Questions on passing and formatting JSON to HttpResponse

Question

I just wanted to clarify a few questions I have. I'm building a JSON string and returning it using context.response. I'm just calling a url to an .ashx handler and trying to return JSON.

Here's how I have approached it so far:

List products = GetCarolProducts(); List images = new List();

foreach(Product p in products)
{

    string imageTag = string.Format(@"<img src=""{0}"" alt=""""></li>", Util.ImageUrl(p.Image, false));

    images.Add(imageTag);
    i++;
}

string jsonString = images.ToJSON();
context.Response.Write(jsonString);

I'm using the example helper method here for the JSON: http://weblogs.asp.net/scottgu/archive/2007/10/01/tip-trick-building-a-tojson-extension-method-using-net-3-5.aspx

So my questions are:

1) I didn't want to pass back the entire product object. In fact I didn't want to pass that back at all. I wanted to pass back a bunch of image tags that I made in my foreach loop. so what I did was just create that string in each iteration of product and added it to a new generic list of type string. I assume this is fine, and that passing a generic string list can be serialized into JSON...that string is an object itself so this should be fine? thing is, it's not going to have any properties so I don't know. I guess I would be leary if this is going to work as if I were to pass an object such as product for example, it at least has properties in it such as ID, Name, etc.

So if this is not going to work, I am wondering how I can just receive back a list of JSON that gives me . I believe though I still need to be able to access that returned JSON with key/value though. But in terms of data, that's all I need in my jQuery, just a bunch of images.

So therefore my question is, m**ust I pass an object that has properties in it so that my returned JSON has some params I can picked up via the jQuery since jQuery creates a nice typed object for you based on those properties?** I don't think sending a generic string list would work in my situation then.

so not quite sure how to set this up and pass only the list of images to my ToJSON helper method and ultimately to my jQuery JSON parsing.

2) Not sure if I need to do anything special to tell the context.response that it's JSON other than pass it the final string that the helper method here creates? with XML you'd have to tell the response to format it as XML with context .Response .ContentType = "text/xml". So do I need to specify anything if I'm passing back JSON strings?

Answer 1

For the response content-type, look at Douglas Crockford's JSONRequest proposal.

Content-Type: application/jsonrequest