WebGet UriTemplate fails on dot ('.'/%2E)? - wcf

I've been trying for a while now to figure out why this UriTemplate does not work as part of a WCF service and can't seem to get anywhere:
[WebGet(UriTemplate="api/1.0/version")]
string GetVersion();
A quick test shows that UrlTemplateTable matches it fine (output is 'api/1.0/version'):
static void Main(string[] args)
{
Uri prefix = new Uri("http://localhost/");
System.UriTemplateTable table = new System.UriTemplateTable(prefix);
table.KeyValuePairs.Add(new KeyValuePair<UriTemplate, Object>(new UriTemplate("api/1.0/version"), "a"));
table.KeyValuePairs.Add(new KeyValuePair<UriTemplate, Object>(new UriTemplate("api/2.0/version"), "b"));
table.KeyValuePairs.Add(new KeyValuePair<UriTemplate, Object>(new UriTemplate("api/version"), "c"));
Uri uri = new Uri("http://localhost/api/1.0/version");
UriTemplateMatch match = table.MatchSingle(uri);
Console.WriteLine("{0}", match.Template.ToString());
}
The dot is not an illegal character in URLs, RequestPathInvalidCharacters does not exclude it, there are no rewrite rules in place that could interfere. Couldn't find anything in the documentation on it either.
While there is an obvious workaround, not use the dot in the template, I'm curious as to why it fails with 'HTTP 404/The resource cannot be found'.

I ran into the same issue before. I realized it was a limitation in IIS, and nothing to do with WCF. When IIS initially intercepts the request assumes the value following the . represents an extension, so it tries to find a managed handler for that extension. Since it does not find any, it just throws a 404.
Regards
Pablo.

