在自动完成中添加最后一个提取词的邮件验证

Question

我有一个带有自动完成选项的textarea，用于邮件ID，我想检查邮件ID的最后提取术语的有效性。我想在输入符号逗号'，'之后进行验证。此textarea允许键入并自动完成邮件ID。 我想知道在自动完成代码中的何处添加验证代码

$( function() {
function split( val ) {
  return val.split( /,\s*/ );
}
function extractLast( term ) {
  return split( term ).pop();
}

$( "#mail_receipient" )
  // don't navigate away from the field on tab when selecting an item
  .bind( "keydown", function( event ) {
    if ( event.keyCode === $.ui.keyCode.TAB &&
        $( this ).autocomplete( "instance" ).menu.active ) {
        event.preventDefault();
    }
  }).autocomplete({ 
     minLength: 3,
    appendTo: "#myModal",
    source:function( request, response ) {
      $.getJSON( "search/autocomplete", {
        term: extractLast( request.term )
    }, response );},
    focus: function() {
      // prevent value inserted on focus
      return false;
    },
    autoFocus:true,
    select: function( event, ui ) {
      var terms = split( this.value );
      // remove the current input
      terms.pop();
      // add the selected item
      terms.push( ui.item.value );
      // add placeholder to get the comma-and-space at the end
      terms.push( "" );
      this.value = terms.join( ", " );
      return false;
    } });
 } );



var testEmail = /^[A-Z0-9._%+-]+@([A-Z0-9-]+\.)+[A-Z]{2,4}$/i;
    if (testEmail.test(term)) alert('passed'); //in last extract after typing', '
    else alert('failed');