Add Elastic FTS option (#877)

Author: samtstern

README.md

@@ -188,9 +188,9 @@ Uses a Realtime Database trigger.
 Integrates the Bit.ly API to shorten URLs automatically as they are added to the database.
 Uses a Realtime Database trigger.
 
-### Full-text search via Algolia for [Realtime Database](/fulltext-search) or [Firestore](/fulltext-search-firestore)
+### Full-text search for [Realtime Database](/fulltext-search) or [Firestore](/fulltext-search-firestore)
 
-Enable full-text search on Firebase Database data or Firestore documents by using an Algolia hosted search service.
+Enable full-text search on Firebase Database data or Firestore documents by using a hosted search service.
 Uses a Realtime Database or Firestore trigger.
 
 ### [User data cleanup](/user-data-cleanup)

fulltext-search-firestore/functions/elastic.js

@@ -0,0 +1,87 @@
+/**
+ * Copyright 2021 Google Inc. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the 'License');
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an 'AS IS' BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+const functions = require("firebase-functions");
+
+// [START init_elastic]
+const { Client } = require("@elastic/elasticsearch");
+
+// Initialize Elastic, requires installing Elastic dependencies:
+// https://github.com/elastic/elasticsearch-js
+//
+// ID, username, and password are stored in functions config variables
+const ELASTIC_ID = functions.config().elastic.id;
+const ELASTIC_USERNAME = functions.config().elastic.username;
+const ELASTIC_PASSWORD = functions.config().elastic.password;
+
+const client = new Client({
+  cloud: {
+    id: ELASTIC_ID,
+    username: ELASTIC_USERNAME,
+    password: ELASTIC_PASSWORD,
+  }
+});
+// [END init_elastic]
+
+// [START update_index_function_elastic]
+// Update the search index every time a blog post is written.
+exports.onNoteCreated = functions.firestore.document('notes/{noteId}').onCreate(async (snap, context) => {
+  // Get the note document
+  const note = snap.data();
+
+  // Use the 'nodeId' path segment as the identifier for Elastic
+  const id = context.params.noteId;
+
+  // Write to the Elastic index
+  client.index({
+    index: "notes",
+    id,
+    body: note,
+  });
+});
+// [END update_index_function_elastic]
+
+// [START search_function_elastic]
+exports.searchNotes = functions.https.onCall(async (data, context) => {
+  const query = data.query;
+
+  // Search for any notes where the text field contains the query text.
+  // For more search examples see:
+  // https://www.elastic.co/guide/en/elasticsearch/client/javascript-api/current/search_examples.html
+  const searchRes = await client.search({
+    index: "notes",
+    body: {
+      query: {
+        query_string: {
+          query: `*${query}*`,
+          fields: [
+            "text"
+          ]
+        }
+      }
+    }
+  });
+
+  // Each entry will have the following properties:
+  //   _score: a score for how well the item matches the search
+  //   _source: the original item data
+  const hits = searchRes.body.hits.hits;
+
+  const notes = hits.map(h => h["_source"]);
+  return {
+    notes: notes
+  };
+});
+// [END search_function_elastic]

fulltext-search-firestore/functions/package.json

@@ -2,6 +2,7 @@
   "name": "full-text-search",
   "description": "Full text search for Firestore",
   "dependencies": {
+    "@elastic/elasticsearch": "^7.13.0",
     "algoliasearch": "^4.0.3",
     "cors": "^2.8.5",
     "express": "^4.17.1",

fulltext-search-firestore/public/index.js

@@ -26,7 +26,7 @@ function unauthenticated_search(query) {
 
   // Perform an Algolia search:
   // https://www.algolia.com/doc/api-reference/api-methods/search/
-return index
+  return index
     .search({
       query
     })
@@ -90,6 +90,17 @@ function search(query) {
   }
 }
 
+function searchElastic(query) {
+   // [START search_elastic]
+   const searchNotes = firebase.functions().httpsCallable('searchNotes');
+   searchNotes({ query: query })
+     .then((result) => {
+       const notes = result.data.notes;
+       // ...
+     });
+   // [END search_elastic]
+}
+
 // Other code to wire up the buttons and textboxes.
 
 document.querySelector('#do-add-note').addEventListener('click', function() {