I am using WCF and .NET 4.5, working with a WCF SOAP web service that's been in production for some time. Need to rename a property, but there is a small chance that some of production customers may have the old property name in their requests.
For example, if a property was called MyPoorlyNamedProperty and I renamed it to MyProperty, I wish both MyPoorlyNamedProperty and MyProperty in SOAP would de-serialize to that same property.
Is there a way to decorate a property of a type in WCF to specify an "alternative" accepted name for the renamed property?
I don't know any alternative name decoration or anything similar. If you wish to create a breaking-change, you need to do one of both:
Change the property name and notify your clients that the contract was changed and they need to prepare accordingly
Modify your API to accept both properties. In case it recieves a request with value for the old property, set this value to the new property.
Solution 2 is ugly and not the best practice. I don't recommend doing it.
You can add the second property to your model. And work with get; set; and the DataMember attribute.
[DataContract]
public class Person
{
[DataMember]
private string _surname;
public string Surname { get { return this._surname; } set { this._surname = value; } }
public string Lastname { get { return this._surname; } set { this._surname = value; } }
}
Related
I am writing a proxy to wrap a WCF service with ASP.net Core and this is my first time using ASP.Net core.
I am using an auto-generated WCF service contract, and the issue is my WCF service changes frequently, so I must update/refresh the WCF service, and whenever I update my contract, I lose my minor tweaks.
I'm only trying to:
Hide some properties - via changing public string Property to internal string Property. I've tried [IgnoreDataMember] and [JsonIgnore] but those don't seem to work
Make some properties required - via RequiredAttribute
Default some property values - via DefaultValueAttribute
I've tried two approaches so far but they're not working fully.
This represents the automatically generated WCF Contract where I want to require & default MyProperty1 and hide MyProperty2:
// This is the automatically generated WCF Contract
public partial class MyClass
{
private string myPropertyField1;
private string myPropertyField2;
public string MyProperty1
{
get { return this.myPropertyField1; }
set { this.myPropertyField1 = value; }
}
public string MyProperty2
{
get { return this.myPropertyField2; }
set { this.myPropertyField2 = value; }
}
}
Method 1:
ModelMetadataType to override the contract metdata. This partially works, but not for all attributes for some reason? It feels like a bug.
[ModelMetadataType(typeof(MyClassMetadata))]
public partial class MyClass { }
public partial class MyClassMetadata
{
[Required] // This does not work
[DefaultValue("SomeValue")] // This DOES work?
public string MyProperty1 { get; set; } // I want this required & defaulted
[IgnoreDataMember] // This does not work to hide
[JsonIgnore] // This does not work to hide
public string MyProperty2 { get; set; } // I want this hidden from Swagger view
}
Which works to default values, but it doesn't appear to make it required or hidden?
Method 2:
I tried creating derived class, and then using the derived class instead of MyClass for the controller api arguments, but then when I try to call it I receive an error that says something like Type MyClassDerived was not expected. Use XmlInclude to specify unexpected types...
public partial class MyClassDerived : MyClass
{
[Required] // This puts "*" next to it in Swagger
[DefaultValue("SomeValue")] // This defaults the value in Swagger
public new string MyProperty1
{
get { return base.MyProperty1; }
set { base.MyProperty1 = value; }
}
internal new string MyProperty2 // This works to hide from Swagger
{
get { return base.MyProperty2; }
set { base.MyProperty2 = value; }
}
}
How can I hide/default/require contract properties without directly modifying an auto-generated WCF contract service class?
I have a WCF service which returns ExtensionDataObject during runtime as attached snapshot:
Im struck with fetching value for these objects. Could anyone please help here:
Have tried with below code using reflection, which throws Parameter count missing exception
List<System.Runtime.Serialization.ExtensionDataObject> extData = temp.Select(x => x.ExtensionData).ToList();
var GetCountry = extData.GetType().GetProperties();
string Country = string.Empty;
foreach (var property in GetCountry)
{
string name = property.Name;
object value = property.GetValue(extData, null);
if (name == "Country")
Country = value.ToString();
}
The Extensiondataobject field is generated to control the data contract incompatibility between the server and the client, so it will return a field named extensiondataobject. In other words, your client data contract implements the IExtensionDataObject interface.
[DataContract(Namespace="abcd")]
public class Product: IExtensibleDataObject
{
[DataMember]
public int ID { get; set; }
[DataMember]
public string Name { get; set; }
public ExtensionDataObject ExtensionData { get ; set ; }
}
If we capture this request through Fiddle, you can even see all the data directly.
