basic implementation of "similar notes" widget

db/migrations/0142__similar_notes_widget.sql

@@ -0,0 +1,2 @@
+INSERT INTO options (name, value, utcDateCreated, utcDateModified, isSynced)
+VALUES ('similarNotesWidget', '{"enabled":false,"expanded":true,"position":60}', '2018-07-29T18:31:00.874Z', '2018-07-29T18:31:00.874Z', 0);

src/public/javascripts/dialogs/options/sidebar.js

@@ -51,7 +51,8 @@ export default class SidebarOptions {
             {name: 'linkMap', title: 'Link map'},
             {name: 'noteInfo', title: 'Note info'},
             {name: 'noteRevisions', title: 'Note revisions'},
-            {name: 'whatLinksHere', title: 'What links here'}
+            {name: 'whatLinksHere', title: 'What links here'},
+            {name: 'similarNotes', title: 'Similar notes'}
         ].map(widget => {
             widget.option = this.parseJsonSafely(options[widget.name + 'Widget']) || {
                 enabled: true,

src/public/javascripts/services/sidebar.js

@@ -65,7 +65,8 @@ class Sidebar {
             import("../widgets/link_map.js"),
             import("../widgets/note_revisions.js"),
             import("../widgets/attributes.js"),
-            import("../widgets/what_links_here.js")
+            import("../widgets/what_links_here.js"),
+            import("../widgets/similar_notes.js")
         ])).map(m => m.default);
 
         const options = await optionsService.waitForOptions();

src/public/javascripts/widgets/similar_notes.js

@@ -0,0 +1,36 @@
+import StandardWidget from "./standard_widget.js";
+import linkService from "../services/link.js";
+import server from "../services/server.js";
+import treeCache from "../services/tree_cache.js";
+
+class SimilarNotesWidget extends StandardWidget {
+    getWidgetTitle() { return "Similar notes"; }
+
+    getMaxHeight() { return "200px"; }
+
+    async doRenderBody() {
+        const similarNoteIds = await server.get('similar_notes/' + this.ctx.note.noteId);
+
+        console.log(similarNoteIds);
+
+        if (similarNoteIds.length === 0) {
+            this.$body.text("No similar notes found ...");
+            return;
+        }
+
+        await treeCache.getNotes(similarNoteIds); // preload all at once
+
+        const $list = $("<ul>");
+
+        for (const similarNoteId of similarNoteIds) {
+            const $item = $("<li>")
+                .append(await linkService.createNoteLink(similarNoteId));
+
+            $list.append($item);
+        }
+
+        this.$body.empty().append($list);
+    }
+}
+
+export default SimilarNotesWidget;

src/routes/api/options.js

@@ -29,6 +29,7 @@ const ALLOWED_OPTIONS = [
     'linkMapWidget',
     'noteRevisionsWidget',
     'whatLinksHereWidget',
+    'similarNotesWidget',
     'codeNotesMimeTypes'
 ];
 

src/routes/api/similar_notes.js

@@ -0,0 +1,24 @@
+"use strict";
+
+const noteCacheService = require('../../services/note_cache');
+const repository = require('../../services/repository');
+
+async function getSimilarNotes(req) {
+    const noteId = req.params.noteId;
+
+    const note = await repository.getNote(noteId);
+
+    if (!note) {
+        return [404, `Note ${noteId} not found.`];
+    }
+
+    const results = await noteCacheService.findNotes(note.title);
+
+    return results
+        .map(r => r.noteId)
+        .filter(similarNoteId => similarNoteId !== noteId);
+}
+
+module.exports = {
+    getSimilarNotes
+};

src/routes/routes.js

@@ -34,6 +34,7 @@ const searchRoute = require('./api/search');
 const dateNotesRoute = require('./api/date_notes');
 const linkMapRoute = require('./api/link_map');
 const clipperRoute = require('./api/clipper');
+const similarNotesRoute = require('./api/similar_notes');
 
 const log = require('../services/log');
 const express = require('express');
@@ -235,6 +236,8 @@ function register(app) {
     route(POST, '/api/clipper/notes', clipperMiddleware, clipperRoute.createNote, apiResultHandler);
     route(POST, '/api/clipper/open/:noteId', clipperMiddleware, clipperRoute.openNote, apiResultHandler);
 
+    apiRoute(GET, '/api/similar_notes/:noteId', similarNotesRoute.getSimilarNotes);
+
     app.use('', router);
 }
 

src/services/app_info.js

@@ -4,7 +4,7 @@ const build = require('./build');
 const packageJson = require('../../package');
 const {TRILIUM_DATA_DIR} = require('./data_dir');
 
-const APP_DB_VERSION = 141;
+const APP_DB_VERSION = 142;
 const SYNC_VERSION = 10;
 const CLIPPER_PROTOCOL_VERSION = "1.0";