Related

Using a local image with EmbedBuilder

According to the Discord.NET documentation page for the EmbedBuilder class, the syntax (converted to VB) to add a local image to an EmbedBuilder object should look something like this:
Dim fileName = "image.png"
Dim embed = New EmbedBuilder() With {
.ImageUrl = $"attachment://{fileName}"
}.Build()
I'm trying to use something like this to add a dynamically created image to the EmbedBuilder, but I can't seem to get it to work properly. Here's basically what I've got:
Dim TweetBuilder As New Discord.EmbedBuilder
Dim DynamicImagePath As String = CreateDynamicImage()
Dim AttachURI As String = $"attachment:///" & DynamicImagePath.Replace("\", "/").Replace(" ", "%20")
With Builder
.Description = "SAMPLE DESCRIPTION"
.ImageUrl = AttachURI
End With
MyClient.GetGuild(ServerID).GetTextChannel(PostChannelID).SendMessageAsync("THIS IS A TEST", False, Builder.Build)
My CreateDynamicImage method returns the full path to the locally created image (e.g., C:\Folder\Another Folder\image.png). I've done a fair amount of "fighting"/testing with this to get past the Url must be a well-formed URI exception I was initially getting because of the [SPACE] in the path.
MyClient is a Discord.WebSocket.SocketClient object set elsewhere.
The SendMessageAsync method does send the Embed to Discord on the correct channel, but without the embedded image.
If I instead send the image using the SendFileAsync method (like so):
MyClient.GetGuild(ServerID).GetTextChannel(PostChannelID).SendFileAsync(DynamicImagePath, "THIS IS A TEST", False, Builder.Build)
the image is sent, but as a part of the message, rather than included as a part of the Embed (this is expected behavior - I only bring it up b/c it was a part of my testing to ensure that there wasn't a problem with actually sending the image to Discord).
I've tried using the file:/// scheme instead of the attachment:/// scheme, but that results in the entire post never making it to Discord at all.
Additionally, I've tried setting the ImageUrl property to a Web resource (e.g., https://www.somesite.com/someimage.png) and the Embed looks exactly as expected with the image and everything when it successfully posts to Discord.
So, I'm just wondering at this point if I'm just missing something, or if I'm just doing it completely wrong?
I cross-posted this to issue #1609 in the Discord.Net GitHub project to get a better idea of what options are available for this and received a good explanation of the issue:
The Embed (and EmbedImage) objects don't do anything with files. They simply pass the URI as configured straight into Discord. Discord then expects a URI in the form attachment://filename.ext if you want to refer to an attached image.
What you need to do is use SendFileAsync with the embed. You have two options here:
Use SendFileAsync with the Stream stream, string filename overload. I think this makes it clear what you need to do: you provide a file stream (via File.OpenRead or similar) and a filename. The provided filename does not have to match any file on disk. > So, for example:
var embed = new EmbedBuilder()
.WithImageUrl("attachment://myimage.png")
.Build();
await channel.SendFileAsync(stream, "myimage.png", embed: embed);
Alternatively, you can use SendFileAsync with the string filePath overload. Internally, this gets a stream of the file at the path, and sets filename (as sent to Discord) to the last part of the path. So it's equivalent to:
using var stream = File.OpenRead(filePath);
var filename = Path.GetFileName(filePath);
await channel.SendFileAsync(stream, filename);
From here, you can see that if you want to use the string filePath overload, you need to set embed image URI to something like $"attachment://{Path.GetFileName(filePath)}", because the attachment filename must match the one sent to Discord.
I almost had it with my code above, but I misunderstood the intention and usage of the method and property. I guess I thought the .ImageUrl property somehow "automatically" initiated a Stream in the background. Additionally, I missed one very important piece:
As it's an async method, you must await (or whatever the VB.NET equivalent is) on SendFileAsync.
So, after making my calling method into an async method, my code now looks like this:
Private Async Sub TestMessageToDiscord()
Dim Builder As New Discord.EmbedBuilder
Dim AttachmentPath As String = CreateDynamicImage() '<-- Returns the full, local path to the created file
With Builder
.Description = "SAMPLE DESCRIPTION"
.ImageUrl = $"attachment://{IO.Path.GetFileName(AttachmentPath)}"
End With
Using AttachmentStream As IO.Stream = IO.File.OpenRead(AttachmentPath)
Await MyClient.GetGuild(ServerID).GetTextChannel(PostChannelID).SendFileAsync(AttachmentStream, IO.Path.GetFileName(AttachmentPath), "THIS IS A TEST", False, Builder.Build)
End Using
End Sub
Now, everything works exactly as expected and I didn't have to resort to uploading the image to a hosting site and using the new URL (I actually had that working before I got the response on GitHub. I'm sure that code won't go to waste).
EDIT
Okay, so I still ended up going back to my separately hosted image option for one reason: I have a separate event method that modifies the original Embed object during which I want to remove the image and replace the text. However, when that event fired, while the text was replaced, the image was "moved" to the body of the Discord message. While I may have been able to figure out how to get rid of the image entirely, I decided to "drop back and punt" since I had already worked out the hosted image solution.
I've tried everyting I could, but I got stuck at the same point at where you are now.
My guesses are that Discord doesn't like the embedded images from https://cdn.discordapp.com/attachments, and only accepts the new files from https://media.discordapp.net. I might be wrong though, this is the way it worked for me.
I believe it's only a visual glitch, as I found if you send a link for an image from cdn.discordapp.com/attchments in your regular Discord client, it bugs out and shows an empty embed for some reason.
That would make sense since the default link used in an embedded image actually starts with https://cdn.discordapp.com/attachments/...
You could solve this issue by using https://media.discordapp.net, but it seems like Discord.net is configured to use the old domain.

ServiceRoute does not work when routePrefix is a path

When I try to access my WCF service at the following address it works fine:
http://localhost/webservices/main.svc
Great. But I want to be able to call this service in following way:
http://localhost/api/main
So I am attempting to put in the proper ServiceRoute within the RouteConfig definitions in my MVC. I am able to make the routing work when the routePrefix variable is singular. But I cannot get it to work when routePrefix it is a path such as, as in my case, I want to map a route to ~/api/main.
I've scoured around The Google and this particular question is not common. I am pretty much seeking to accomplish the similar to what is stated in the accepted answer of the following previously posted question on this topic:
Expose WCF services that belong to an Area in MVC app at a routed path
I also attempted to implement a route constraint as suggested here: http://geekswithblogs.net/michelotti/archive/2010/09/22/wcf-rest-services-inside-mvc-projects.aspx
But still get the following error:
No HTTP resource was found that matches the request URI 'http://localhost/api/main'.
No type was found that matches the controller named 'main'.
Here is what I've attempted so far:
Imports System.Web.Mvc
Imports System.Web.Routing
Imports System.ServiceModel.Activation
Imports MyServiceLibrary
Public Class RouteConfig
Public Shared Sub RegisterRoutes(ByVal routes As RouteCollection)
[..other routing stuff...]
routes.Add(New ServiceRoute("api/main", New ServiceHostFactory(), _
GetType(MyServiceLibrary.main)))
routes.MapRoute("Default", "{controller}/{action}/{id}", New With { _
Key .controller = "Default1", _
Key .action = "Index", _
Key .id = UrlParameter.Optional}, _
New With {Key .controller = "^(?!main).*"})
[..other routing stuff...]
End Sub
End Class
Can't seem to figure out the fix on this.
EDIT 2:
When I first posted this question I had a problem with what turned out to be malformed VB syntax.
The original INCORRECT syntax:
routes.Add(new ServiceRoute("api/main", new ServiceHostFactory(), _
typeof(MyServiceLibrary.main)))
The CORRECT vb syntax should be:
routes.Add(New ServiceRoute("api/main", New ServiceHostFactory(), _
GetType(MyServiceLibrary.main)))
Notice that in VB you should use GetType instead of typeof. Fixing this was a good step forward, but did not solve the underlying problem.
EDIT 3:
Well, turns out if I modify the ServiceRoute as follows, then IT WORKS:
routes.Add(New ServiceRoute("main", New ServiceHostFactory(), _
GetType(MyServiceLibrary.main)))
So, the question is how to create the route i desire "api/main"...
EDIT 4:
I thought I might have found the solution here: Can a WCF ServiceRoute Route Prefix contain a path value?
The solution there notably implements WebServiceHostFactory instead of ServiceHostFactory. I tried it, but it didn't work for me.
You should pass in the wcf service type as Type. That is the service defined in your web.config file.
Take a look at this page:
http://blogs.msdn.com/b/endpoint/archive/2010/01/25/using-routes-to-compose-wcf-webhttp-services.aspx

