BuddyPress.org

Hi @danbp thanks for reply.

Tried the code you wrote in the link above and it works fine. But as with the one referenced in my first post it reduces the string length upon display rather than preventing the user typing in a large number of characters in the first place (and the data being stored in database).

So moved onto looking at the code snippet by @henrywright for the sign up page. Would be suitable if i could convert it to work with profile fields. Got to this stage with a few q’s:

function my_textarea_validation() {
    $custom_field_id = bp_get_member_profile_data( 'field=Mini Bio' );	
	//is the use of $_POST['field_' . $custom_field_id] correct to access desired profile field?
	if ( strlen( $_POST['field_' .$custom_field_id] ) > 5 ) { 
        global $bp;
        //which $bp->... error message to use?
	$bp->signup->errors['field_'] = __( 'CUSTOM ERROR MESSAGE', 'buddypress' ); 
    }
}
//which hook to use? (to affect the textarea on Profile > Edit navigation tab)
add_action( '???', 'my_textarea_validation' );