Question

The below way I call my pageload function by jQuery.

Please tell me how to pass query string.

<script type="text/javascript" src="script/jquery-1.3.2.min.js"></script>

<script type="text/javascript">
  $(document).ready(function() {
    $('#Customers').change(function() {
      $.ajax({
        contentType: "text/html; charset=utf-8",
        data: "CustomerID=" + $('#Customers').val(),
        url: "FetchCustomer.aspx",
        dataType: "html",
        success: function(data) {
          $("#CustomerDetails").html(data);
        }
      });
    });
  });
</script>

I have a few questions like

1. when type: “POST”, then contentType: “application/json; charset=utf-8”,
   has to be application/json? it can not be html?

2. when type: “POST” then url can’t be like url: “Customer.aspx?ID=101/FetchCustomer”
   I mean I can not then pass query string.

Guide me please. Thanks

Answer 1

GET and POST has nothing to do with contentType you can set contentType:"html" with type:"POST"

when you set the type:"POST" the form values are not visible in the query string like www.utopia.com?name=john&lastName=smith

The HTML specifications technically define the difference between "GET" and "POST" so that


former means that form data is to be encoded (by a browser) into a URL while the latter means that 

the form data is to appear within a message body. But the specifications also give the usage 

recommendation that the "GET" method should be used when the form processing is "idempotent", and in

 those cases only. As a simplification, we might say that "GET" is basically for just getting 

(retrieving) data whereas "POST" may involve anything, like storing or updating data, or ordering a 

product, or sending E-mail.

REF: http://www.cs.tut.fi/~jkorpela/forms/methods.html#fund

  $(document).ready(function() {
    $('#Customers').change(function() {
      $.ajax({
        type:'POST',
        contentType: "text/html; charset=utf-8",
        data:{CustomerID:$('#Customers').val()},
        url: "FetchCustomer.aspx",
        dataType: "html",
        success: function(data) {
          $("#CustomerDetails").html(data);
        }
      });
    });
  });