How can I POST (as XML) an object to my ApiController using RestSharp?

I have an ASP.NET MVC4 website implementing a REST API, which I'm consuming from a client application. My ApiController methods take and return complex objects, as XML.
I recently discovered RestSharp, and have begun moving my client project over to that. However, I'm having real problems with it. It seems to almost work - it's so close that I can almost taste success - but I just can't get it to work 100%.
The objects I'm passing across the wire look something like this:
// The object I'm passing across the wire
public class Example
{
bool IsActive { get; set; }
string Name { get; set; }
}
My ApiController method looks like this:
// My ApiController method
public HttpResponseMessage PostExample(Example example)
{
if (ModelState.IsValid)
{
db.Examples.Add(example);
db.SaveChanges();
HttpResponseMessage response = Request.CreateResponse(HttpStatusCode.Created, example);
return response;
}
else
{
return Request.CreateResponse(HttpStatusCode.BadRequest);
}
}
The problem occurs when I try to POST an object to my website, like this:
var example = new Example () { IsActive = true, Name = "foo" };
var request = new RestSharp.RestRequest("/api/example", RestSharp.Method.POST);
request.AddBody(example, XmlNamespace);
var client = new RestClient();
client.BaseUrl = "foo.com";
var response = client.Execute<Example>(request);
The code above does hit the PostExample method in my ApiController, and it has an Example object as the parameter. However the values of the properties of the Example object are not the same as I passed to the Execute method! In one case, the IsActive member was false instead of true, although I also saw a case where the Name member was null where it should have had a value.
I did some investigation using Fiddler, and it seems that the correct values are being created in the XML that RestSharp generates. However, the XML is not quite in the same format that the web server emits when doing a GET. The differences are subtle, but seem to make the difference between it working and not working. The framework at the web server end seems to be sensitive to these formatting differences, and is mis-interpreting the XML as a result.
Here's the XML I get from RestSharp:
<Example xmlns="http://schemas.datacontract.org/2004/07/ExampleNamespace">
<Name>foo</Name>
<IsActive>true</IsActive>
</Example>
This is what I get when doing a GET on the webserver (or when serializing using the DataContractSerializer, which is what I was previously doing):
<Example xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://schemas.datacontract.org/2004/07/ExampleNamespace">
<IsActive>true</IsActive>
<Name>foo</Name>
</TagDto>
The RestSharp version has the following differences from the DataContractSerializer's version:
Fields are in a different order
RestSharp doesn't include the extra namespace XMLSchema-instance namespace
DataContractSerializer doesn't include any spaces or line-breaks (I added those above for readability)
I'm surprised that any of those make much of a difference, but clearly they do. Note also that until I added an explicit namespace in the AddBody call, this was missing in the generated XML (obviously), and the Example object passed into my ApiController was null.
Anyway, I noticed that RestSharp allows you to override the serializer, and provides a way to use the .NET XML serializer. I tried using that (to no avail).
This is what I added before the call to AddBody:
request.XmlSerializer = new RestSharp.Serializers.DotNetXmlSerializer(XmlNamespace);
..and this is what I get out:
<?xml version="1.0" encoding="utf-8"?>
<Example>
<Name>foo</Name>
<IsActive>true</IsActive>
</Example>
This is clearly no good, not least because it starts with an XML declaration, which I imagine would cause problems. There's no way to turn that off, because the RestSharp derived class provides no way to do so. Also, there's no namespace - and I can't get one to appear in the output no matter how I try to set the namespace in RestSharp (in the constructor for the DotNetXmlSerializer, by setting the Namespace member, or by passing in a namespace to AddBody). To my eyes, this class is nothing more than a trap.
It looks like my only option is to create my own serializer class and use the DataContractSerializer internally. Is that right, or am I missing something?
(BTW, I can set the RequestFormat of the request to JSON and it just works - but I'd still like to know how to get this working with XML).
I've had some issues with the AddBody calls not properly serializing JSON values, so there might be some similarity to your problem. Instead of AddBody, you could try:
request.AddParameter("text/xml", xmlAsString, ParameterType.RequestBody);
If that works, you could look to see about changing the second parameter to be the xml object and see if the serializer does what you want.
The other option could be the XmlMediaTypeFormatter.ReadFromStreamAsync isn't properly picking up a proper serializer; you could try overriding that function.
The issue above is because WebAPI is using the DataContractSerializer (as opposed to the XmlSerializer which is what you're after). To switch this around modify Global.asax as follows.
var xml = GlobalConfiguration.Configuration.Formatters.XmlFormatter;
xml.UseXmlSerializer = true;
However, I suggest you use the RESTSharp formatters for WebAPI (instead of using the .Net formatters). This is particularly useful if you're DTO's have circular references (the .net fx serializers don't handle this too gracefully).
In Global.asax, modify the formatters by putting in
GlobalConfiguration.Configuration.Formatters.XmlFormatter = //RestSharp XML serializer here
A quick overview of serialization in WebAPI is here and worth a browse

