indexed-db-as-promised v0.1.0

indexed-db-as-promised

A thin wrapper around IndexedDB, making it much more pleasant to use by returning Promise-likes. Inspired by ideas in indexeddb-promised, but written with the SyncPromise library to avoid issues with the transaction lifetime.

This is not an official Google product.

Installation

npm install --save indexed-db-as-promised

Usage

The APIs mirror native IndexedDB's, just returning a promise-like everywhere you would want one.

import indexedDBP from "indexed-db-as-promised";

indexedDBP.open('database', 1, {
  upgrade(db, { transaction, oldVersion, newVersion }) {
    const people = db.createObjectStore('people', { autoIncrement: true, keyPath: 'id' });
    people.createIndex('ssn', 'ssn', { unique: true });
    people.createIndex('lastName', 'last');

    people.add({ first: 'Jane', last: 'Smith', ssn: '111-11-1111' });
  }
}).then((db) => {
  // Get the Jane's record
  return db.transaction('people').run((tx) => {
    // #run returns a Promise like that will resolve to whatever we return in
    // this block.
    const ssn = tx.objectStore('people').index('ssn');
    return ssn.get('111-11-1111');
  }).then((record) => {
    console.log(record); // => { first: 'Jane', last: 'Smith', ssn: '111-11-1111' }

    // Let's add someone, then get the total number of Smiths.
    return db.transaction('people', 'readwrite').run((tx) => {

      const store = tx.objectStore('people');
      return store.put({ first: 'John', last: 'Smith', ssn: '111-11-1112' })
        .then((key) => {
          console.log(key); // => 2

          return store.index('lastName').count(IDBKeyRange.only('Smith'));
        });
    });
  }).then((count) => {
    console.log(count); // => 2

    // Let's iterate over everyone.
    return db.transaction('people').run((tx) => {

      // Let's gather all our SSNs with a cursor.
      const open = tx.objectStore('people').openCursor();
      return open.iterate((cursor) => {
        const record = cursor.value;

        // Continue/advance (if you want to), or don't and early-exit iteration.
        cursor.continue();

        return record.ssn;
      }).then((ssns) => {
        console.log(ssns); // => ['111-11-1111', '111-11-1112']
      });
    });
  }).then(() => {
    // Let's close our connection now.
    db.close();
  });
});

License

Apache 2.0