Contactform7 prevent duplicate field value submission

Question

I am using WordPress 3.8 and contact form 7 plugin with contact form 7 db extension.

I want to check for existing email which I do on submit on a hook (alter_wpcf7_posted_data) in functions.php as below:

function alter_wpcf7_posted_data( $data ) {

    global $wpcf7;

    if(email_exists( $_POST['mail'])) {
            $data = array();
    }

return $data;
}
add_filter("wpcf7_posted_data", "alter_wpcf7_posted_data");

This hook throws me an error on the source but does not save data.

Basically, I wish not to save the data and throw a validation error on the form if email_exists() returns true.

Does anyone know how to prevent form submission.

Note: I am not using an AJAX form submission.

Answer 1

I find solution for this. Just add this code in your function.php

/**
 * @param $formName string
 * @param $fieldName string
 * @param $fieldValue string
 * @return bool
 */
function is_already_submitted($formName, $fieldName, $fieldValue) {
    require_once(ABSPATH . 'wp-content/plugins/contact-form-7-to-database-extension/CFDBFormIterator.php');
    $exp = new CFDBFormIterator();
    $atts = array();
    $atts['show'] = $fieldName;
    $atts['filter'] = "$fieldName=$fieldValue";
    $atts['unbuffered'] = 'true';
    $exp->export($formName, $atts);
    $found = false;
    while ($row = $exp->nextRow()) {
        $found = true;
    }
    return $found;
}

/**
 * @param $result WPCF7_Validation
 * @param $tag array
 * @return WPCF7_Validation
 */
function my_validate_email($result, $tag) {
    $formName = 'email_form'; // Change to name of the form containing this field
    $fieldName = 'email_123'; // Change to your form's unique field name
    $errorMessage = 'Email has already been submitted'; // Change to your error message
    $name = $tag['name'];
    if ($name == $fieldName) {
        if (is_already_submitted($formName, $fieldName, $_POST[$name])) {
            $result->invalidate($tag, $errorMessage);
        }
    }
    return $result;
}

// use the next line if your field is a **required email** field on your form
add_filter('wpcf7_validate_email*', 'my_validate_email', 10, 2);
// use the next line if your field is an **email** field not required on your form
add_filter('wpcf7_validate_email', 'my_validate_email', 10, 2);

// use the next line if your field is a **required text** field
add_filter('wpcf7_validate_text*', 'my_validate_email', 10, 2);
// use the next line if your field is a **text** field field not required on your form 
add_filter('wpcf7_validate_text', 'my_validate_email', 10, 2);

remember to change email_form with your contact form name and email_123 with email field name. Work just fine for me with WordPress 4.9.5 and CF7 5.0.1

Answer 2

I have tried many solutions but many not working with me finally decide to change button content and backgroup-color for 10 second (or whatever you need)

have to set ID for submit button

[submit id:SendFormDataM "send your request"]

they use this jquery code (I have added it in jquery.jvcf7_validation.js file)

function submitPoll(){
document.getElementById("SendFormDataM").style.backgroundColor = "#000000";
document.getElementById("SendFormDataM").value="please waiting";
setTimeout(function() {
    document.getElementById("SendFormDataM").style.backgroundColor = "#bc8a49";
    document.getElementById("SendFormDataM").value="send your request";
}, 10000);

}
var el = document.getElementById("SendFormDataM"); // use this if you have multi ID's
if(el){
      el.addEventListener('click', submitPoll);
}

this will change background-color to black and write "please wait"

after 10 seconds, the button will be back to the normal background-color with old content

I have tried disabled the button, but its didn't send form data

Answer 3

After a long time trying to find a functional code that can be used independently of the plugin that saves contacts in the database, I came up with the code below.

/*We created the filter*/
add_filter( 'wpcf7_validate', 'email_already_in_db', 10, 2 );

/*We created the function*/
function email_already_in_db ( $result, $tags ) {

// We take the information from the form being submitted
$form = WPCF7_Submission::get_instance(); /*Here is the form ID of the Contact Form*/
$email = $form->get_posted_data('email'); /*Here is the email field*/

date_default_timezone_set('America/Sao_Paulo'); /*We set the time zone*/
$datetoday = date("Y-m-d"); /*We take the current date in the format that the contact plugin records the date*/

global $wpdb;
/*We make a select in the table where the contacts are recorded, checking if the email informed already exists on today's date */
$entry = $wpdb->get_results( "SELECT * FROM wp_db7_forms WHERE form_value LIKE '%$email%' AND form_date LIKE '%$datetoday%'" );

// If the select query in the database is positive (the email exists on the current date), it returns the error in the form, in the email field, not sending
if (!empty($entry)) {
$result->invalidate('email', 'Email already exists');
}

return $result;
}

I built my version based on: https://www.stacknoob.com/s/6X5Lisxm3DE87aGby3NzQZ

Answer 4

I Created my own solution of the question.. Just replace the DB_PREFIX and FORM_ID according to your form ...Check it and I hope this will help you

function is_already_submitted($formPostId, $fieldName, $fieldValue) {

    global $wpdb;

    /*We make a select in the table where the contacts are recorded, checking if the email informed already exists on today's date */

    $entry = $wpdb->get_results( "SELECT * FROM DB_PREFIX_db7_forms WHERE form_value LIKE '%$fieldValue%' AND form_post_id = '$formPostId'" );
    
    // If the select query in the database is positive (the email exists on the current date), it returns the error in the form, in the email field, not sending

    $found = false;
    if (!empty($entry)) {
        $found = true;
    }
    return $found;
}

function my_validate_email($result, $tag) {
    $formPostId = 'FORM_ID'; // Change to name of the form containing this field
    $fieldName = 'your-email'; // Change to your form's unique field name
    $errorMessage = 'This email address is already registered'; // Change to your error message
    $name = $tag['name'];
    if ($name == $fieldName) {
        if (is_already_submitted($formPostId, $fieldName, $_POST[$name])) {
            $result->invalidate($tag, $errorMessage);
        }
    }
    return $result;
}

add_filter('wpcf7_validate_email*', 'my_validate_email', 10, 2);

Answer 5

Pay attention to related CF7 plugins. In my case the duplicate form submission was caused by Jquery Validation For Contact Form 7.