When using WCF Data Services Client to communicate with my OData API, I occasionally need to use the
AddRelatedObject method of System.Data.Services.Client.DataServiceContext
This generates a POST to the endpoint that looks like:
http://base_url/odata/Entity(key)/NavigationProperty
The content of the http request is the serialized NavigationProperty entity.
Since a post to this URL is unmapped in a default odata controller, I wrote a new EntitySetRoutingConvention class:
Public Class AddRelatedObjectRoutingConvention
Inherits EntitySetRoutingConvention
Public Overrides Function SelectAction(odataPath As Http.OData.Routing.ODataPath, controllerContext As Http.Controllers.HttpControllerContext, actionMap As ILookup(Of String, Http.Controllers.HttpActionDescriptor)) As String
If controllerContext.Request.Method = Net.Http.HttpMethod.Post Then
If odataPath.PathTemplate = "~/entityset/key/navigation" Then
If actionMap.Contains("AddRelation") Then
Return "AddRelation"
End If
End If
End If
Return Nothing
End Function
End Class
I added this to the default routing conventions list and passed it to the MapODATARoute routine.
In my base controller I implemented AddRelation, and it is called perfectly.
From this I am able to get the odatapath, and parse it to determine the types and keys that are needed.
The problem I am having, is that once I know that my parent entity is a Tenant with a key of 1, and that the NavigationProperty of Users in the Tenant entity is a User entity, I can not figure out how to manually call an odatamediatypeformatter to deserialize the http content into the User entity so that I can then add it to the Tenants Users collection.
I have reviewed the OData source in an effort to find out how to the Web-API pipeline calls and deserializes the entity but have been unable to find the point at which the OData library takes the http content and turns it into an entity.
If anyone has an ideas to point me in the right direction, I will continue researching and update if I figure out more.
UPDATE 06/28/2013
Thanks to RaghuRam, I've been able to get closer. The problem I'm seeing is that the request.getconfiguration().formatters, or odatamediatypeformatters.create both seem to create type specific deserializers.
When I call ReadAsAsync I receive the error:
No MediaTypeFormatter is available to read an object of type 'User' from content with media type 'application/atom+xml'.
As the post shows above, the context of the controller is a Tenant, so I believe the formatters are typed to a Tenant and so can't deserialize the User.
I tried manually creating a formatter, _childDefinition is the EDM Type Reference from the navigation property of the odatapath. In this case a User.
Dim dser As New Formatter.Deserialization.ODataEntityDeserializer(_childDefinition, New Formatter.Deserialization.DefaultODataDeserializerProvider)
Dim ser As New Formatter.Serialization.ODataEntityTypeSerializer(_childDefinition, New Formatter.Serialization.DefaultODataSerializerProvider)
Dim dprovider As New Formatter.Deserialization.DefaultODataDeserializerProvider
dprovider.SetEdmTypeDeserializer(_childDefinition, dser)
Dim sprovider As New Formatter.Serialization.DefaultODataSerializerProvider
sprovider.SetEdmTypeSerializer(_childDefinition, ser)
Dim fmt As New Formatter.ODataMediaTypeFormatter(dprovider, sprovider, New List(Of Microsoft.Data.OData.ODataPayloadKind) From {Microsoft.Data.OData.ODataPayloadKind.Entry})
fmt.SupportedEncodings.Add(System.Text.Encoding.UTF8)
fmt.SupportedEncodings.Add(System.Text.Encoding.Unicode)
fmt.SupportedMediaTypes.Add(Headers.MediaTypeHeaderValue.Parse("application/atom+xml;type=entry"))
fmt.SupportedMediaTypes.Add(New Headers.MediaTypeHeaderValue("application/atom+xml"))
I have then tried:
request.content.ReadAsAsync(of User)(new List(of odatamediatypeformatter) from {fmt})
request.content.ReadAsAsync(of User)(request.getConfiguration().formatters)
request.content.ReadAsAsync(of User)(odatamediatypeformatters.create)
All giving the same error, it seems like I'm missing something obvious.
Thanks!
Steve
Just add a parameter of type User to your AddRelation action and you should be good. Web API would automatically invoke the OData formatter to read the User from the request body and bind it to your action parameter.
