Filter for valid NKBIP-01 events

package.json

@@ -1,6 +1,6 @@
 {
   "name": "alexandria",
-  "version": "0.0.3",
+  "version": "0.0.4",
   "private": true,
   "type": "module",
   "scripts": {

src/lib/utils.ts

@@ -1,5 +1,6 @@
 import type { NDKEvent } from "@nostr-dev-kit/ndk";
 import { nip19 } from "nostr-tools";
+
 export function neventEncode(event: NDKEvent, relays: string[]) {
   return nip19.neventEncode({
     id: event.id,
@@ -81,3 +82,27 @@ export function isElementInViewport(el: string | HTMLElement) {
     rect.right <= (window.innerWidth || document.documentElement.clientWidth)
   );
 }
+
+/**
+ * Removes `kind: 30040` index events that don't comply with the NKBIP-01 specification.
+ * @param events A set of events.
+ * @returns The filtered set of events.
+ */
+export function filterValidIndexEvents(events: Set<NDKEvent>): Set<NDKEvent> {
+  // The filter object supports only limited parameters, so we need to filter out events that
+  // don't respect NKBIP-01.
+  events.forEach(event => {
+    // Index events have no content, and they must have `title`, `d`, and `e` tags.
+    if (
+      event.content != null
+      || event.getMatchingTags('title').length === 0
+      || event.getMatchingTags('d').length === 0
+      || event.getMatchingTags('e').length === 0
+    ) {
+      events.delete(event);
+    }
+  });
+
+  console.debug(`Filtered index events: ${events.size} events remaining.`);
+  return events;
+}

src/routes/+layout.svelte

@@ -1,18 +1,17 @@
 <script>
   import "../app.css";
-  // import Login from '$lib/login.svelte';
-  import { tabs, userPublickey } from "$lib/state";
-  // import {ndk} from '$lib/ndk';
-  import { browser } from "$app/environment";
-  import { NDKNip07Signer } from "@nostr-dev-kit/ndk";
-  import { onMount } from "svelte";
   import Navigation from "$lib/components/Navigation.svelte";
+    import { onMount } from "svelte";
+
+  // Compute viewport height.
+  $: displayHeight = window.innerHeight;
+
+  onMount(() => {
+    document.body.style.height = `${displayHeight}px`;
+  });
 </script>
 
-<div class='leather h-full w-full flex flex-col items-center'>
+<div class={'leather h-full w-full flex flex-col items-center'}>
   <Navigation class='sticky top-0' />
   <slot />
 </div>
-
-<style>
-</style>

src/routes/+page.svelte

@@ -2,25 +2,23 @@
   import ArticleHeader from "$lib/ArticleHeader.svelte";
   import { FeedType, indexKind } from "$lib/consts";
   import { ndk } from "$lib/ndk";
-  import { NDKEvent, NDKRelayList, NDKRelaySet, NDKSubscriptionCacheUsage, type NDKUser } from "@nostr-dev-kit/ndk";
+  import { filterValidIndexEvents } from "$lib/utils";
-  import { Button, Dropdown, Radio } from "flowbite-svelte";
+  import { NDKEvent, NDKRelayList, NDKRelaySet, type NDKUser } from "@nostr-dev-kit/ndk";
+  import { Button, Dropdown, Radio, Skeleton } from "flowbite-svelte";
   import { ChevronDownOutline } from "flowbite-svelte-icons";
 
   const getEvents = (): Promise<Set<NDKEvent>> =>
-    $ndk.fetchEvents(
     // @ts-ignore
-      { kinds: [indexKind] },
+    $ndk.fetchEvents({ kinds: [indexKind] }).then(filterValidIndexEvents);
-    );
 
   const getEventsFromUserRelays = (userRelays: NDKRelayList): Promise<Set<NDKEvent>> => {
     const relaySet = NDKRelaySet.fromRelayUrls(userRelays!.readRelayUrls, $ndk);
 
-    // TODO: Add more filter parameters to customize the event feed.
     return $ndk.fetchEvents(
       // @ts-ignore
       { kinds: [indexKind] },
       relaySet,
-    );
+    ).then(filterValidIndexEvents);
   };
 
   const getEventsFromUserFollows = (follows: Set<NDKUser>, userRelays: NDKRelayList): Promise<Set<NDKEvent>> => {
@@ -34,7 +32,7 @@
         kinds: [indexKind]
       },
       relaySet,
-    );
+    ).then(filterValidIndexEvents);
   };
 
   const getFeedTypeFriendlyName = (feedType: FeedType): string => {
@@ -48,6 +46,19 @@
     }
   };
 
+  const getSkeletonIds = (): string[] => {
+    const skeletonHeight = 124; // The height of the skeleton component in pixels.
+
+    // Determine the number of skeletons to display based on the height of the screen.
+    const skeletonCount = Math.floor(window.innerHeight / skeletonHeight) - 2;
+
+    const skeletonIds = [];
+    for (let i = 0; i < skeletonCount; i++) {
+      skeletonIds.push(`skeleton-${i}`);
+    }
+    return skeletonIds;
+  }
+
   let user: NDKUser | null | undefined;
   let readRelays: NDKRelayList | null | undefined;
   let userFollows: Set<NDKUser> | null | undefined;
@@ -64,11 +75,17 @@
   {#key user}
     {#if user == null || readRelays == null}
       {#await getEvents()}
-        <p>Loading...</p>
+        {#each getSkeletonIds() as id}
+          <Skeleton size='lg' id={id} />
+        {/each}
       {:then events}
+        {#if events.size > 0}
           {#each Array.from(events) as event}
             <ArticleHeader {event} />
           {/each}
+        {:else}
+          <p class='text-center'>No articles found.</p>
+        {/if}
       {/await}
     {:else}
       <div class='leather w-full flex justify-end'>
@@ -86,19 +103,31 @@
       </div>
       {#if feedType === FeedType.Relays && readRelays != null}
         {#await getEventsFromUserRelays(readRelays)}
-          <p>Loading...</p>
+          {#each getSkeletonIds() as id}
+            <Skeleton size='lg' id={id} />
+          {/each}
         {:then events}
+          {#if events.size > 0}
             {#each Array.from(events) as event}
               <ArticleHeader {event} />
             {/each}
+          {:else}
+            <p class='text-center'>No articles found.</p>
+          {/if}
         {/await}
       {:else if feedType === FeedType.Follows && userFollows != null}
         {#await getEventsFromUserFollows(userFollows, readRelays)}
-          <p>Loading...</p>
+          {#each getSkeletonIds() as id}
+            <Skeleton size='lg' id={id} />
+          {/each}
         {:then events}
+          {#if events.size > 0}
             {#each Array.from(events) as event}
               <ArticleHeader {event} />
             {/each}
+          {:else}
+            <p class='text-center'>No articles found.</p>
+          {/if}
         {/await}
       {/if}
     {/if}