How do I build a JSON object to send to an AJAX WebService?

Question

After trying to format my JSON data by hand in javascript and failing miserably, I realized there's probably a better way. Here's what the code for the web service method and relevant classes looks like in C#:

[WebMethod]
public Response ValidateAddress(Request request)
{
    return new test_AddressValidation().GenerateResponse(
        test_AddressValidation.ResponseType.Ambiguous);
}

...

public class Request
{
    public Address Address;
}

public class Address
{
    public string Address1;
    public string Address2;
    public string City;
    public string State;
    public string Zip;
    public AddressClassification AddressClassification;
}

public class AddressClassification
{
    public int Code;
    public string Description;
}

The web service works great with using SOAP/XML, but I can't seem to get a valid response using javascript and jQuery because the message I get back from the server has a problem with my hand-coded JSON.

I can't use the jQuery getJSON function because the request requires HTTP POST, so I'm using the lower-level ajax function instead:

$.ajax({
    type: "POST",
    contentType: "application/json; charset=utf-8",
    url: "http://bmccorm-xp/HBUpsAddressValidation/AddressValidation.asmx/ValidateAddress",
    data: "{\"Address\":{\"Address1\":\"123 Main Street\",\"Address2\":null,\"City\":\"New York\",\"State\":\"NY\",\"Zip\":\"10000\",\"AddressClassification\":null}}",
    dataType: "json",
    success: function(response){
        alert(response);
    }
})

The ajax function is submitting everything specified in data:, which is where my problem is. How do I build a properly formatted JSON object in javascript so I can plug it in to my ajax call like so:

data: theRequest

I'll eventually be pulling data out of text inputs in forms, but for now hard-coded test data is fine.

How do I build a properly formatted JSON object to send to the web service?

---

UPDATE: It turns out that the problem with my request wasn't the formatting of the JSON, as T.J. pointed out, but rather that my JSON text didn't conform to requirements of the web service. Here's a valid JSON request based on the code in the WebMethod:

'{"request":{"Address":{"Address1":"123 Main Street","Address2":"suite 20","City":"New York","State":"NY","Zip":"10000","AddressClassification":null}}}'

This brought up another question: When is case sensitivity important in JSON requests to ASP.NET web services (ASMX)?

Answer 1

JSON.stringify will take a javascript object and turn it into a string. I bet though that if you create a Javascript object like

var jsonData = {
    address: 'address',
    address1: 'address1',
    address2: 'address2'
};

and then pass in jsonData as 'data' in the ajax call, then it will convert the object to json text for you.

Answer 2

Get yourself a jquery plugin that can convert any javascript object to json. For example:

http://plugins.jquery.com/project/json

Answer 3

I would create a javascript object and then call JSON.stringify to turn it into valid JSON. You can download it from here.

You could do something like this:

var address= {};

address["Address1"] = "your val";
address["Address2"] = "your val";
address["City"] = "your val";
address["State"] = "your val";
address["Zip"] = "your val";

$.ajax({
    type: "POST",
    contentType: "application/json; charset=utf-8",
    url: "http://bmccorm-xp/HBUpsAddressValidation/AddressValidation.asmx/ValidateAddress",
    data: JSON.stringify(address),
    dataType: "json",
    success: function(response){
        alert(response);
    }
});

Answer 4

You need to pass it like this:

$.ajax({
  type: "POST",
  url: "WebService.asmx/WebMethodName",
  data: "{'fname':'dave', 'lname':'ward'}",
  contentType: "application/json; charset=utf-8",
  dataType: "json"
});

Have a look at this article for more details: 3 mistakes to avoid when using jQuery with ASP.NET AJAX

Answer 5

All apologies if this answer comes too late, or is a duplication.

From what I understand, it appears as though you're trying to send just the string of a JSON object. Try building an object and then working with its properties and sending it in as it is.

