RFC on HttpWebRequest vs RESTSharp from Windows CE / Compact Framework 3.5

Question

I created a simple WebAPI service in .NET4 and Visual Studio 2010.

I need to consume that service in a Windows CE / CF 3.5 app

I do have HttpWebRequest available to me, but am not sure if this is the way to go, or I should use RestSharp. Does anybody have insight/experience that would help me decide? I prefer not using 3rd party code when possible to avoid it, but am willing to do so if there is a clear advantage over the "raw" offerings.

Does anyone have, or know of, examples for accessing WebApi services using HttpWebRequest OR RestSharp from CF 3.5?

I have this code (adapted from from http://www.asp.net/web-api/overview/getting-started-with-aspnet-web-api/tutorial-your-first-web-api) for sample WebAPI methods:

public class VendorItemsController : ApiController
{
    VendorItem[] vendorItems = new VendorItem[] 
    {   
        new VendorItem { VendorId = "1", VendorItemId = "Tomato Soup", ItemId = "Groceries", PackSize = 1 }, 
        new VendorItem { VendorId = "2", VendorItemId = "V8", ItemId = "Groceries", PackSize = 6 }, 
        new VendorItem { VendorId = "3", VendorItemId = "Garlic", ItemId = "Groceries", PackSize = 1 }, 
    };

    public IEnumerable<VendorItem> GetAllProducts()
    {
        return vendorItems;
    }

    public VendorItem GetProductById(string id)
    {
        var vendorItem = vendorItems.FirstOrDefault((p) => p.VendorId == id);
        if (vendorItem == null)
        {
            throw new HttpResponseException(HttpStatusCode.NotFound);
        }
        return vendorItem;
    }
}

...but don't know how to consume this using, if possible, HttpWebRequest.

Note: HttpClient is not available to me (HttpWebRequest is, though).

UPDATE

I start the VS2010 app that has the WebAPI method; but when I run the VS2008 Windows CE / Compact Framekwork 3.5 app with this code:

Uri _baseAddress = new Uri("http://localhost:48614/");
string localFile = "fetchedVendorItems.txt";
HttpWebRequest req = (HttpWebRequest)WebRequest.Create(_baseAddress + "api/vendoritems/");
req.Method = "GET";
HttpWebResponse resp = (HttpWebResponse) req.GetResponse();

// Retrieve response stream and wrap in StreamReader
Stream respStream = resp.GetResponseStream();
StreamReader rdr = new StreamReader(respStream);

// Create the local file
StreamWriter wrtr = new StreamWriter(localFile);

// loop through response stream reading each line and writing to the local file
string inLine = rdr.ReadLine();
while (inLine != null)
{
    wrtr.WriteLine(inLine);
    inLine = rdr.ReadLine();
}

rdr.Close();
wrtr.Close();

(which I adapted from here: http://msdn.microsoft.com/en-us/library/aa446517.aspx)

...I get, "Unable to connect to the remote server"

UPDATE 2

This does work directly in the browser on the dev machine:

http://localhost:48614/api/redemptions/

It returns these values from a Controller:

readonly Redemption[] redemptions =
{   
    new Redemption { RedemptionId = "1", RedemptionName = "Old", RedemptionItemId = "ABC", RedemptionAmount = 0.25M, RedemptionDept = "2.0", RedemptionSubDept = "42" }, 
    new Redemption { RedemptionId = "2", RedemptionName = "Damaged", RedemptionItemId = "BCD", RedemptionAmount = 5.00M, RedemptionDept = "42.0", RedemptionSubDept = "76" }, 
    new Redemption { RedemptionId = "3", RedemptionName = "Rebate", RedemptionItemId = "DEF", RedemptionAmount = 42.75M, RedemptionDept = "76.0", RedemptionSubDept = "112" }
};

...like so:

<ArrayOfRedemption xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://schemas.datacontract.org/2004/07/HHSServerWebAPI.Models">
<Redemption>
<RedemptionAmount>0.25</RedemptionAmount>
<RedemptionDept>2.0</RedemptionDept>
<RedemptionId>1</RedemptionId>
<RedemptionItemId>ABC</RedemptionItemId>
<RedemptionName>Old</RedemptionName>
<RedemptionSubDept>42</RedemptionSubDept>
</Redemption>
<Redemption>
<RedemptionAmount>5.00</RedemptionAmount>
<RedemptionDept>42.0</RedemptionDept>
<RedemptionId>2</RedemptionId>
<RedemptionItemId>BCD</RedemptionItemId>
<RedemptionName>Damaged</RedemptionName>
<RedemptionSubDept>76</RedemptionSubDept>
</Redemption>
<Redemption>
<RedemptionAmount>42.75</RedemptionAmount>
<RedemptionDept>76.0</RedemptionDept>
<RedemptionId>3</RedemptionId>
<RedemptionItemId>DEF</RedemptionItemId>
<RedemptionName>Rebate</RedemptionName>
<RedemptionSubDept>112</RedemptionSubDept>
</Redemption>
</ArrayOfRedemption>

...even when the VS2008 project is not running - is that because this data was cached (the first time I entered:

http://localhost:48614/api/redemptions/

...in the browser, the Web API app was running)?

I get that the emulator won't recognize "localhost" as the desktop instance, considering itself someone/somewhere else. So how can I test this on an emulator? What IP address can I use?

Answer 1

Avoiding 3rd party code out of hand is just plain silly. Why reinvent the wheel? If you are a company who's IP is making REST calls, then sure, roll it, but I suspect your core business offering is in solving some other problem. I mean why use the CF itself, and not C? Why use C and not assembly? Why use a third-party processor and not design your own?

All that aside, RestSharp comes with source and it's free, so there's little risk in using it. There are some things I like about it - primarily that most of the grunt work for REST calls done. I'm a big fan of not reinventing things. It has some quirks that I've "fixed" locally (I'm meaning to do a pull request, just haven't found the time yet) but they were minor and not what I'd consider to be "typical" cases.

As for calling Web APIs with RestSharp, there's a pretty thorough coverage over in this article.