In a word, you only need to add the Country property to the Data class of X object. It will be deserialized automatically. This class should be your client-side data contract class, instead of the server-side data class.
Finally, it seems that the value of these fields is null. We should ensure that the server and client data contracts have the same namespace. It cannot be the default value(http://tempuri.org). As I defined above, this namespace attribute should be consistent with the server-side value.
Feel free to let me know if there is anything I can help with.
Is is possible to bind properties from a JSON file (appsettings.json) to a class that uses different property names?
{
"WebTarget": {
"WebURL": "http://www.stackoverflow.com"
}
}
public class MyServiceOptions
{
public string Url { get; set; }
}
I want to take the WebURL setting and map it to the Url property in the options class. I've tried [DataMember] and [JsonProperty] but they don't work.
I know it's not ideal and the property names should match what's in the JSON but this one is a special case.
Yes it is possible. It requires a little more manual configuration
services.Configure<MyServiceOptions>(myOptions => {
myOptions.Url = Configuration.GetSection("WebTarget").GetValue<string>("WebURL", string.Empty);
});
Reference Configure simple options with a delegate
I am trying to handle multiple languages in an ASP.NET Webforms (.NET 4.5, C#) application of mine.
Basically, some of my entities in my SQL Server 2012 database have properties like Name or Description which exist in three languages - German, French, Italian.
Those are stored as columns Name_De (German), Name_Fr (French), and Name_It (Italian).
When I create my .NET objects from the database, of course, I also get those three properties in my entity class. But for displaying on screen, in a grid for instance, it would be nice if I could somehow "magically" always show the "right" language. This should be based on the Thread.Current.CurrentUICulture.TwoLetterISOLanguageName (which returns de, fr or it, depending on the browser's language preferences).
So I was hoping to somehow be able to create e.g. a .NET attribute that would allow me to do something like this:
Base "Module" entity - generated from existing SQL Server database:
public partial class Module
{
public string ModuleCode { get; set; }
public string Name_De { get; set; }
public string Name_Fr { get; set; }
public string Name_It { get; set; }
... // other properties
}
Partial extension in a separate file
public partial class Module
{
[Multilingual]
public string Name { get; set; }
}
The base idea is: I can access the Module.Name property, and depending on the current setting of CurrentUICulture, either the value of Name_De, Name_Fr or Name_It would be fetched, when I access the getter of the Name property.
Can something like this be done in C# ? I have looked at a lot of custom attribute implementations, but nothing ever seemed to be doing something like this...
Assuming you are using two separate entities (one generated by your SQL entities and one "business entity" which only contains a Name property), are you open to using something like AutoMapper ?
If you are, then you could tweak your resolve function to map the entity depending on the current thread culture.
switch(Thread.CurrentThread.CurrentUICulture.TwoLetterISOLanguageName.ToUpperInvariant())
{
case "DE":
return dto.Name_De;
case "FR":
return dto.Name_Fr;
// ...
default :
return String.Empty;
}
which would work for your scenario.
If this is a solution that could work for you, I think this question is very close to what you're looking for : Automapper Mapping for Localization Resolver in a Multi-Language Website
If you do go down the custom attribute route, you will have to deal with Reflection stuff and string parsing I'm afraid. AFAIK, there is no built in way to do this with the localization functions provided by .NET. AutoMapper will hide that from you.
The problem with custom attributes in this case is that you are still trying to access the Name property. You are trying to "shadow" the default behaviour of the property by making it access other properties. If I understand correctly you want the Multilingual custom attribute to turn your property into :
public String Name
{
get
{ switch(Thread.CurrentThread.CurrentUICulture.TwoLetterISOLanguageName.ToUpperInvariant())
{
case "DE":
return dto.Name_De;
case "FR":
return dto.Name_Fr;
// ...
default :
return String.Empty;
}
}
}
If that's correct, then you won't be able to do that easily with attributes, simply because the attribute will never be aware of the existence of the Name_De property.
