Datatable export multiple searched and selected rows - php

Question

i am not able to export multiple time searched and selected data to CSV.
i am fetching data from database which has more than 1000 records.
so for example, if i select 2 rows on page one then i search for some other record and select that record and export but it is only exports searched record not the records from the page one.
$('#master tfoot th').each(function() {
var title = $(this).text();
$(this).html('<input type="text" placeholder="Search ' + title + '" />');
});
// DataTable
var master = $('#master').DataTable({
dom: 'Blfrtip',
buttons: [
'copy',
'csv',
'excel',
'pdf',
{
extend: 'print',
text: 'Print all (not just selected)',
exportOptions: {
modifier: {
selected: null
}
}
}
],
select: true
});
// Apply the search
master.columns().every(function() {
var that = this;
$('input', this.footer()).on('keyup change', function() {
if (that.search() !== this.value) {
that
.search(this.value)
.draw();
}
});
});

Answer 1

This is a known limitation when using processing on the server-side. In this case the datatable-object only knows the data of the current draw. This is the reason you are only able to export the visible/rendered content of the table.
If you want to export the data from all currently selected rows, you could listen for the select.dt and deselect.dt events of the datatable and store the row-data of the selection in an extra array from that you can create the csv-data for an export.
Further information and examples about the events can be found in the oficial doumentation:
select event
deselect event
Whenever the selection changes, an event will be dispatched. We can listen for this select-event, check if the selection is of type row and add the data to an array or object. Since we want to prevent duplicates, we should choose an unique key for the data (based on an id or some other data of the row).
Depending on how you have implemented your datatable and the processing, you have to watch for the deselect-event too. And maybe add some special handling of the pagination inside the datatable, so that rows on other pages are displayed as selected when you navigate to them again.
let selectedRows = {}; // holds all the data of selected rows
let table = $('#example').DataTable({ /* settings */ });
table.on('select', function(e, dt, type, indexes) {
if ( type === 'row' ) {
let data = table.rows( indexes ).data();
for (let item of data) {
let key = item[0] + '_' + item[2] + '_' + item[2]; // an unique key, for example built from: eventName, firstName and lastName
if (!(key in selectedRows)) {
selectedRows[key] = item;
}
}
}
});
// Todo: handle deselect and maybe pagination...
You can then export that data inside the browser with javascript.
let csvData = 'COLUMN_1,COLUMN_2,COLUMN_3, ..., COLUMN_N';
for (let row of selectedRows) {
csvData = csvData + '\n'
+ '"' + row.column_1 + '",'
+ '"' + row.column_2 + '",'
+ '"' + row.column_3 + '",'
/* ... */
+ '"' + row.column_N + '",';
// Create temporary download-element
let a = window.document.createElement('a');
a.href = window.URL.createObjectURL(new Blob([csvData], { type: 'text/csv;charset=utf-8;' }));
a.download = 'export.csv';
a.display = 'none';
// Append element to body and click it
document.body.appendChild(a);
a.click();
// Remove element from body
document.body.removeChild(a);
Note: If your data has strings that includes double quotes ", you have to escape them with an extra double quote "".