).map(({ group: entry, count }) => ({
           group: entry.segment,
@@ -92,6 +133,8 @@ export async function GET(req, { params }) {
           // a phrase counted across its writing.
           source: f.source,
           strength: Number(f.count ?? 0),
+          // Which of the listed topics this feed is filed under.
+          ...(topic.multi ? { topics: String(f.topics ?? '').split(',').filter(Boolean) } : {}),
           page: `${siteUrl()}/${f.slug}`,
         })),
       },

apps/web/src/app/topics/[keyword]/TopicListing.jsx

@@ -14,6 +14,7 @@ import Share from '../../Share.jsx';
 import { Avatar } from '../../Thumb.jsx';
 import { feedImage } from '../../../lib/thumbs.js';
 import { jsonLdScript } from '../../../lib/jsonld.js';
+import { topicQueryArg, topicSegment } from '../../../lib/topicSet.js';
 
 /** Feeds per page. Matches the category pages. */
 export const PAGE_SIZE = 60;
@@ -71,24 +72,30 @@ function formatTitle(ext, what) {
  * moment one of them grew a feature, and the sub-groups exist precisely because
  * there are now eight of them per topic.
  *
+ * A combined view (/topics/business,saas,crypto) is the same page over the
+ * union of its topics — see lib/topicSet.js. What it adds is a link to each
+ * topic it combines and a note naming any that do not exist; what it leaves
+ * out is everything keyed on one topic's slug (following it, its webring).
+ *
  * @param {{
- *   topic: { slug: string, keyword: string, feedCount: number },
+ *   topic: import('../../../lib/topicSet.js').ResolvedTopic,
  *   counts: Record<string, number>,
  *   group?: import('../../../lib/topicGroups.js').TOPIC_GROUPS[number]|null,
  *   page?: number,
  * }} props
  */
 export default async function TopicListing({ topic, counts, group = null, page = 1 }) {
   const client = db();
-  const slug = encodeURIComponent(topic.slug);
+  const slug = topicSegment(topic.slug);
+  const multi = Boolean(topic.multi);
 
   const base = group ? `/topics/${slug}/${group.segment}` : `/topics/${slug}`;
   const total = group
     ? group.kinds.reduce((sum, kind) => sum + (counts[kind] ?? 0), 0)
     : topic.feedCount;
 
   const [rows, user] = await Promise.all([
-    q.feedsForTopic(client, topic.slug, {
+    q.feedsForTopic(client, topicQueryArg(topic), {
       limit: PAGE_SIZE,
       offset: (page - 1) * PAGE_SIZE,
       kinds: group?.kinds ?? null,
@@ -99,7 +106,7 @@ export default async function TopicListing({ topic, counts, group = null, page =
   // Only asked once we know there is someone to ask about. A signed-out visitor
   // still gets the button — the endpoint sends them to sign in and back here —
   // so this decides what it says rather than whether it appears.
-  const follow = user
+  const follow = user && !multi
     ? await alerts.topicFollowState(client, String(user.id), topic.slug, group?.segment ?? '')
     : { following: false, alerts: false };
 
@@ -154,15 +161,40 @@ export default async function TopicListing({ topic, counts, group = null, page =
       <p className="eyebrow">
         {group ? (
           <>
-            <a href="/topics">Topic</a> · <a href={`/topics/${slug}`}>{topic.keyword}</a>
+            <a href="/topics">{multi ? 'Topics' : 'Topic'}</a> ·{' '}
+            <a href={`/topics/${slug}`}>{topic.keyword}</a>
           </>
         ) : (
-          <a href="/topics">Topic</a>
+          <a href="/topics">{multi ? 'Topics' : 'Topic'}</a>
         )}
       </p>
       <h1>{heading}</h1>
       <p className="lede">{lede}</p>
 
+      {/* What this combined view is made of, each topic on its own page, and
+          what was asked for that does not exist — said rather than silently
+          dropped, so a typo in one of five topics is visible. */}
+      {multi && (
+        <p className="topic-set">
+          Every feed filed under any of:{' '}
+          {(topic.topics ?? []).map((t, i) => (
+            <span key={t.slug}>
+              {i > 0 && ' · '}
+              <a href={`/topics/${encodeURIComponent(t.slug)}${group ? `/${group.segment}` : ''}`}>
+                {t.keyword}
+              </a>{' '}
+              <span className="count">({t.feedCount})</span>
+            </span>
+          ))}
+          {(topic.unknown ?? []).length > 0 && (
+            <>
+              {' '}
+              — no topic called {(topic.unknown ?? []).map((u) => `"${u}"`).join(', ')}.
+            </>
+          )}
+        </p>
+      )}
+
       {/* The topic's other categories. Shown on the sub-group pages too, so
           moving between them never costs a trip back through the topic — which
           is the whole reason for cutting the topic up. Only the groups that
@@ -230,17 +262,19 @@ export default async function TopicListing({ topic, counts, group = null, page =
             form underneath, so it works with JavaScript off; with JavaScript it
             flips in place rather than reloading a page of sixty feeds to change
             two words on one button. */}
-        <FollowControls
-          endpoint="/api/follows/topics"
-          kind="topic"
-          slug={topic.slug}
-          segment={group?.segment ?? ''}
-          following={follow.following}
-          alerts={follow.alerts}
-          signedIn={Boolean(user)}
-          next={base}
-          label="Follow this topic"
-        />
+        {!multi && (
+          <FollowControls
+            endpoint="/api/follows/topics"
+            kind="topic"
+            slug={topic.slug}
+            segment={group?.segment ?? ''}
+            following={follow.following}
+            alerts={follow.alerts}
+            signedIn={Boolean(user)}
+            next={base}
+            label="Follow this topic"
+          />
+        )}
 
