ajax成功响应后如何刷新div

Question

I have a form with ajax requests, when the fields are not respected and click on submit button the messages are displayed without page refresh. This works, the problem is that if the form is submitted several times, the error messages accumulate and multiple messages are displayed at the same time.

For example: if you leave field name blank and then submit, the error message (field required) appears. When you enter your name and then submit the success message (Settings Saved) appears but the error message is still visible.

What I want to get is only one message at a time, so the div should update showing the new message and deleting the previous one.

Now, I've tried doing some research and I understand that an if condition with $("#my-div").load("#my-div"); can be used in these cases but i have no idea how to do it, i am new to all this.

Can anyone help me understand how to achieve this? I appreciate any help and thank you for any replies.

My form

<form name="Form" class="mts-edit-account" action="<?php echo admin_url('admin-ajax.php'); ?>" method="post" enctype="multipart/form-data" <?php add_action( 'woocommerce_edit_account_form_tag', 'action_woocommerce_edit_account_form_tag' );?> > 
  
  <!-- Message section -->
  <div class="msg_box"></div>

  <!-- Fist & Last Name Field -->
  <div class="row name_surname">
    <div class="form-row">
      <label class="t3" for="account_first_name">Nome *</label>
      <input type="text" placeholder="Inserisci il tuo nome" class="field-settings" name="account_first_name" id="account_first_name" value="<?php echo esc_attr( $user->first_name ); ?>" />
    </div>

    <div class="form-row">
      <label class="t3" for="account_last_name">Cognome *</label>
      <input type="text" placeholder="Inserisci il tuo cognome" class="field-settings" name="account_last_name" id="account_last_name" value="<?php echo esc_attr( $user->last_name ); ?>" />
    </div> 

    <!-- Save Settings -->
    <p style="margin-bottom: 0px!important;">
      <?php wp_nonce_field( 'save_account_details', 'save-account-details-nonce' ); ?>
      <button type="submit" class="edit-account-button" name="save_account_details" value="<?php esc_attr_e( 'Save changes', 'woocommerce' ); ?>"><?php esc_html_e( 'Salva modifiche', 'woocommerce' ); ?></button>
      <input type="hidden" name="action" value="save_account_details" />
    </p>
  </div>
</form>

Script

jQuery(document).ready(function($) {
    
    $('.mts-edit-account').on('submit', function(e) { 
        e.preventDefault(); 

    //Ajax function
    jQuery.ajax({
      
      type: "post",
      data: jQuery(".mts-edit-account").serialize(),
      url: "wp-admin/admin-ajax.php",
      success : function( response ) {
        jQuery('.msg_box').append(response);  
      }

    });
    });
});

Functions.php

add_action( 'wp_ajax_save_account_details', 'save_account_details' );
add_action( 'woocommerce_save_account_details_errors','save_account_details', 10, 1 );
function save_account_details() {

  if (trim($_POST['account_first_name']) == '') {
    $response = wc_print_notices( $return = false );
  } else {
    $response = "Settings Saved!";
  }

  // Don't forget to exit at the end of processing
  echo json_encode($response);
  exit();

}

Answer 1

You've used jQuery('.msg_box').append(response) method for displaying the messages. The documentation clearly states that this is used to insert content, specified by the parameter, to the end of each element in the set of matched elements.

Naturally giving you the multiple messages. If you just need a single message, then use:

jQuery('.msg_box').html(response)

.html() will ensure that the content of the container is overridden each time.

Reference: Official Documentation