CODEWITHSUNDEEP
javascriptcursorindexeddb
Nikita Mikhailovskiy
Nikita Mikhailovskiy

Reputation: 13

IDB: openCursor() is not a function

Well, maybe I do something wrong... But this error is very confusing. I stick with: "Uncaught TypeError: requestChatHistory.openCursor is not a function at IDBOpenDBRequest.dbPromise.onsuccess"

IDBOpenRequest might inherit methods from IDBRequest...

I tried to make request without openCursor() and get the first value from it. Also tried to re-create database, use different browsers (Chrome, Edge, Firefox)

onUpgrade promise:

dbPromise.onupgradeneeded = function(event) { 
        let db = event.target.result;
        db.createObjectStore('keys', {keyPath: 'userId'});
        let chatHistory = db.createObjectStore('messages', { keyPath: "id", autoIncrement:true });
        chatHistory.createIndex("chatId", "chatId", { unique: false });
    };

There is my function with request:

async function loadSavedMessages(chatId){
        let dbPromise = idb.open('clientDB', 3);
        dbPromise.onsuccess = function() {
            let db = this.result;
            let dbTransaction = db.transaction(["messages"]);
            let messages = dbTransaction.objectStore("messages");
            let index = messages.index('chatId'); 
            let requestChatHistory = index.get(chatId);
            requestChatHistory.openCursor().onsuccess = function(event) {
                let cursor = event.target.result;
                if (cursor) {
                    console.log(cursor);
                    cursor.continue();
                }
            };
        }
    }

Function that saves data:

async function saveMessage(chatId, message, userId){
        let dbPromise = idb.open('clientDB', 3);
        dbPromise.onsuccess = function() {
            let db = this.result;
            let dbTransaction = db.transaction(["messages"], 'readwrite');
            let messages = dbTransaction.objectStore("messages");
            let mesObj = {
                chatId: chatId,
                user: userId,
                message: message,
                timestamp: Date.now()
            };
            let save = messages.add(mesObj);
            save.onerror = function(event) {
                // Handle errors!
                console.log("Something went wrong with local DB :(")
            };
            save.onsuccess = function(event) {
                // Do something with the request.result!
                console.log(`Message saved, id ${save.result}`);
            };
        }
    }

Upvotes: 1

Views: 856

Answers (1)

dumbmatter
dumbmatter

Reputation: 9673

This is your problem:

            let requestChatHistory = index.get(chatId);
            requestChatHistory.openCursor().onsuccess = function(event) {

requestChatHistory is an IDBRequest, which has no openCursor method. openCursor is on IDBIndex, like your index variable. So maybe you meant to do something like:

            index.openCursor(chatId).onsuccess = function(event) {

Upvotes: 2

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