convert indexedb objecstore to json for send data with post - json

Question

i must send data of an objectstore with post to a php file but i can't transform objectstore to send it.
Thanks for help
var xhttp = new XMLHttpRequest();
xhttp.open("POST", "../php/sincDATI.php", true);
var request = indexedDB.open("rsapp",1, "persistent");
request.onsuccess = function (evt) {
var db = request.result;
var tx = db.transaction(pTable,"readwrite");
var store = tx.objectStore(pTable);
*** TRAFORM store in json ????
xhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
xhttp.onreadystatechange = function() {
if (this.readyState == 4 && this.status == 200) {
};
};
xhttp.send(????);
};

Answer 1

I have found a solution for sending a JSON file, with an XMLHttpRequest transforming automatically an indexedDB objectStore:
function sendData(pTable,pMess) {
var xhttp = new XMLHttpRequest();
var sendArray=[];
var request = indexedDB.open("dbapp",1, "persistent");
request.onsuccess = function (evt) {
var db = request.result;
var tx = db.transaction(pTable,"readwrite");
var store = tx.objectStore(pTable);
var cursorRequest = store.getAll();
cursorRequest.onsuccess = function(event) {
var cursor=event.target.result;
for(var item of cursor) {
sendArray.push(item);
};
xhttp.open("POST", "../php/sincDATI.php", true);
xhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
xhttp.onreadystatechange = function() {
if (this.readyState == 4 && this.status == 200) {
$("#lblMessaggi").html("OK!"+ xhttp.responseText);
};
};
xhttp.send("pArr="+JSON.stringify(sendArray));
};
};
};