submit the form to same page

Question

I have a simple form , all I want is to submit the form to same page. I have tried reading other answers including

• action="" - wordpress says Oops! That page can’t be found.
• action="#" - wordpress says Oops! That page can’t be found.
• action="<?php echo($_SERVER["PHP_SELF"]);?>" - redirects to /index.php page
• removing action tag - wordpress says Oops! That page can’t be found.

But nothing works. What I should do now ?
This is my code

    <?php
    /*
    Plugin Name: Contact Form
    Plugin URI: http://wpgeeks.net/
    Version: 1.0
    Author: Adam
    Description: A simple contact form for testing
    */

    /*Security Note: Consider blocking direct access to your plugin PHP files by adding the following line at the top of each of them, or be sure to refrain from executing sensitive standalone PHP code before calling any WordPress functions.*/
    defined( 'ABSPATH' ) or die( 'No script kiddies please!' );



    //add_action( 'plugins_loaded', 'functionShowForm' );
function functionShowForm($atts){

    $waq_values = shortcode_atts(array(

        'color'=>'white'
    ),esc_html($atts));
    ?>

<form style="color:<?php echo $waq_values['color'];?>;" method="post" action=" ">
Name:   <input type="text" name="waq_name" placeholder="First Name">
Email:  <input type="email" name="waq_email" placeholder="[email protected]">
Password:<input type="password" name="waq_password">
<input type="submit" name="waq_submit" value="Submit">
</form>
<?php
}//function ends here

function process_wpse_194468(){
if ($_SERVER['REQUEST_METHOD']=="POST" and isset($_POST["waq_submit"])){
    $to = sanitize_email($_POST["waq_email"]);
    $subject = esc_html($_POST["waq_name"]);
    $message = $_POST["waq_password"];
    echo "Email " .$to;
    wp_mail( $to, $subject, $message );
}
}
//short code
add_shortcode('showform','functionShowForm');
add_action('init','process_wpse_194468');

?>

Answer 1

name is a WordPress query var, by submitting a form with that var set, you are changing the main query. All form elements should always be prefixed with something unique to prevent clashes like this.