datatable and jquery doesn't working - php

Question

Guys I'm driving crazy with this code:
I'm trying to populate my datagrid with the datatable plugin but I'm not understanding why it doesn't working. I have a message whith:
DataTables warning: table id=item_data - Invalid JSON response.
$(document).ready(function() {
$('#item_data').DataTable( {
"processing": true,
"serverSide": true,
"ajax":{
url:"item_fetch.php",
type:"POST"
},
"columnDefs":[
{
"targets":[7, 8, 9],
"orderable":false,
},
],
"pageLength": 10
});
});
<script src="https://cdn.datatables.net/1.10.16/js/dataTables.bootstrap.min.js"></script>
<script src="https://cdn.datatables.net/1.10.16/js/jquery.dataTables.min.js"></script>
<script src="https://code.jquery.com/jquery-1.12.4.js"></script>
<table id="item_data" class="table table-bordered table-striped">
<thead>
<tr>
<th>Item Code</th>
<th>Item Description</th>
<th>Product Line</th>
<th>Purchase Standard Cost</th>
<th>Last Receipt</th>
<th>Status</th>
<th></th>
<th></th>
<th></th>
</tr>
</thead>
<?php //include("item_list.php"); ?>
</table>
Theoretically item_fetch execute the query to populate my datagrid but, the java code doesn't reading the table id.
Above my item_fetch code
<?php
//item_fetch.php
include('phpfunc/database_connection.php');
include('phpfunc/function.php');
$query = '';
$output = array();
$query .= "
SELECT * FROM item
INNER JOIN i_prodline ON i_prodline,prodline_id = item.item_prodline
";
if(isset($_POST["search"]["value"]))
{
$query .= 'WHERE i_prodline.prodline_cod LIKE "%'.$_POST["search"]["value"].'%" ';
$query .= 'OR i_prodline.prodline_desc LIKE "%'.$_POST["search"]["value"].'%" ';
$query .= 'OR item.item_code LIKE "%'.$_POST["search"]["value"].'%" ';
$query .= 'OR item.item_desc LIKE "%'.$_POST["search"]["value"].'%" ';
}
if(isset($_POST['order']))
{
$query .= 'ORDER BY '.$_POST['order']['0']['column'].' '.$_POST['order']['0']['dir'].' ';
}
else
{
$query .= 'ORDER BY item_code DESC ';
}
if($_POST['length'] != -1)
{
$query .= 'LIMIT ' . $_POST['start'] . ', ' . $_POST['length'];
}
$statement = $connect->prepare($query);
$statement->execute();
$result = $statement->fetchAll();
$data = array();
$filtered_rows = $statement->rowCount();
foreach($result as $row)
{
$status = '';
if($row['item_status'] == 'active')
{
$status = '<span class="label label-success">Active</span>';
}
else
{
$status = '<span class="label label-danger">Inactive</span>';
}
$sub_array = array();
$sub_array[] = $row['item_code'];
$sub_array[] = $row['item_desc'];
$sub_array[] = $row['prodline_cod'];
$sub_array[] = $row['item_standardcost'];
$sub_array[] = $row['item_datareceipt'];
$sub_array[] = $status;
$sub_array[] = '<button type="button" name="view" id="'.$row["item_id"].'" class="btn btn-info btn-xs view">View</button>';
$sub_array[] = '<button type="button" name="update" id="'.$row["item_id"].'" class="btn btn-warning btn-xs update">Update</button>';
$sub_array[] = '<button type="button" name="delete" id="'.$row["item_id"].'" class="btn btn-danger btn-xs delete" data-status="'.$row["item_status"].'">Delete</button>';
$data[] = $sub_array;
}
function get_total_all_records($connect)
{
$statement = $connect->prepare('SELECT * FROM item');
$statement->execute();
return $statement->rowCount();
}
$output = array(
"draw" => intval($_POST["draw"]),
"recordsTotal" => $filtered_rows,
"recordsFiltered" => get_total_all_records($connect),
"data" => $data
);
echo json_encode($output);
?>
Please how can I fix it? I'm not understanding where is the mistake.

Answer 1

Looks like you left some debugging echo in your php code that is producing invalid JSON (thus the message from Datatable API).
Please comment line 32 in your php code.
Here is how it should look like later:
<?php
//item_fetch.php
include('phpfunc/database_connection.php');
include('phpfunc/function.php');
$query = '';
$output = array();
$query .= "
SELECT * FROM item
INNER JOIN i_prodline ON i_prodline,prodline_id = item.item_prodline
";
if(isset($_POST["search"]["value"]))
{
$query .= 'WHERE i_prodline.prodline_cod LIKE "%'.$_POST["search"]["value"].'%" ';
$query .= 'OR i_prodline.prodline_desc LIKE "%'.$_POST["search"]["value"].'%" ';
$query .= 'OR item.item_code LIKE "%'.$_POST["search"]["value"].'%" ';
$query .= 'OR item.item_desc LIKE "%'.$_POST["search"]["value"].'%" ';
}
if(isset($_POST['order']))
{
$query .= 'ORDER BY '.$_POST['order']['0']['column'].' '.$_POST['order']['0']['dir'].' ';
}
else
{
$query .= 'ORDER BY item_code DESC ';
}
//forgot to comment out debug echos
//echo $query;
if($_POST['length'] != -1)
{
$query .= 'LIMIT ' . $_POST['start'] . ', ' . $_POST['length'];
}
$statement = $connect->prepare($query);
$statement->execute();
$result = $statement->fetchAll();
$data = array();
$filtered_rows = $statement->rowCount();
foreach($result as $row)
{
$status = '';
if($row['item_status'] == 'active')
{
$status = '<span class="label label-success">Active</span>';
}
else
{
$status = '<span class="label label-danger">Inactive</span>';
}
$sub_array = array();
$sub_array[] = $row['item_code'];
$sub_array[] = $row['item_desc'];
$sub_array[] = $row['prodline_cod'];
$sub_array[] = $row['item_standardcost'];
$sub_array[] = $row['item_datareceipt'];
$sub_array[] = $status;
$sub_array[] = '<button type="button" name="view" id="'.$row["item_id"].'" class="btn btn-info btn-xs view">View</button>';
$sub_array[] = '<button type="button" name="update" id="'.$row["item_id"].'" class="btn btn-warning btn-xs update">Update</button>';
$sub_array[] = '<button type="button" name="delete" id="'.$row["item_id"].'" class="btn btn-danger btn-xs delete" data-status="'.$row["item_status"].'">Delete</button>';
$data[] = $sub_array;
}
function get_total_all_records($connect)
{
$statement = $connect->prepare('SELECT * FROM item');
$statement->execute();
return $statement->rowCount();
}
$output = array(
"draw" => intval($_POST["draw"]),
"recordsTotal" => $filtered_rows,
"recordsFiltered" => get_total_all_records($connect),
"data" => $data
);
echo json_encode($output);
?>