indexedDB highest keypath

Question

I have a database inside indexedDB filled using an Emberjs adapter. I have set the keypath like this:

this.addModel(App.Device, { keyPath: \'key\' });

Answer 1

Use objectStore.openKeyCursor with the direction "prev":

const openCursorRequest = store.openKeyCursor(null, 'prev')
openCursorRequest.onsuccess = () => {
  const cursor = openCursorRequest.result
  const maxKey = cursor && cursor.key
  // use maxKey...
}

Using Promise:

const getMaxKey = (db, storeName) => new Promise((resolve, reject) => {
  const tx = db.transaction(storeName, 'readonly')
  const store = tx.objectStore(storeName)
  const openCursorRequest = store.openKeyCursor(null, 'prev')
  openCursorRequest.onsuccess = () => {
    const cursor = openCursorRequest.result
    resolve(cursor && cursor.key)
  }
  openCursorRequest.onerror = () => {
    reject(openCursorRequest.error)
  }
})