Stripping comment HTML before inserted into database

I believe this solution will help you. Just before the closing ?> PHP tag in your functions file, add the following code:

// Create a function to call when a comment is posted
function plc_comment_post( $incoming_comment ) {

// Next, use PHP's htmlspecialchars() function to convert the comment to plain text...
$incoming_comment['comment_content'] = htmlspecialchars($incoming_comment['comment_content']);

// ... except for single quotes, which we cannot convert to its ASCI equivalent (which is #039)
// because WP will mark the comment as spam (oh no!)
$incoming_comment['comment_content'] = str_replace( "'", ''', $incoming_comment['comment_content'] );

// return the cleaned up comment variable for WP to use
return( $incoming_comment );
}

// This will occur before a comment is displayed
function plc_comment_display( $comment_to_display ) {

// Put the single quotes back in
$comment_to_display = str_replace( ''', "'", $comment_to_display );

return $comment_to_display;

Good luck with your project.

Bob

Original Source: https://lawsonry.com/2013/06/disable-html-in-wordpress-comments.html

Thanks Bob, i’ll give that a try.

I was looking in core and came across pre_comment_content

Would this be a good approach?

add_filter( 'pre_comment_content', 'wp_filter_nohtml_kses' );