Question

I want to modify this code into pop up alert. Currently, this code only produce error message. I want to modify it so when course clashed, the pop up will appear

 if($clash_courses==1)
{
    $error_msg .= 'Course ';
    $c = 0;
    foreach($course_id as $id){
        $c++;
        $error_msg .= $id;
        if($c<count($course_id))
        $error_msg .= ' and ';
    }

    $error_msg .= ' have clashed.';

}   

Answer 1

 if($clash_courses==1)
{
    echo '<script type = "text/javascript">';
    $error_msg .= 'Course ';
    $c = 0;
    foreach($course_id as $id){
        $c++;
        $error_msg .= $id;
        if($c<count($course_id))
        $error_msg .= ' and ';
    }

    $error_msg .= ' have clashed.';
    echo('alert("' . htmlspecialchars(str_replace('"', '\\"', $error_msg)) . '");</script>');

}   

Not the cleanest solution, but it should work. Another solution would be to access this script via AJAX, which can then feed the error back to the client-side as an ‘error object’ or even just a simple message that the client can then alert.