How to update data after ajax reload using initComplete callback for DataTables when using ajax source data? - datatables

Question

I’m using a select object to trigger an ajax reload for a DataTable.
I need to add individual column searching with select inputs for a given column (not for every column) but the select is filled with the previous ajax response.
How can I update the data that the initCompleteFunction callback uses to fill the select input in the individual column searching?
// this is the select that triggers the ajax.reload
$('#proveedor').on('change', function () {
$datatable
.DataTable()
.ajax
.reload(initCompleteFunction, false);
});
// this is my initCompleteFunction callback
function initCompleteFunction(settings, json){
var api = new $.fn.dataTable.Api( settings );
api.columns().every( function () {
var column = this;
if ($(column.header()).hasClass('select')) {
var select = $('<select><option value="">' + $(column.header()).html() + '</option></select>')
.appendTo( $(column.footer()).empty() )
.on( 'change', function () {
var val = $.fn.dataTable.util.escapeRegex(
$(this).val()
);
column
.search( val ? '^'+val+'$' : '', true, false )
.draw();
return false;
} );
//this is the part that keeps previous data insted of the new one from the ajax reload
column.data().unique().sort().each( function ( d, j ) {
select.append( '<option value="'+d+'">'+d+'</option>' );
} );
}
});
}
// and this is how I’m setting the DataTable
var $datatable = $('#table_materiales');
$datatable
.on('xhr.dt', function ( e, settings, json, xhr ) {
initCompleteFunction(settings, json);
})
.DataTable({
"ajax": {
"url": "http://my_endpoint",
"dataSrc": "",
"type": "POST",
"data": {
id_proveedor: function () {
return $('#proveedor').val(); // to get the value in the provider’s filter (select)
}
}
},
"columns": [
{
data: 'row_num'
},{
className: "select",
data: 'material'
},
// here goes the rest of the column definitions
],
"paging": false,
'columnDefs': [
{
'targets': 0,
'checkboxes': {
'selectRow': true
}
}
],
'select': {
'style': 'multi'
},
'order': [
[3, 'asc']
],
"createdRow": function (row, data, dataIndex) {
$(row).attr('data-id-material', data.id_material);
$(row).attr('data-pedido_sugerido', data.pedido_sugerido);
$(row).attr('id', 'id_' + data.row_num);
if(data['status_de_tiempo']=='FUERA'){
$(row).addClass('redClass');
}
},
});

Answer 1

During research I found that the xhr.dt event is triggered before the ajax.reload() is completed so the data keeps outdated when the select for the individual column search is populated. See this reference
User grozni posted this on April, 2019:
I have used console logs and was able to confirm that the event fires before the XHR event concludes, and does not pull the latest JSON. I used XHR tracking where I could to get around it but it's still really inconvenient and complicating matters alot. I need to be able to do certain things after the data is loaded and drawn. Perhaps it's worthy of a bug report
I found this post (See here) where user conangithub needed to
count DataTables item after I reload DataTable successfully
User lovecoding-git suggested this approach:
table= $('#example').DataTable();
$('#example').on('draw.dt', function() {
console.log(table.ajax.json().recordsTotal);
});
So, for my own issue, instead of
.on('xhr.dt', function ( e, settings, json, xhr ) {
initCompleteFunction(settings, json);
})
I wrote
.on('draw.dt', function ( e, settings, json, xhr ) {
initCompleteFunction(settings, json);
})
Et voilà.
I got the needed solution.