Other option that still isn't quite what you're looking for :
void Main()
{
Module mod = new Module();
mod.Name_De = "name";
mod.Name_Fr = "nom";
// This is the unfortunate nasty bit. I address the property using its name
// in a String which is just bad. I don't think there is a way
// you will be able to address the ".Name" property directly and have
// it return the localized value through your custom attribute though
String localizedValue = mod.GetLocalizedProperty("Name");
}
[AttributeUsage(AttributeTargets.Property)]
public sealed class MultilingualAttribute : Attribute
{
public MultilingualAttribute()
{
}
}
public static class ModuleExtensions
{
public static String GetLocalizedProperty(this Module module, String propName)
{
var type = typeof(Module);
var propInfo = type.GetProperty(propName);
// Make sure the prop really is "Multilingual"
if(Attribute.IsDefined(propInfo, typeof(MultilingualAttribute)))
{
String localizedPropName = propInfo.Name;
switch(Thread.CurrentThread.CurrentUICulture.TwoLetterISOLanguageName.ToUpperInvariant())
{
case "DE":
localizedPropName += "_De";
return type.GetProperty(localizedPropName).GetValue(module, null).ToString();
case "FR":
localizedPropName += "_Fr";
return type.GetProperty(localizedPropName).GetValue(module, null).ToString();
}
}
return String.Empty;
}
}
public class Module
{
public String Name_De {get; set;}
public String Name_Fr {get; set;}
[Multilingual]
public String Name {get; set;}
public Module()
{
}
}
I don't know of a more powerful way to use custom attributes for what you're looking for unfortunately. Quite frankly, I don't think this is a good solution, only posted because I was trying to see what I could do with custom attributes. There is no real point in using this code over a more "normal" property which would do the same thing in a clearer way (without attributes). As you say in your original question, your goal is to intercept the call to the Name property and this doesn't achieve it.
Apparently my education has failed me, because I didn't realize that methods in C# cannot be serialized. (Good to know.)
I am trying to create a WCF service that returns a simple class I created. The problem is that this simple class contains methods that I want to expose, and the caller of my service won't have any access to them (assuming they won't have a .dll containing the class declaration).
public class Simple
{
public string Message { get; set; }
private const string _Hidden = "Underpants";
public string Hidden
{
get { return _Hidden; }
}
public string GetHidden()
{
return _Hidden;
}
}
I set up a WCF service (let's call it MyService) to return an instance of my Simple class. To my frustration, I'm only getting a partial build of my class back.
public void CallService()
{
using (var client = new MyService.Serviceclient())
{
Simple result = client.GetSimple();
string message = result.Message; // this works.
string hidden = result.Hidden; // this doesn't.
string fail = result.GetHidden(); // Underpants remains elusive.
}
}
Is there any type of workaround where I'm able to set up a property or method on my class that will be accessible to whomever calls my service? How does one handle constants or other methods that are set up in a class that only exists in a service?
Typically you would create three different projects.
1. Service project
2. Client project
3. Data project
The Data project contains only the data classes - no application code. The methods and constants in these data classes should be independent of the Service/Client projects.
The Data project is included as a reference in both the Service and Client projects so that serialization and deserialization happen against the same binary - and you get to retain your constants/methods/etc.
The downside here is that all your clients will either have to be .NET apps, or you will have to provide different data libraries for each platform you wish to support.
As far as I know the only things that can be returned in a WCF service are primitives or a class with public properties that have a get method on them. From a high level WCF exists to allow you to specify a contract between the client and the server that it in theory transportation agnostic (ie you can swap out an HTTP endpoint for a netTcp endpoint and the service will function the same way from a contractual level).
The question to answer then is what data are you trying to pass back in this service call. If it's an object called simple with the data points of Message and Hidden then I would advise creating a data class called Simple that has those values as properties:
[DataContract]
public class Simple
{
[DataMember]
public string Hidden { get; set; }
[DataMember]
public string Message { get; set; }
}
When the client receives the response back Message and Hidden will be populated with whatever you have set their values to on the server side.
The DataMember attribute can only be used on properties and fields. This means that a WCF response can only serialize these types.
If you really want to only use the const in your WCF contract You could convert it to a field and place the DataMember attribute on it:
public class Simple
{
[DataMember]
public string Message { get; set; }
[DataMember]
public const string Hidden = "Underpants";
}
To be able to do this the field must be accessible (public).
Add the DataMember attribute to your property. To do so, you must have both a get and a set defined.
[DataMember]
public string Hidden
{
get { return _Hidden; }
set { }
}
technically you could do
public class thingToSerialize{
public Func<ArgType1,ArgType2...,ReturnType> myFunction{get;set;}
}
and then assign it a lambda that takes the arguments and returns the return type
before serializing