I'm done banging my head on the keyboard for this one.
I have a WCF client project that can be used to hit the Yahoo GeoPlanet service. One of their endpoints for free-text querying can be represented like so:
[OperationContract(Name = "places")]
[WebGet(
UriTemplate = "places.q({query});count=0?format=json&view={view}&appid={appId}",
RequestFormat = WebMessageFormat.Json,
ResponseFormat = WebMessageFormat.Json,
BodyStyle = WebMessageBodyStyle.Bare
)]
PlacesResponse Places(string query, string appId, RequestView view);
There is an implementation of this that invokes the WCF client (more or less) like so: (there is retry logic here, but this is what it boils down to)
public Places Places(string query, string appId, RequestView view = RequestView.Long)
{
return Channel.Places(HttpUtility.UrlEncode(query), appId, view);
}
The problem is that, even though the query
parameter is url encoded, by the time WCF issues the actual HTTP request, values of %2F
are converted back into a forward slash (/
). As a result, searches like "Saint Augustine Tunapuna/Piarco, Trinidad and Tobago"
are (understandably) being rejected with a 400 Bad Request by the Yahoo server.
The worst part of it is that this only seems to happen when the client library is used as a non-visual studio project reference. I have the following test in the project, which always passes:
[TestMethod]
public void Yahoo_GeoPlanet_GeoPlanetClient_Places_ShouldUrlEncodeQuery_WhenItContainsUnsafeCharacters()
{
using (var geoPlanetClient = new GeoPlanetClient())
{
var places = geoPlanetClient.Places("Saint Augustine Tunapuna/Piarco, Trinidad and Tobago", AppId);
places.ShouldNotBeNull();
places.Items.Count.ShouldBeInRange(1, int.MaxValue);
}
}
When I use this library in another project, it works only when the client .csproj is part of the other project's solution, and is referenced as a project reference. As soon as I include it as a NuGet package or direct dll file reference, it fails.
I have stepped down into the code, and it seems like the URL is correctly encoded by the time it is passed to the Channel
. However sometime after that, the %2F
in the search string is getting converted back into a forward slash. The only reason I know this is from inspecting the request in fiddler.
Perhaps consider using
HttpClient
? It's a LOT simpler.