You can use this helper method to read OData request body,
private static Task<T> ReadODataContentAsAsync<T>(HttpRequestMessage request)
{
var formatters =
ODataMediaTypeFormatters.Create()
.Select(formatter => formatter.GetPerRequestFormatterInstance(typeof(T), request, request.Content.Headers.ContentType));
return request.Content.ReadAsAsync<T>(formatters);
}
like this,
Customer addedCustomer = ReadODataContentAsAsync<Customer>(Request).Result;
Related
In ASP.Net Core you have multiple ways to generate an URL for controller action, the newest being tag helpers.
Using tag-helpers for GET-requests asp-route is used to specify route parameters. It is from what I understand not supported to use complex objects in route request. And sometimes a page could have many different links pointing to itself, possible with minor addition to the URL for each link.
To me it seems wrong that any modification to controller action signature requires changing all tag-helpers using that action. I.e. if one adds string query to controller, one must add query to model and add asp-route-query="#Model.Query" 20 different places spread across cshtml-files. Using this approach is setting the code up for future bugs.
Is there a more elegant way of handling this? For example some way of having a Request object? (I.e. request object from controller can be put into Model and fed back into action URL.)
In my other answer I found a way to provide request object through Model.
From the SO article #tseng provided I found a smaller solution. This one does not use a request object in Model, but retains all route parameters unless explicitly overridden. It won't allow you to specify route through an request object, which is most often not what you want anyway. But it solved problem in OP.
<a asp-controller="Test" asp-action="HelloWorld" asp-all-route-data="#Context.GetQueryParameters()" asp-route-somestring="optional override">Link</a>
This requires an extension method to convert query parameters into a dictionary.
public static Dictionary GetQueryParameters(this HttpContext context)
{
return context.Request.Query.ToDictionary(d => d.Key, d => d.Value.ToString());
}
There's a rationale here that I don't think you're getting. GET requests are intentionally simplistic. They are supposed to describe a specific resource. They do no have bodies, because you're not supposed to be passing complex data objects in the first place. That's not how the HTTP protocol is designed.
Additionally, query string params should generally be optional. If some bit of data is required in order to identify the resource, it should be part of the main URI (i.e. the path). As such, neglecting to add something like a query param, should simply result in the full data set being returned instead of some subset defined by the query. Or in the case of something like a search page, it generally will result in a form being presented to the user to collect the query. In other words, you action should account for that param being missing and handle that situation accordingly.
Long and short, no, there is no way "elegant" way to handle this, I suppose, but the reason for that is that there doesn't need to be. If you're designing your routes and actions correctly, it's generally not an issue.
To solve this I'd like to have a request object used as route parameters for anchor TagHelper. This means that all route links are defined in only one location, not throughout solution. Changes made to request object model automatically propagates to URL for <a asp-action>-tags.
The benefit of this is reducing number of places in the code we need to change when changing method signature for a controller action. We localize change to model and action only.
I thought writing a tag-helper for a custom asp-object-route could help. I looked into chaining Taghelpers so mine could run before AnchorTagHelper, but that does not work. Creating instance and nesting them requires me to hardcode all properties of ASP.Net Cores AnchorTagHelper, which may require maintenance in the future. Also considered using a custom method with UrlHelper to build URL, but then TagHelper would not work.
The solution I landed on is to use asp-all-route-data as suggested by #kirk-larkin along with an extension method for serializing to Dictionary. Any asp-all-route-* will override values in asp-all-route-data.
