How to specify only for the new added row in datatable?

ElyaNordin

Currently I'm using forEach that will execute the code for every row by row of the datatable. My problem now is, how can I execute the code only for a specific row that newly added and ignoring the previously added row?

function InStockk() {
          _datatableData.forEach(function (rowData) {
              var ID = rowData.ID;

              var quantity = parseInt($("#txtQuantity" + ID).val(), 10);
              if (!quantity) { quantity = 0; }

              var id = $("#txtItem"+ID).select2("val");
              console.log("stock id :" + id);

             $.ajax({
               url: "../WS/wsQuotation.asmx/GetStockInfo",
               type: 'GET',
               data: {
                   StockID: id ,
               },
               success: function (data) {

                   var json = JSON.parse(data);

                   var instock = parseFloat(json[0]["Inventory_Quantity"]);

                   $("#txtStock" + ID).val(instock - quantity);

               },
              error: function (xhr, status, error) {
                    alert(xhr.responseText + ":  " + error);
               }
              });
         });
    }

rf1234

Assuming you want to process the maximum ID

function InStockk() {    
    
    if ( typeof _datatableData[0] !== 'undefined' ) {
        
        //sort array of objects descending by ID
        _datatableData.sort(function(a, b){ 
          return a.ID == b.ID ? 0 : + (a.ID < b.ID) || -1;
        }); 
        
        var ID = _datatableData[0].ID;

        var quantity = parseInt($("#txtQuantity" + ID).val(), 10);
        if (!quantity) { quantity = 0; }

        var id = $("#txtItem"+ID).select2("val");
        console.log("stock id :" + id);

        $.ajax({
            url: "../WS/wsQuotation.asmx/GetStockInfo",
            type: 'GET',
            data: {
                StockID: id ,
            },
            success: function (data) {

            var json = JSON.parse(data);

            var instock = parseFloat(json[0]["Inventory_Quantity"]);

            $("#txtStock" + ID).val(instock - quantity);
            },
            error: function (xhr, status, error) {
                alert(xhr.responseText + ":  " + error);
            }
        });
    }
}

rf1234

If you may not change the sequence of _datatableData this could work:

function InStockk() {   
    
    var ID = -1;
    _datatableData.forEach(function (rowData) {
        if ( rowData.ID > ID ) {
            ID = rowData.ID;
        }
    });
    
    if ( ID >= 0 ) {
         
        //sort array of objects descending by ID
        _datatableData.sort(function(a, b){
          return a.ID == b.ID ? 0 : + (a.ID < b.ID) || -1;
        });
         
        var ID = _datatableData[0].ID;
 
        var quantity = parseInt($("#txtQuantity" + ID).val(), 10);
        if (!quantity) { quantity = 0; }
 
        var id = $("#txtItem"+ID).select2("val");
        console.log("stock id :" + id);
 
        $.ajax({
            url: "../WS/wsQuotation.asmx/GetStockInfo",
            type: 'GET',
            data: {
                StockID: id ,
            },
            success: function (data) {
 
            var json = JSON.parse(data);
 
            var instock = parseFloat(json[0]["Inventory_Quantity"]);
 
            $("#txtStock" + ID).val(instock - quantity);
            },
            error: function (xhr, status, error) {
                alert(xhr.responseText + ":  " + error);
            }
        });
    }
}

rf1234

sorry the second post was wrong; forgot to delete the sorting code:

function InStockk() {  
     
    var ID = -1;
    _datatableData.forEach(function (rowData) {
        if ( rowData.ID > ID ) {
            ID = rowData.ID;
        }
    });
     
    if ( ID >= 0 ) {
        
        var quantity = parseInt($("#txtQuantity" + ID).val(), 10);
        if (!quantity) { quantity = 0; }
  
        var id = $("#txtItem"+ID).select2("val");
        console.log("stock id :" + id);
  
        $.ajax({
            url: "../WS/wsQuotation.asmx/GetStockInfo",
            type: 'GET',
            data: {
                StockID: id ,
            },
            success: function (data) {
  
            var json = JSON.parse(data);
  
            var instock = parseFloat(json[0]["Inventory_Quantity"]);
  
            $("#txtStock" + ID).val(instock - quantity);
            },
            error: function (xhr, status, error) {
                alert(xhr.responseText + ":  " + error);
            }
        });
    }
}

But why are you not using an event? Assuming you use Editor as well.
This would give you the ID of the row created:
https://editor.datatables.net/reference/event/create

yourEditor.on( 'create', function ( e, json, data, ID) {
 .... your code ...
});