check if user email exists, and if not, stop the submit of the ninja form

Question

I've one form built with ninja forms, and I use ajax to send it. I need to check if the email introduced already exists in database (user_email), and if it exists properly, I send the form properly, but if it doesn't exist, the form isn't submitted, and I need to give the user the message like "email does not exist". The form is a survey to be completed by a registered user, who gives us a feedback about our services, but the survey is located in a page where the user can send its opinion without needed to be logged.

I'm investigating, and at the moment I have:

function example_disable_saving_subs( $save, $form_id ) {

    global $ninja_forms_processing;
    $form_id = $ninja_forms_processing->get_form_ID();
    $email = ninja_forms_get_field_by_id( 18 );

    //cuestionario feedback profesor sobre creación de un curso
    if($form_id == 3){
        if( !email_exists( $email )) {
            $save = false;
            $ninja_forms_processing->add_error('email_no_existe', 'El email no existe');
        }
    }
    return $save;
}
add_filter( 'ninja_forms_save_submission', 'example_disable_saving_subs', 2, 10 );

But I pick up the field $email without value introduced...In addition, I don't know the way to give the user the message "email does not exists".

As you see, I chose the filter ninja_forms_save_submission. Maybe this is not the correct filter. I hope your valious help. Thanks in advance, Daniel

Answer 1

thanks for your help @Renato , I give you +1 :) It's true that I can do it through the way you tell me, but I don't want to break the api of WordPress, that is, the way this cms uses javascript, php, etc etc...So, I wanted to do this through the API of ninja forms, which is the plugin I use for build this survey. Finally, I solved it...it was my mistake, because I didn't use the correct filter...Investigating few more, there's another filter much more appropiate: ninja_forms_pre_process Here is the code:

function add_change_ninja_forms_landing_page(){
    add_action( 'ninja_forms_pre_process', 'handle_custom_ninja_forms' );
}
add_action( 'init', 'add_change_ninja_forms_landing_page' );

function handle_custom_ninja_forms(){

    global $ninja_forms_processing;

    $form_id = $ninja_forms_processing->get_form_ID();  

    //if it's my form of survey
    if( $form_id == 3 ){

        $email = $ninja_forms_processing->get_field_value( 18 ); //pick up the value of the email field    
       //use the native function of wordpress to check if there's a user with this email 
       //is anyone has this email, it does not exist   
       if( !email_exists( $email )) {
                $ninja_forms_processing->add_error('email_no_existe', 'El email indicado no está registrado en nuestra base de datos'); //add_error stop the form and gives the error message                
        }
    }
}

With the code above everything works fine! :) Thanks!

Answer 2

Daniel,

I am not familiar with ninja_forms, but thinking of javascript, you can encapsulate your code to verify if users exists into an url and then, when making the ajax call, use it to verify... If you can't change the ajax request, you can validate the field on it's blur event and disable the submit button untill it's marked as "successfull"

For you to create PHP files, and yet, use all Wordpress power and functionalities, you can simply include this file on the beggining of the file that will be called require(wp-blog-header.php)