Create IndexedCatDB.js

static/extensions/makcolas/IndexedCatDB.js

@@ -0,0 +1,136 @@
+(function (Scratch) {
+    'use strict';
+
+    const DB_NAME = 'IndexedCatDB';
+    const STORE_NAME = 'texts';
+
+    class IndexedCat {
+        constructor() {
+            this.db = null;
+            this._openDB();
+        }
+
+        _openDB() {
+            const request = indexedDB.open(DB_NAME, 1);
+
+            request.onupgradeneeded = (event) => {
+                const db = event.target.result;
+                if (!db.objectStoreNames.contains(STORE_NAME)) {
+                    db.createObjectStore(STORE_NAME);
+                }
+            };
+
+            request.onsuccess = (event) => {
+                this.db = event.target.result;
+                console.log('[IndexedCat] Database ready');
+            };
+
+            request.onerror = (event) => {
+                console.error('[IndexedCat] Database error:', event.target.error);
+            };
+        }
+
+        getInfo() {
+            return {
+                id: 'indexedcat',
+                name: 'IndexedCat',
+                blocks: [
+                    {
+                        opcode: 'saveText',
+                        blockType: Scratch.BlockType.COMMAND,
+                        text: 'store text [TEXT] under key [KEY]',
+                        arguments: {
+                            TEXT: { type: Scratch.ArgumentType.STRING, defaultValue: 'Hello, world!' },
+                            KEY: { type: Scratch.ArgumentType.STRING, defaultValue: 'greeting' },
+                        },
+                    },
+                    {
+                        opcode: 'loadText',
+                        blockType: Scratch.BlockType.REPORTER,
+                        text: 'load text from key [KEY]',
+                        arguments: {
+                            KEY: { type: Scratch.ArgumentType.STRING, defaultValue: 'greeting' },
+                        },
+                    },
+                    {
+                        opcode: 'deleteKey',
+                        blockType: Scratch.BlockType.COMMAND,
+                        text: 'delete key [KEY]',
+                        arguments: {
+                            KEY: { type: Scratch.ArgumentType.STRING, defaultValue: 'greeting' },
+                        },
+                    },
+                    {
+                        opcode: 'clearAll',
+                        blockType: Scratch.BlockType.COMMAND,
+                        text: 'delete all stored data',
+                        arguments: {},
+                    },
+                    {
+                        opcode: 'listKeys',
+                        blockType: Scratch.BlockType.REPORTER,
+                        text: 'list all keys',
+                        arguments: {},
+                    }
+                ],
+            };
+        }
+
+        _withStore(mode, callback) {
+            return new Promise((resolve, reject) => {
+                if (!this.db) {
+                    return reject('Database not ready yet');
+                }
+                const tx = this.db.transaction([STORE_NAME], mode);
+                const store = tx.objectStore(STORE_NAME);
+                const request = callback(store);
+                request.onsuccess = () => resolve(request.result);
+                request.onerror = () => reject(request.error);
+            });
+        }
+
+        saveText(args) {
+            return this._withStore('readwrite', (store) =>
+                store.put(args.TEXT, args.KEY)
+            ).catch(console.error);
+        }
+
+        async loadText(args) {
+            try {
+                const value = await this._withStore('readonly', (store) =>
+                    store.get(args.KEY)
+                );
+                return value || '';
+            } catch (e) {
+                console.error(e);
+                return '';
+            }
+        }
+
+        deleteKey(args) {
+            return this._withStore('readwrite', (store) =>
+                store.delete(args.KEY)
+            ).catch(console.error);
+        }
+
+        clearAll() {
+            return this._withStore('readwrite', (store) =>
+                store.clear()
+            ).catch(console.error);
+        }
+
+        async listKeys() {
+            try {
+                const keys = await this._withStore('readonly', (store) =>
+                    store.getAllKeys()
+                );
+                return keys.join(', ');
+            } catch (e) {
+                console.error(e);
+                return '';
+            }
+        }
+    }
+
+    Scratch.extensions.register(new IndexedCat());
+})(Scratch);