         <Share
           url={pageUrl}
@@ -251,12 +285,16 @@ export default async function TopicListing({ topic, counts, group = null, page =
 
         {/* The same feeds as a webring: hops, an OPML, and a viewer that frames
             them one at a time. Both pages exist; this is the door between them. */}
-        <a className="button" href={`/ring/${encodeURIComponent(topic.slug)}`}>
-          Webring
-        </a>
-        <a className="button" href={`/view/${encodeURIComponent(topic.slug)}`}>
-          View webring
-        </a>
+        {!multi && (
+          <>
+            <a className="button" href={`/ring/${encodeURIComponent(topic.slug)}`}>
+              Webring
+            </a>
+            <a className="button" href={`/view/${encodeURIComponent(topic.slug)}`}>
+              View webring
+            </a>
+          </>
+        )}
       </div>
 
       <Ad format={AD_TEXT} />
@@ -283,6 +321,7 @@ export default async function TopicListing({ topic, counts, group = null, page =
                 <span>
                   {f.item_count} {f.category === 'podcast' ? 'episodes' : 'posts'}
                 </span>
+                {multi && f.topics && <span>{String(f.topics).split(',').join(', ')}</span>}
               </div>
             </a>
           );

apps/web/src/app/topics/[keyword]/TopicPlayer.jsx

@@ -4,6 +4,7 @@ import { db } from '../../../lib/db.js';
 import { currentUser } from '../../../lib/auth.js';
 import { PLAYLIST_LIMIT } from '../../../lib/topicFeed.js';
 import { playlistEntry, playerPath, queueRuntime, rawPlaylistPath } from '../../../lib/player.js';
+import { topicQueryArg, topicSegment } from '../../../lib/topicSet.js';
 import PlaylistPlayer from '../../PlaylistPlayer.jsx';
 import QueueAll from '../../QueueAll.jsx';
 
@@ -16,16 +17,16 @@ import QueueAll from '../../QueueAll.jsx';
  * they differ only in the filter, and two copies would drift.
  *
  * @param {{
- *   topic: { slug: string, keyword: string, feedCount: number },
+ *   topic: import('../../../lib/topicSet.js').ResolvedTopic,
  *   group?: { segment: string, kinds: string[], heading: string, item: string }|null,
  * }} props
  */
 export default async function TopicPlayer({ topic, group = null }) {
   const client = db();
-  const slug = encodeURIComponent(topic.slug);
+  const slug = topicSegment(topic.slug);
 
   const [rows, user] = await Promise.all([
-    q.mediaForTopic(client, topic.slug, {
+    q.mediaForTopic(client, topicQueryArg(topic), {
       limit: PLAYLIST_LIMIT,
       kinds: group?.kinds ?? null,
     }),

apps/web/src/app/topics/[keyword]/[group]/page.jsx

@@ -1,9 +1,9 @@
 import { notFound } from 'next/navigation';
-import { q } from '@rssamplifier/db';
 
 import { db, siteUrl } from '../../../../lib/db.js';
 import { feedAlternates } from '../../../../lib/subscribe.js';
-import { slugFromUrl, topicGroup } from '../../../../lib/topicGroups.js';
+import { topicGroup } from '../../../../lib/topicGroups.js';
+import { resolveTopicsWithCounts, topicSegment } from '../../../../lib/topicSet.js';
 import { pageNumber } from '../../../CategoryIndex.jsx';
 import TopicListing from '../TopicListing.jsx';
 
@@ -19,7 +19,7 @@ export const dynamic = 'force-dynamic';
  *
  * @param {{ params: Promise<{ keyword: string, group: string }> }} props
  * @returns {Promise<{
- *   topic: { slug: string, keyword: string, feedCount: number },
+ *   topic: import('../../../../lib/topicSet.js').ResolvedTopic,
  *   counts: Record<string, number>,
  *   group: NonNullable<ReturnType<typeof topicGroup>>,
  *   total: number,
@@ -31,12 +31,7 @@ async function resolve({ params }) {
   if (!group) return null;
 
   const client = db();
-  const slug = slugFromUrl(keyword);
-
-  const [topic, counts] = await Promise.all([
-    q.topicBySlug(client, slug),
-    q.topicKindCounts(client, slug),
-  ]);
+  const { topic, counts } = await resolveTopicsWithCounts(client, keyword);
   if (!topic) return null;
 
   const total = group.kinds.reduce((sum, kind) => sum + (counts[kind] ?? 0), 0);
@@ -58,12 +53,14 @@ export async function generateMetadata(props) {
   if (!found) return { title: 'Not found' };
 
   const { topic, group, total } = found;
-  const page = `${siteUrl()}/topics/${encodeURIComponent(topic.slug)}/${group.segment}`;
+  const page = `${siteUrl()}/topics/${topicSegment(topic.slug)}/${group.segment}`;
   const heading = `${topic.keyword}: ${group.heading.toLowerCase()}`;
 
   return {
     title: heading,
     description: `${total} ${group.noun} in the RSS Amplifier directory cover ${topic.keyword}.`,
+    // Out of the index for a combined view; see the whole-topic page.
+    ...(topic.multi ? { robots: { index: false, follow: true } } : {}),
     alternates: {
       canonical: page,
       types: feedAlternates(page, heading),