Making a button visible based on number of records in datatable - asp.net-mvc

Question

I am using jquery datatable in asp.net mvc and i want to show a submit button which will be saving the data to the database only if there is atleast one row in the datatable.
I am trying this code, however its not working
<tr id="trbtnSubmit">
<td colspan="9" align="center">
<input type="submit" name="btnSubmit" value="Save"
class="btn btn-edit btn-text" />
</td>
</tr>
<script>
var PopUp, dataTable;
$(document).ready(function () {
dataTable = $("#tblCustomerList").DataTable({
"ajax": {
"url": "/Customer/GetCustomers",
"type": "GET",
"data": "json"
},
"lengthChange": false,
"pageLength": 10,
"columns": [
{ "data": "Number" },
{ "data": "Name" },
{ "data": "fileName" },
{ "data": "mD5Hash" },
{ "data": "dataSizeInGB" },
{
"data": "Id",
"render": function () {
return "<a href='#'><i class='fa fa-eye'></a></i><a href='#' style='margin-left:5px'><i class='fa fa-pencil'></i></a><a href='#' style='margin-left:5px'><i class='fa fa-trash'></a></i>";
},
"orderable": false,
"width": "40px"
},
],
"language": {
"emptyTable": "No Customers , click on <b>New Customer</b> to add Customers"
}
});
var table = $('#tblCustomerList').DataTable();
if (!table.data().any()) {
$('#trbtnSubmit').hide();
} else {
$('#trbtnSubmit').show();
}
});
</script>

Answer 1

Since you didn't specify the version of datatables, I assume it's v1.10.
And there are 2 side notes I want to make before going into your problem:
Difference between .datatable() and .DataTable()
Enable server-side processing
Difference Between .datatable() and .DataTable()
I saw you declared another variable, var table, at the bottom of your sample code to get another instance of DataTables and check if there is any data? You actually don't need to.
.DataTable() returns a DataTables API instance, while .datatable() returns a jQuery object.
So if you intent to make usages on the DataTables APIs after you initialize the table, you can just use the varirable you declared from the beginning, var dataTable since you used .DataTable() way.
Enable Server-side Processing
Server-side processing is enabled by turning on the serverSide option, and configuring the ajax option. You're missing the first one, whose default is false.
So you might need to add serverSide option in your code:
dataTable = $("#tblCustomerList").DataTable({
serverSide: true,
ajax: {
...
},
...
});
Enough said. Now looking at your problem ...
DataTables Callbacks
There are many ways to achieve what you want to do, and I like to use callbacks so that you can configure your DataTables in one place.
There are lots of callbacks you can use, and the one I would use is drawCallback:
dataTable = $("#tblCustomerList").DataTable({
serverSide: true,
...,
language: {
emptyTable: "No Customers , click on <b>New Customer</b> to add Customers"
},
drawCallback: function(settings) {
$('#trbtnSubmit').toggle(settings.aoData.length > 0);
}
});
Hopefully my code is readable enough without any additional explanations :)