Question 286219 in Javascript Question posted in
A very good W3school tutorial can be found here.

Javascript – Error when declaring a js variable/ Object (Uncaught DOMException)

My script runs into the error:

Uncaught DOMException: An attempt was made to use an object that is not, or is no longer, usable

The script should check, if the database is filled. If not fill the database with initial values. After that display the values in inputfields.
The error occures at var data = marmaInfo.result

var indexedDB = window.indexedDB
var db;
    // Open (or create) the database
    var open = indexedDB.open("marmaDB", 1);
    console.log("open Db ...");

    // Create the schema
    console.log("creating schema ...");
    open.onupgradeneeded = function() {
        db = open.result;
        var store = db.createObjectStore("marmasStore", {keyPath: "id"});
    store.createIndex('sanskrit', 'sanskrit', { unique: false });
      };

    function getObjectStore(store_name, mode) {
        var tx = db.transaction(store_name, mode);
        return tx.objectStore(store_name);
    }

    open.onsuccess = function() {
        console.log("open DB DONE");
        // Start a new transaction
        db = open.result;
        store = getObjectStore("marmasStore", 'readwrite');
        //var tx = db.transaction("marmasStore", "readwrite");
        //var store = tx.objectStore("marmasStore");
        //var index = store.index("NameIndex");

        // Initial data
        const initialMarmaData = [
            { id: "ani_ll", sanskrit: "ani"},
        ];

        // Store values
        // initial DB filling 
        
        var key = $('#marmaID').val();
        console.log("key " + key );
        var marmaInfo = store.get(key);
        //marmaInfo.onsuccess = function(evt) {
        var data = marmaInfo.result  //###### ERROR at this line ######
        if (data.sanskrit == 0){
            console.log("record " + key + ":", record);
            console.log("initial filling DB ...");
            var store = getObjectStore("marmasStore", 'readwrite');
            initialMarmaData.forEach((marma) => {
                var request = store.put(marma);
                request.onsuccess = (event) => {
                    console.log(event.target.result + " initial filling DB DONE");
                };
            });
        }
        //}
        //fill the form with DB values
        console.log("filling form ...");
        document.getElementById('sanskrit').value = data.sanskrit;
        console.log("filling form DONE");
        
      }
Tags:

2

Answers


  1. 0

    Here, if onsuccess is called before onupgradeneeded, your variable store has not been instantiated even if you give it a value. Maybe is it a problem in your case.

    However you should try to use let and const if possible, for better variable’s scope usage

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  2. 0

    It looks like you need to wait for the result of getKey to return. This code was taken from mdn web docs:

    let request = store.getKey(IDBKeyRange(yesterday, today));
  request.onsuccess = (event) => {
    let when = event.target.result;
    alert(`The 1st activity in last 24 hours was occurred at ${when}`);
  };

    The .onsuccess call essentially waits for the getKey function to return, therefor defining the result.

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