Can't consume ASP.NET Web Service from jQuery - asp.net

Question

Here's an interesting problem:
I have some jQuery that looks like this:
$(document).ready(function() {
$.ajax({
type: "POST",
url: "http://localhost:63056/Service1.asmx/PrintOrderRecieptXml",
data: {
"CouponCode": "TESTCODE",
"Subtotal": 14.2600,
"ShippingTotal": 7.5000,
"TaxTotal": 0.0000,
"GrandTotal": 21.7600,
"OrderItemCollection": [{
"Total": 14.2600,
"Qty": 250
}]
},
dataType: "json",
contentType: "application/json",
error: function(xhr, msg) {
alert(xhr.statusText);
}
});
});
Now, the problem I'm having is that it's sending the request, but the web service isn't processing it correctly. In IE, I get an alert box with "Internal Server Error" and with FireFox I get an alert box with nothing in it.
The strange thing is that when I use IE, I do not get an error event in my event log, but with firefox I get (bonus points for figuring out why this is):
"Exception message: Request format is unrecognized for URL unexpectedly ending in '/PrintOrderRecieptXml"
I poked around some and found out that sometimes you have to add:
<webServices>
<protocols>
<add name="HttpGet"/>
<add name="HttpPost" />
<add name="HttpPostLocalhost"/>
</protocols>
</webServices>
To your Web.Config, which I did but it did not help. The interesting thing is that the web service works fine with SOAP or sending a query string, but not with JSON.
Any ideas?

Answer 1

You need to give your input to the data property as a JSON string, not as an object:
$(document).ready(function() {
$.ajax({
type: "POST",
url: "http://localhost:63056/Service1.asmx/PrintOrderRecieptXml",
data: '{"CouponCode":"TESTCODE","Subtotal":14.2600,"ShippingTotal":7.5000,"TaxTotal":0.0000,"GrandTotal":21.7600,"OrderItemCollection":[{"Total":14.2600,"Qty":250}]}',
dataType: "json",
contentType: "application/json",
error: function(xhr, msg) {
alert(xhr.statusText);
}
});
});
Using jQuery to Consume ASP.NET JSON Web Services has a good explanation of the requirements when talking to ASP.Net Web Services.

Answer 2

Douglas is correct - you need to format the data as a string. Be sure to read all of the posts on the blog that he linked you to. Encosia is a great resource for Ajax and Asp.Net.

Answer 3

asp.net webservices don't return json normally. take a look here:
JSON WebService in ASP.NET