Request validation via jQuery, Json

Question

I want to do a function that the customer type his order it is checked if it exists in the bank or if it is an invalid request. And I want to return this via Ajax, but I never messed with Ajax, someone would know how to do?

Function

    public function verificaAction() {

            #Recebe o Pedido Postado
            $increment_id = $this->getRequest()->getParam('ordertxt');

            #Conecta banco de dados 
            $ordertexto = Mage::getModel('sales/order')->getCollection()->addAttributeToFilter('increment_id', $increment_id); 

            #Se o retorno for maior do que zero, envia o form, se for menor da o error
            if ($ordertexto[0]['increment_id'] == $increment_id) { 
            } else {
                echo json_encode(array('increment_id' => 'Número invalido' ));
    }
}

I don’t know where, but I think I’m doing some wrong check on IF.

jQuery Ajax try

$j("#ordertxt").focus(function() {}).blur(function() { 
    ordertxt = $j("#ordertxt").val(); 
         $j.ajax({ 
            url: '<?php echo Mage::getUrl('contato/index/verifica') ?>', 
            type: 'POST', 
            dataType: "json",
            success: function () {
            if (ordertexto == 1) {
                $j("#msg_pedido").html("Esse número de pedido não existe!");
            } else if (ordertexto == 0) {
                $j("#msg_pedido").html("Esse existe!");
            }
        },
    })
});

Answer 1

One of the mistakes you are making in your AJAX call is that you are not passing the value that was caught in the input $j("#ordertxt") through the date of the ajax

$.ajax({
 method: "POST",
 url: "some.php",
 **data: { name: "John", location: "Boston" }**
 dataType: 'json'
})

Another is that you are forgetting to pick up the return of your request through the Success Function parameter:

 success: function (result) 

You can try using this example below, maybe the return is not exactly as I put, because as you did not put the full if is difficult to know how will be treated the resutlad of this request, but you can give a console.log(data) and access the information in the best way, I believe that so you can get what you need

In the example below I am using a shorthand for Jquery AJAX

$j("#ordertxt").focus(function() {}).blur(function() { 
    ordertxt = $j("#ordertxt").val(); 
    
 // Enviando a data pelo post
var posting = $.post('<?= Mage::getUrl('contato/index/verifica') ?>', {'ordertxt': orderTxt }); 
  // verificando resultado
  // o parâmetro da função é o resultado retornado pela sua action
  posting.done(function( data ) {
      if(parseInt(data) === 1){
        $j("#msg_pedido").html("Esse número de pedido não existe!");
      } else if (parseInt(data) === 0) {
          $j("#msg_pedido").html("Esse existe!");
      }
  });
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

Oh and I believe it would be better if you use a GET instead of POST, since you just want to get information from the bank, this post explains better about HTTP verbs and when to use them