oh god indexeddb why

idbtest.js

var log = console.log.bind(console);

var Database = function(name, version, upgrade) {
  var self = this;
  this.ready = new Promise(function(ok, fail) {
    var req = window.indexedDB.open(name, version);
    req.onupgradeneeded = function(db) {
      self.db_ = req.result;
      if (upgrade) upgrade();
    }
    req.onsuccess = function(db) {
      self.db_ = req.result;
      ok();
    };
    req.onerror = fail;
  });
};
Database.prototype = {
  ready: null,
  db_: null,
  createStore: function(name, schema) {
    var self = this;
    schema = schema || {};
    return new Promise(function(ok) {
      var store = self.db_.createObjectStore(name, { keyPath: schema.key, autoIncrement: schema.autoIncrement });
      if (schema.index) {
        for (var key in schema.index) {
          var options = schema.index[key] || {};
          try {
            store.createIndex(key, key, options);
          } catch(err) { console.log(err) }
        }
      }
    });
  },
  transaction_: function(stores, write) {
    return this.db_.transaction(stores, write ? "readwrite" : undefined);
  },
  put: function(store, value, key) {
    var self = this;
    return new Promise(function(ok, fail) {
      var request = self.transaction_(store, true)
      request.objectStore(store).put(value, key);
      request.oncomplete = function() {
        ok();
      };
      request.onerror = fail;
    });
  },
  get: function(table, index, key) {
    if (!key) {
      key = index;
      index = null;
    }
    var self = this;
    return new Promise(function(ok, fail) {
      var transaction = self.transaction_(table);
      var store = transaction.objectStore(table);
      var request;
      if (index) {
        try {
        request = store.index(index).get(key);
        } catch(e) { console.log(e) };
      } else {
        try {
        request = store.get(key);
        } catch(e) { console.log(e) };
      }
      transaction.oncomplete = function() {
        ok(request.result);
      };
      request.onerror = fail;
    });
  },
  getAll: function(table, bounds) {
    var self = this;
    return new Promise(function(ok, fail) {
      var transaction = self.transaction_(table);
      var store = transaction.objectStore(table);
      var items = {};
      var req = store.openCursor();
      req.onsuccess = function() {
        var cursor = req.result;
        console.log(cursor);
        if (cursor) {
          var item = cursor.value;
          var key = cursor.key;
          items[key] = item;
          cursor.continue();
        } else {
          console.log("returning");
          ok(items);
        }
      }
    });
  }
}

var db = new Database("whitman", 1, function() {
  db.createStore("files", {
    key: "track",
    autoIncrement: true,
    index: {
      filename: null
    }
  });
});

var input = document.querySelector("input");
input.addEventListener("change", function() {
  if (input.files.length) {
    var file = input.files[0];
    var reader = new FileReader();
    reader.onload = function() {
      var buffer = reader.result;
      var blob = new Blob([buffer]);
      var record = {
        blob: blob,
        filename: file.name
      };
      db.ready.then(function() {
        db.put("files", record).then(function() {
          log("complete!");
        })
      });
    };
    reader.readAsArrayBuffer(file);
  }
});

var a = document.querySelector(".get");
a.addEventListener("click", function() {
  console.log("get");
  db.ready.then(function() {
    db.getAll("files").then(function(files) {
      log(files);
    });
  });
});

Incidentally, this gets slightly nicer when we have fat-arrow functions.

db.put("objects", { id: 1 })
  .then(() => db.get("objects", 1))
  .then(result => console.log(result));