mostrar titulo de mundo en index (fixes #3)

src/components/WorldLink.svelte

@@ -0,0 +1,18 @@
+<script>
+  import { inject } from "regexparam";
+  import { getWorldY } from "../lib/doc";
+  import { titleStore } from "../lib/titleStore";
+  import { routes } from "../lib/routes";
+
+  /** @type {import("../lib/doc").WorldIdentifier} */
+  export let world;
+
+  $: title = titleStore(getWorldY(world).ydoc, "page/index");
+</script>
+
+<a
+  href={inject(routes.Page, {
+    worldId: world.room,
+    pageId: "index",
+  })}>{$title || world.room}</a
+>

src/lib/getTitle.js

@@ -0,0 +1,26 @@
+import { yDocToProsemirrorJSON } from "y-prosemirror";
+import { Node } from "prosemirror-model";
+import { schema } from "../editor/schema";
+
+/**
+ * @param {import("yjs").Doc} ydoc
+ * @param {string} name
+ * @returns {string=}
+ */
+export function getTitle(ydoc, name) {
+  const json = yDocToProsemirrorJSON(ydoc, name);
+  const node = Node.fromJSON(schema, json);
+  /** @type {any} */
+  let titleNode = null;
+  node.descendants((node) => {
+    if (titleNode) return false;
+    if (node.type.name === "heading" && node.attrs.level === 1) {
+      titleNode = node;
+      return false;
+    }
+  });
+  if (titleNode) {
+    // prettier-ignore
+    return /** @type {Node} */(titleNode).textContent;
+  }
+}

src/lib/titleStore.js

@@ -0,0 +1,32 @@
+import { getTitle } from "./getTitle.js";
+import { makeYdocStore } from "./makeYdocStore";
+
+/**
+ * @param {import("yjs").Doc} ydoc
+ * @param {string} id
+ * @returns {import("svelte/store").Readable<string | null>}
+ */
+export function titleStore(ydoc, id) {
+  /** @type {(() => void) | null } */
+  let observer = null;
+  /** @type {import("yjs").AbstractType<any> | null} */
+  let y = null;
+
+  /** @type {string|null} */
+  let title = null;
+
+  return makeYdocStore(
+    (_, __, ydoc) => {
+      const setTitle = () => (title = getTitle(ydoc, id) || null);
+      if (!y) {
+        setTitle();
+        y = ydoc.getXmlFragment(id);
+        observer = setTitle;
+        y.observeDeep(observer);
+      }
+
+      return title;
+    },
+    () => observer && y?.unobserveDeep(observer)
+  )(ydoc);
+}

src/lib/worldStorage.ts

@@ -1,11 +1,16 @@
-import type { WorldIdentifier } from "./doc";
+import { getWorldY, type WorldIdentifier } from "./doc";
 
 const localStorageKey = "schreiben-worlds";
 
 export function loadWorlds(): Promise<WorldIdentifier[]> {
   let json = localStorage.getItem(localStorageKey);
   if (!json) json = "[]";
-  return Promise.resolve(JSON.parse(json));
+  const worlds = JSON.parse(json);
+  for (const world of worlds) {
+    // empezar a cargar el Ydoc
+    getWorldY(world);
+  }
+  return Promise.resolve(worlds);
 }
 
 export async function writeWorlds(

src/views/ChooseWorld.svelte

@@ -2,6 +2,7 @@
   import { inject } from "regexparam";
   import { loadWorlds } from "../lib/worldStorage";
   import { routes } from "../lib/routes";
+  import WorldLink from "../components/WorldLink.svelte";
 
   const worldsPromise = loadWorlds();
 </script>
@@ -13,12 +14,7 @@
   <ul>
     {#each worlds as world}
       <li>
-        <a
-          href={inject(routes.Page, {
-            worldId: world.room,
-            pageId: "index",
-          })}>{world.room}</a
-        >
+        <WorldLink {world} />
       </li>
     {/each}
     <li><a href={routes.CreateWorld}>Crear mundo</a></li>