Example:

address = new Object();
address.Address = new Object();
address.Address.Address1 = "123 Main Street";
address.Address.Address2 = "";
address.Address.City = "New York";
address.Address.State = "NY";
address.Address.Zip = "10000";
address.Address.AddressClassification = null;
$.ajax({
    type: "POST",
    contentType: "application/json; charset=utf-8",
    url: "http://bmccorm-xp/HBUpsAddressValidation/AddressValidation.asmx/ValidateAddress",
    data: address,
    dataType: "json",
    success: function(response){
        alert(response);
    }
});

Answer 6

Your problem breaks down into two parts:

Creating the JSON string

Your JSON in your quoted code is perfectly valid. But being hand-crafted is a pain. As others have called out, the easiest way to do this is to create a Javascript object and then JSON.stringify it. Example:

var data = {
    "Address": {
        "Address1": "123 Main Street",
        "Address2": null,
        "City": "New York",
        "State": "NY",
        "Zip": "10000",
        "AddressClassification": null
    }
};
data = JSON.stringify(data);

The first step above creates an object using Javascript object literal notation, which is a superset of JSON (as used above, it actually is the same as JSON, but ignore that). The second bit takes that object and converts it to a string.

Of course, the values above are literal strings, which is unlikely. Here's what it would look like if you had each of those values in a variable:

var data = {
    "Address": {
        "Address1": address1,
        "Address2": address2,
        "City": city,
        "State": state,
        "Zip": zip,
        "AddressClassification": null
    }
};
data = JSON.stringify(data);

Either way, now you have the string.

Sending the JSON string to the web service

You need to find out is whether the web service is expecting the JSON-formatted data to be the POST body, or if it's expecting the JSON data to be the value of a parameter in the more common name=value URL-encoded POST data. I would tend to expect the former, because the web service seems specifically designed to work with JSON-formatted data.

If it's supposed to be the POST body, well, I've never done that with jQuery, and what you have quoted looks correct to me reading the docs. If it's not working, I'd double-check that your object structure is really what they're expecting to see. For instance, if it's just validating a single address, I wonder if it's expecting to receive just an Address object, rather than an object containing an Address object, e.g.:

{
    "Address1": "123 Main Street",
    "Address2": null,
    "City": "New York",
    "State": "NY",
    "Zip": "10000",
    "AddressClassification": null
}

If it's supposed to be the value of a parameter in boring old URL-encoded multipart form data, then:

$.ajax({
    type: "POST",
    url: "http://bmccorm-xp/HBUpsAddressValidation/AddressValidation.asmx/ValidateAddress",
    data: "paramname=" + encodeURIComponent(data),
    dataType: "json",
    success: function(response){
        alert(response);
    }
})

I've removed the contentType so jQuery will fall back to its default ("application/x-www-form-urlencoded") and ensured the string we created above is properly encoded in that content type. You'll need to find out the paramname to use (perhaps "Address" and see my earlier comment about sending just the address, rather than an object containing an address child object?).

Answer 7

The answer is very easy and based on my previous posts http://stackoverflow.com/questions/2670147/can-i-return-json-from-an-asmx-web-service-if-the-contenttype-is-not-json/2671583#2671583 and http://stackoverflow.com/questions/2651091/jquery-ajax-call-to-httpget-webmethod-c-not-working/2656543#2656543.

The data should be JSON-encoded. You should separate encode every input parameter. Because you have only one parameter you should do like following:

first construct you data as native JavaScript data like:

var myData = {Address: {Address1:"address data 1",
                        Address2:"address data 2",
                        City: "Bonn",
                        State: "NRW",
                        Zip: "53353",
                        {Code: 123,
                         Description: "bla bla"}}};

then give as a parameter of ajax request {request:$.toJSON(myData)}

$.ajax({
    type: "POST",
    contentType: "application/json; charset=utf-8",
    url: "http://bmccorm-xp/HBUpsAddressValidation/AddressValidation.asmx/ValidateAddress",
    data: {request:$.toJSON(myData)},
    dataType: "json",
    success: function(response){
        alert(response);
    }
})

instead of $.toJSON which come from the JSON plugin you can use another version (JSON.stringify) from http://www.json.org/

If your WebMethod had parameters like

public Response ValidateAddress(Request request1, Request myRequest2)

the value of data parameter of the ajax call should be like

data: {request1:$.toJSON(myData1), myRequest2:$.toJSON(myData2)}

or

data: {request1:JSON.stringify(myData1), myRequest2:JSON.stringify(myData2)}

if you prefer another version of JSON encoder.