handsontable .getData by div id is not working?

Question

I'm trying to get the filled data using the div id but it is throwing $container.data(...) is undefined.

<!-- ... -->
    <div id="app" style="width: 500px; height: 200px;"></div>   
</div>
<button id="app_id" onclick="json()">Json</button>

I have tried the following code to get the filled data:

var rowHead = colAr;
var colHead = dataObj[idname].col;
var data = [[]],
    container = document.getElementById("app"),
    selectFirst = document.getElementById('selectFirst'),
    rowHeaders = document.getElementById('rowHeaders'),
    colHeaders = document.getElementById('colHeaders'),
    hot;

hot = new Handsontable(container, {
    minRows:rowHead.length,
    minCols:colHead.length,
    startRows: 5,
    startCols: 5,
    rowHeaders: rowHead,
    colHeaders: colHead,
    contextMenu: false,
    outsideClickDeselects: false,
    removeRowPlugin: true
});
hot.loadData(data);

function json() {
    var $container = $("#app");
    var handsontable = $container.data('handsontable').getData();
    console.log(handsontable);
/*
    var htContents = hot.getData();
    var jsonObj = {};
    for (var i = 0; i < htContents.length; i++)
    {
    jsonObj[rowHead[i]] = htContents[i];
    }
    console.log(jsonObj);
*/  


}

But it is throwing error, instead I tried with another option:

var cont = hot.getData();
console.log(cont);

This is working. But I have multiple tables so I need to get the data by the particular table using the div id, what is the problem in my code?

Answer 1

Finally got the answer

 $('#app .ht_master tbody td').each(function(){
    var text = $(this).text();
 });