On Caldera Forms, when you export entries as CSV.
It cannot be open perfectly with excel because it missing BOM in file prefix.
Therefore, we have to intercept the process and here is how to.
At the file wp-content/plugins/caldera-forms/classes/admin.php.
There is a function to export the CSV here.
What we need to intercept is during the process of writing the CSV file about line 1411.
Here is some chunk of the code.
header("Pragma: public");
header("Expires: 0");
header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
header("Cache-Control: private",false);
header("Content-Type: text/csv charset=$encoding;");
header("Content-Disposition: attachment; filename=\"" . sanitize_file_name( $form['name'] ) . ".csv\";" );
header("Content-Transfer-Encoding: binary");
$df = fopen("php://output", 'w');
After the $df starts the file, we put BOM to it with this code.
// Put BOM to the file
fprintf($df, chr(0xEF).chr(0xBB).chr(0xBF));
The continue the process.
There is the complete chuck of the edited code.
header("Pragma: public");
header("Expires: 0");
header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
header("Cache-Control: private",false);
header("Content-Type: text/csv charset=$encoding;");
header("Content-Disposition: attachment; filename=\"" . sanitize_file_name( $form['name'] ) . ".csv\";" );
header("Content-Transfer-Encoding: binary");
$df = fopen("php://output", 'w');
// Put BOM to the file
fprintf($df, chr(0xEF).chr(0xBB).chr(0xBF));
$csv_data = apply_filters( 'caldera_forms_admin_csv', array(
'headers' => $headers,
'data' => $data
), $form );
$data = $csv_data[ 'data' ];
$headers = $csv_data[ 'headers' ];
fputcsv($df, $headers);
The file maybe replaced when the plugin is updated, so make sure you stop auto update by locking the file with chmod to 444 and do manual update instead and reprocess this again after plugin update.
Try this in function.php, it might help:
add_filter( 'caldera_forms_admin_csv', function( $csv_data, $form ){
//replace with your form id
if( 'CF5a57806b565d2' === $form[ 'ID' ] ){
$df = fopen("php://output", 'w');
fprintf($df, chr(0xEF).chr(0xBB).chr(0xBF));
}
return $csv_data;
}, 10, 2 );