<a asp-controller="Test" asp-action="HelloWorld" asp-all-route-data="#Model.RouteParameters.ToDictionary()" asp-route-somestring="optional override">Link</a>
ASP.Net Core can deserialize complex objects (including lists and child objects).
public IActionResult HelloWorld(HelloWorldRequest request) { }
In the request object (when used) would typically have only a few simple properties. But I thought it would be nice if it supported child objects as well. Serializing object into a Dictionary is usually done using reflection, which can be slow. I figured Newtonsoft.Json would be more optimized than writing simple reflection code myself, and found this implementation ready to go:
public static class ExtensionMethods
{
public static IDictionary ToDictionary(this object metaToken)
{
// From https://geeklearning.io/serialize-an-object-to-an-url-encoded-string-in-csharp/
if (metaToken == null)
{
return null;
}
JToken token = metaToken as JToken;
if (token == null)
{
return ToDictionary(JObject.FromObject(metaToken));
}
if (token.HasValues)
{
var contentData = new Dictionary();
foreach (var child in token.Children().ToList())
{
var childContent = child.ToDictionary();
if (childContent != null)
{
contentData = contentData.Concat(childContent)
.ToDictionary(k => k.Key, v => v.Value);
}
}
return contentData;
}
var jValue = token as JValue;
if (jValue?.Value == null)
{
return null;
}
var value = jValue?.Type == JTokenType.Date ?
jValue?.ToString("o", CultureInfo.InvariantCulture) :
jValue?.ToString(CultureInfo.InvariantCulture);
return new Dictionary { { token.Path, value } };
}
}
I got a CXF OSGi Web service (based on the example demo in servicemix: https://github.com/apache/servicemix/tree/master/examples/cxf/cxf-jaxws-blueprint)
The Web service works fine and i call all the available implemented methods of the service.
My question is how can i retrieve the request inside a WS method and parse in a string XML format.
I have found that this is possible inside interceptors for logging, but i want also to the WS-Request inside my methods.
For storing the request in the database I suggest to extend the new CXF message logging.
You can implement a custom LogEventSender that writes into the database.
I had similar requirement where I need to save data into DB once method is invoked. I had used ThreadLocal with LoggingInInterceptor and LoggingOutInterceptor. For example in LoggingInInterceptor I used to set the message into ThreadContext and in webservice method get the message using LoggingContext.getMessage() and in LoggingOutInterceptor I used to removed the message(NOTE: Need to be careful here you need to explictly remove the message from thread context else you will end up with memory leak, and also incase of client side code interceptors get reversed.
public class LoggingContext {
private static ThreadLocal<String> message;
public static Optional<String> getMessage() {
return Optional.ofNullable(message.get());
}
public static void setMessage(final String message) {
LoggingContext.message = new ThreadLocal<>();
LoggingContext.message.set(message);
}
}
Not an answer to this question but i achieved to do my task by using JAXB in the end and do some manipulations there.
Maybe I'm thinking about this wrong, but I'm trying to create a custom attribute for our CMS to handle auth checks.
https://gist.github.com/sitefinitysteve/62ab761256a64a84d8a6#file-sitefinityjwt-cs-L39
So if this service is called from within the CMS from a logged in user, user data is all there for the service method already.
But in the context of being called from an app, the user is technically Anonymous, however I can decode the token and get the user just fine... but not sure how to like pass that over to the service.
Am I just maybe looking at this wrong, and the proper thing to do is to call a CMS API method to just log that person in (seems slow if I already have the persons user object from line 33, and the service context expires instantly.
Use Request.Items Dictionary
You would use the IRequest.Items dictionary for any data you want to pass throughout ServiceStack's Request Pipeline:
//RequestFilter:
req.Items["info"] = new MyRequestInfo { ... };
In Service:
var info = (MyRequestInfo)base.Request.Items["info"];
Have DTO's share common interface
Another option for adding extra info to your Service is to have Request DTO's implement an interfaces, e.g:
public interface IHasInfo
{
MyRequestInfo Info { get; set; }
}
Which you could then populate in your Request Filter, e.g:
((MyRequestInfo)dto).Info = new MyRequestInfo { ... };
Access in Service like any other DTO property, e.g:
public object Any(Request request)
{
var info = request.Info;
}
I am using ServiceStack's SocialBootstrapApi and it contains a class CustomUserSession that I can use to override the OnRegistered method. I want to override it because I am attempting to obtain information about the registration so that I can publish an event that a new user has registered. This handler provides an instance of the RegistrationService that handled the registration but not anything about the registration request itself or the resulting UserAuth instance. For instance, I'd like to get the e-mail address used to register.
