IndexedDb export function.

gistfile1.txt

exportDb = (name, cb) ->
  handler = indexedDB.open(name)

  handler.onsuccess = (sender) ->
    db        = sender.target.result
    stores    = db.objectStoreNames
    results   = {}

    transaction = db.transaction stores, "readonly"

    transaction.onerror = transaction.onabort = (event) ->
      cb event, null

    transaction.oncomplete = ->
      cb null, results

    _.each stores, (store) ->
      results[store] ||= []

      transaction.objectStore(store).openCursor().onsuccess = (event) ->
        return unless cursor = event.target.result

        results[store].push
          key   : cursor.key
          value : cursor.value

        cursor.continue()

  handler.onerror = (event) ->
    cb event, null