My service setup isn't exactly the same as yours but I think the same
solution will work for you.
You'll need to add two classes, one that inherits from Stream (we'll
call is JsonStream) and another that inherits from the IHttpModule
interface (we'll call this JsonModule). The JsonStream class will
need a public property to store the name of the callback (e.g.
CallbackFunctionName).
JsonModule's Init needs to first look for all RequestType = GET and,
for all such requests, do a GetValues on "callback" to see if the
caller expects us to make a callback or simply return data. If a
callback param is present we need to create a new instance of
JsonStream passing the current context's Response.Filter to the
constructor and then set CallbackFunctionName to the appropriate
value. Then, in JsonStream in the overridden Write method, if
CallbackFunctionName has a value you need to do something like (where
_stream is the value passed into JsonStream's constructor):
string content = CallbackFunctionName + "(" +
Encoding.UTF8.GetString(bugger) + ");";
_stream.Write(Encoding.UTF8.GetBytes(content), 0, content.Length);
In this way you've decoupled the callback functionality from your WCF
service(s) but it "just works" for cases that require it. Hopefully
this implementation will work in your scenario.
On Oct 24, 9:22 am, RWF <[EMAIL PROTECTED]> wrote:
> Thanks for the info. How exactly are you writing directly to the
> response using WCF? My IIS hosted WCF service is basically just
> acting like a proxy to a windows hosted WCF service, so they both use
> the same contract, but the IIS hosted service is a REST based
> service. Is there a way to maintain this uniformity of contracts,
> while writing directly to the response of the IIS service?
>
> On Oct 23, 8:22 am, tenaciousd <[EMAIL PROTECTED]> wrote:
>
> > If you're going to do cross-domain calls you can't do a POST, only a
> > GET. I think even if you specify POST as your type jQuery will
> > convert it to a GET if your datatype is jsonp (check their doc but I'm
> > pretty sure that's the case).
>
> > As for WCF the key is just making sure that you wrap your return in
> > the callback method and write it to the Response. In other words, you
> > can't simply have a WCF endpoint that returns a json-formatted
> > object. Instead you need to write something like
> > "callbackMethodName(" + yourJSONObject + ");" to the Response. Once
> > you've done this jQuery will execute the callback call, in which it
> > will do an eval() on yourJSONObject and then call the success method,
> > passing it the JSON object in the data parameter. At that point you
> > will have dot notation on your JSON object.
>
> > On Oct 22, 7:31 pm, RWF <[EMAIL PROTECTED]> wrote:
>
> > > I am using WCF too, have you done projects that require an $.ajax POST
> > > request to a WCF service cross site? If you have, how did come up
> > > with a server proxy to allow for cross site communication?
>
> > > On Oct 10, 2:01 pm, tenaciousd <[EMAIL PROTECTED]> wrote:
>
> > > > Nevermind. The fundamental issue was that the json object wrapped in
> > > > the callback name does, in fact, need to be written to the Response.
> > > > I'm an idiot. Anyway, it's working now. If others hit the same
> > > > jquery ->jsonp-> wcf issue let me know.
>
> > > > On Oct 10, 12:07 pm, tenaciousd <[EMAIL PROTECTED]> wrote:
>
> > > > > I'm using jQuery $.ajax to make a cross-domainjsonpcall to a WCF
> > > > > service. The call is working fine, entering the service endpoint, but
> > > > > the callback method never fires. I've tried many permutations of
> > > > > changes and can't seem to get this to work.
>
> > > > > The WCF endpoint is returning a string (NOT doing a Response.Write)
> > > > > that contains a json object inside the callback wrapper (e.g.
> > > > > "jsonp123( {"Author":"John Doe","Price":"$35.90"} )" ) and the
> > > > > content-
> > > > > type returned from the service is application/json; charset=utf-8.
>
> > > > > $.ajax call is below. Any help is much appreciated.
>
> > > > > var data = {"ISBN" : $("#isbn1").val()};
>
> > > > > $.ajax({
> > > > > type: "GET",
> > > > > cache: false,
> > > > > url:
> > > > > "http://localhost:63132/Widget.svc/GetProductInfo";,
> > > > > scriptCharset: "utf-8",
> > > > > dataType: "jsonp",
> > > > > data: data,
> > > > > success: function(data, textStatus){
> > > > > alert("success");
> > > > > },
> > > > > error: function(XMLHttpRequest, textStatus,
> > > > > errorThrown){
> > > > > alert('error');
> > > > > }
> > > > > });