public override void OnRegistered(IServiceBase registrationService)
{
base.OnRegistered(registrationService);
// Ideally, I could do get the registered user's primary e-mail address from the UserAuth instance.
var primaryEmail = ((RegistrationService) registrationService)
.UserAuthRepo
.GetUserAuth(this, null) //<--- 'this' is a mostly empty session instance
.PrimaryEmail;
}
This of course doesn't work because the session instance I'm using for the GetUserAuth call doesn't contain any of the necessary authentication information to be useful for looking up the user's authentication information. So GetUserAuth returns null as you would expect. So how should I go about obtaining this information? Would it be incorrect design for the OnRegistered handler to be passed the UserAuth instance created by the RegistrationService?
public interface IAuthSession
{
...
void OnRegistered(IServiceBase registrationService, UserAuth userAuth); // <-- new signature
...
}
That would be convenient! :)
Or perhaps there's another way to go about this?
Thanks in advance.
So how should I go about obtaining this information?
You should be able to access all the data of the Registration request via the registrationService. You just have to do a little digging and casting...
public override void OnRegistered(IServiceBase registrationService)
{
base.OnRegistered(registrationService);
var requestContext = (HttpRequestContext)registrationService.RequestContext;
var dto = ((Registration)requestContext.Dto);
var primaryEmail = dto.Email;
}
Would it be incorrect design for the OnRegistered handler to be passed the UserAuth instance created by the RegistrationService?
I'll leave design decisions to the professionals. The above code should work. The casting seems a bit ugly but all the necessary data is there.
I do not like hack into SS, so I chose to select user auth info from UserAuth collection by dto.UserName
I Need by service contract to return the xml/json result depending on the request type.I also need a kind of helper function which will convert my result set (i am using linq to sql) so that i do not need to create the xml format for the result set by iterating through the table row many times.What is the suitable way to do that.
I need a kind of short cut method which will convert the table data to xml result.Had i been using asp.net mvc i would have been able to generate the xml data by overriding the the ExecuteResult method in the ActionResult and giving Conetnt-Type = "text/xml" as OP.But since i am using
Wcf i don't have the controller context(as controller context is the parameter that needs to be passed to Execute Result).
My present code for converting the table data to the xml format is below.
public XDocument UsersLists(string authToken)
{
bool IsAuthenticated = Authenticate(authToken);
XDocument xDoc = new XDocument();
XElement root = new XElement("Users");
if (IsAuthenticated)
{
List<User> lstUsers = _lService.UserRepository.GetUserCompanyFromAccountID(GetAccountId(authToken)).ToList();
if (lstUsers != null)
{
root.Add(new XElement("Message", "Success"));
foreach (var u in lstUsers)
{
XElement chid = new XElement("User");
root.Add(new XElement("UserId", u.UserId));
root.Add(new XElement("FirstName", u.FirstName));
root.Add(new XElement("LastName", u.LastName));
root.Add(new XElement("Email", u.Email));
root.Add(new XElement("CompanyName", u.Company.CompanyName));
root.Add(chid);
}
xDoc.Add(root);
return xDoc;
}
else
{
return ReturnFailure(xDoc, root);
}
}
else
{
return ReturnFailure(xDoc, root);
}
}
I need to eliminate this way of generating xml for each table records.
An early response is priceless.
Thanks
Technology : Windows Communication Foundation.
Implementation of single operation returning both XML or JSON differs between WCF 3.5 or WCF 4.0. For implementing this feature in WCF 3.5 check this thread. Generally you will have to create custom behavior and set the content type based on Accept header from the request. WCF 4.0 has native support for this feature. WebHttpBehavior has property AutomaticFormatSelectionEnabled. If you set this property to true it should just work out of the box.
To your second question. You don't need any custom formatting like in ASP.NET MVC. Formatting in WCF is handled by serialization. Just return collection from your operation and you will see what happens. Linq-To-Sql generated entities should be serializable by default. Just don't forget to execute query before returning from method. If you need special format of date which is not the same as Linq-To-Sql entities create custom data type which have public parameterless constructor and all required properties with getter and setter. If you want to make it clear makr that class with DataContract attribute and all properties with DataMember attribute. Return collection of that custom class instances from your operation.