i have a mail feature in wordpress admin plugin and i want the ability to attach a file dynamically and send it through mail as an attachment. i using ajax method but i did not know how to send input file through ajax This is html code
<div class="kids-top-right-view">
  <ul class="kids-list kids-list-inline kids-nav-item">
        <li>
          <a>
              <i class="fa fa-envelope-o"></i> Email</a>
      </li>
    </ul>
    <div class="note_container">
      <form method="post" id="mail_parent_form" enctype="multipart/form-data">
        <input type="hidden" name="action" value="attach_file_parent">
        <p class="email-from">
            <label>From</label>
            <span class="sep">:</span>
            <span class="value">Casting Kids(office@castingkids.com.au)</span>
        </p>
        <p class="email-to">
            <label>To</label>
            <span class="sep">:</span>
            <span class="value"><?=$child[0]->fname.' '.$child[0]->lname?></span>
            <input type="hidden" class="email_address" value="<?=$child[0]->email?>">
        </p>
        <p class="email-subject">
            <label>Subject</label>
            <span class="sep">:</span>
            <span class="value">
                <input type="text" name="email_subject" placeholder="Subject...">
            </span>
        </p>
        <div id="parent_mail">
          <trix-editor placeholder="Type your email body ....."></trix-editor>
          <div class="client-action">
      <input type="submit" class="button button-primary" id="email_P" name="email_parent" value="Send Mail" >
      <input type="file" name="file[]" id="email_file" multiple>
      <label for="email_file">Attach File</label>
      <input type="reset" class="button button-default" value="Discard">
      <p style="display: none;" class="error_message"></p>
      <p style="display: none;" class="success_message"></p>
  </div>
        </div>
    </form>
  </div>
</div>
Jquery Code
$("#email_file").on('change',function(){
  var input = document.getElementById('email_file');
  var files = input.files;
  data = {'action':'attach_file_parent','files':files};
  jQuery.post(ajaxurl, data, function(response) {
  })
})
But it gives me this error: Illegal Invocation beacause i dont know where to add this line processData: false to tackle this error and i have to use this method for ajax. i cant be able to use this
$.ajax({
    url  : ajaxurl,
    type : 'POST',
    data : formData,
    contentType: false,
    processData: false
}) 
as it gives me ajax not found error Please suggest me with this, thank you
 
     
    