Apache Error is incompatible with throws class

I've got a quick question. In my grails project I am making some web service calls. One of the calls (for a search function) tends to timeout if not enough characters are given to search for. I can't increase the number of required characters so I instead am trying to catch the exception and display an error page asking the user to add more detailed parameters.
The method looks like this:
import org.apache.http.client.HttpResponseException
class RestSearchService implements SearchService {
List<Person> getPersonSearch( String fName, String lName) throws HttpResponseException {
...
// Make the call
...
}
}
I then catch the thrown exception in the controller to redirect to the error page. I've tested it and this code appears to work fine. The problem is that the method above is underlined (I'm using SpringSource Tool Suite for an IDE) and says
Exception HttpResponseException is not compatible with
throws clause in SearchService.getPersonSearch(String, String)
Does anyone know what might be causing this? Also, might it mean that there is an actual problem or circumstance where this will cause the app to break? Like I said, from what I can tell the throw/redirect is working like a champ, but that error makes me nervous about moving the app to production.
Thanks in advance,
-Mike
I would say that your interface SearchService is not right! what is the signature of the method 'getPersonSearch' in the interface?
its like this:
List<Person> getPersonSearch( String fName, String lName);
or like this:
List<Person> getPersonSearch( String fName, String lName) throws HttpResponseException;
the second one is correct, if you have the first one, thats should be the problem!

Getting Path (context root) to the Application in Restlet

I am needing to get the application root within a Restlet resource class (it extends ServerResource). My end goal is trying to return a full explicit path to another Resource.
I am currently using getRequest().getResourceRef().getPath() and this almost gets me what I need. This does not return the full URL (like http://example.com/app), it returns to me /resourceName. So two problems I'm having with that, one is it is missing the schema (the http or https part) and server name, the other is it does not return where the application has been mounted to.
So given a person resource at 'http://dev.example.com/app_name/person', I would like to find a way to get back 'http://dev.example.com/app_name'.
I am using Restlet 2.0 RC3 and deploying it to GAE.
It looks like getRequest().getRootRef().toString() gives me what I want. I tried using a combination of method calls of getRequest().getRootRef() (like getPath or getRelativePart) but either they gave me something I didn't want or null.
Just get the base url from service context, then share it with the resources and add resource path if needed.
MyServlet.init():
String contextPath = getServletContext().getContextPath();
getApplication().getContext().getAttributes().put("contextPath", contextPath);
MyResource:
String contextPath = getContext().getAttributes().get("contextPath");
request.getRootRef() or request.getHostRef()?
The servlet's context is accessible from the restlet's application:
org.restlet.Application app = org.restlet.Application.getCurrent();
javax.servlet.ServletContext ctx = ((javax.servlet.ServletContext) app.getContext().getAttributes().get("org.restlet.ext.servlet.ServletContext"));
String path = ctx.getResource("").toString();