I've got this compiletime errors when I make some class implement an interface with properties that have been fromerly defined in some native sub class, like openfl.display.Sprite. It occurs when I'm targeting flash, not js.
Field get_someValue needed by SomeInterface is missing
Field set_someValue needed by SomeInterface is missing
Field someValue has different property access than in SomeInterface (var should be (get,set))
In contrast, there's no problem with interface definitions of 'native' methods or 'non-native' properties. Those work.
Do I have to avoid that (not so typical) use of interfaces with haxe and rewrite my code? Or is there any way to bypass this problem?
Thanks in advance.
Example:
class NativePropertyInterfaceImplTest
{
public function new()
{
var spr:FooSprite = new FooSprite();
spr.visible = !spr.visible;
}
}
class FooSprite extends Sprite implements IFoo
{
public function new()
{
super();
}
}
interface IFoo
{
public var visible (get, set):Bool; // Cannot use this ):
}
TL;DR
You need to use a slightly different signature on the Flash target:
interface IFoo
{
#if flash
public var visible:Bool;
#else
public var visible (get, set):Bool;
#end
}
Additional Information
Haxe get and set imply that get_property():T and set_property(value:T):T both exist. OpenFL uses this syntax for many properties, including displayObject.visible.
Core ActionScript VM classes (such as Sprite) don't use Haxe get/set, but are native properties. This is why they look different.
Overriding Core Properties
If you ever need to override core properties like this, here is an example of how you would do so for both Flash and other targets on OpenFL:
class CustomSprite extends Sprite {
private var _visible:Bool = true;
public function new () {
super ();
}
#if flash
#:getter(visible) private function get_visible ():Bool { return _visible; }
#:setter(visible) private function set_visible (value:Bool):Void { _visible = value; }
#else
private override function get_visible ():Bool { return _visible; }
private override function set_visible (value:Bool):Bool { return _visible = value; }
#end
}
Overriding Custom Properties
This is not needed for custom properties, which are the same on all platforms:
class BaseClass {
public var name (default, set):String;
public function new () {
}
private function set_name (value:String) {
return this.name = value;
}
}
class SuperClass {
public function new () {
super ();
}
private override function set_name (value:String):String {
return this.name = value + " Q. Public";
}
}
Need to provide the method signatures in an Interface. Currently its just a property declaration.
The error message is saying it all.
Field get_someValue needed by SomeInterface is missing
Field set_someValue needed by SomeInterface is missing
Hopefully that helps.
Related
I am writing unit tests for a public method which is, in turn, calling a private method of the class written in typescript (Node JS).
Sample Code
class A {
constructor() {
}
public method1() {
if(this.method2()) {
// Do something
} else {
// Do something else
}
}
private method2() {
return true;
}
}
Now to test method1() I need to stub method2() which is a private method.
here what I am trying :
sinon.stub(A.prototype, "method2");
Typescript is throwing the error :
Argument of type '"method2"' is not assignable to parameter of type '"method1"'
Any help would be appreciated.
Thank You
The problem is that the definition for sinon uses the following definition for the stub function :
interface SinonStubStatic { <T>(obj: T, method: keyof T): SinonStub; }
This means that the second parameter must be the name of a member (a public one) of the T type. This is probably a good restriction generally, but in this case it is a bit too restrictive.
You can get around it by casting to any:
sinon.stub(A.prototype, <any>"method2");
Sometimes when the complexity of code and tests is more significant I prefer to "externalize" private methods. You can do that, that either with a (partial) class or a (partial) interface.
it('private methods test', async () => {
// original class
class A{
public method1():string{
if(this.method2()) {
// Do something
return "true";
} else {
// Do something else
return "false";
}
}
// with private method
private method2():boolean{
return true;
}
}
// interface that makes the private method public
interface IAExternalized{
method2():boolean;
}
// class that makes the private method public
class APrivate implements IAExternalized{
// with public method
method2():boolean{
return true;
};
}
// test before mocking
let test:A = new A();
let result:string = test.method1();
result.should.be.equal("true");
// let's mock the private method, but with typechecking available
let stubMethod2:sinon.SinonStub = sinon.stub(<IAExternalized><unknown>(A.prototype), "method2").returns(false);
result = test.method1();
result.should.not.be.equal("true");
result.should.be.equal("false");
// access private method of an object through public-interface
let testPrivate:IAExternalized = <IAExternalized><unknown>test;
let result2:boolean = testPrivate.method2();
result2.should.not.be.equal(true);
result2.should.be.equal(false);
});
NOTE: If you control the code you are testing, you do not need to double code, prone to mistakes, but you can make your class implement the interface. To convert standard (without private) interface into "externalized" you can extend it with public methods.
export interface IAExternalized extends IAPrivate {
method2():boolean
};
I am using Unity as IOC and trying to inject an interface with a factory method which takes a interface as a parameter.
For some reason the configReader parameter in the factory method GetTitleParser(), is null and not getting the injected ConfigurationReader() instance.
When i place a debug point at the line in RegisterTypes method where the new InjectionFactory exists, ITitleParser is not showing as mapped to a proper mapped type.
can anyone help what am i doing wrong here?
Here is my code:
public class UnityContainerBuilder
{
public static IUnityContainer Build()
{
var container = new UnityContainer();
RegisterTypes(container);
return container;
}
public static void RegisterTypes(IUnityContainer container)
{
// NOTE: To load from web.config uncomment the line below. Make sure to add a Microsoft.Practices.Unity.Configuration to the using statements.
container.LoadConfiguration();
container.RegisterType<IConfigurationReader, ConfigurationReader>();
container.RegisterType<ITitleParser>(new InjectionFactory(c => ParserFactory.GetTitleParser()));
}
}
public class ParserFactory
{
public static ITitleParser GetTitleParser(IConfigurationReader configReader=null)
{
if(configReader==null) configReader = new ConfigurationReader();
/* rest of code here...*/
return parser;
}
}
It works when i use the following code. Is this the right way to do this?
container.RegisterType<IConfigurationReader, ConfigurationReader>();
container.RegisterType<ITitleParser>(new InjectionFactory(c =>
{
var configReader = c.Resolve<IConfigurationReader>();
var parser = ParserFactory.GetTitleParser(configReader);
return parser;
}));
When you use default parameters it's equal to:
container.RegisterType<ITitleParser>(
new InjectionFactory(c => ParserFactory.GetTitleParser(null)));
Because, compiler inserts all default values in method calls (null in your case).
So, your code is valid:
container.RegisterType<ITitleParser>(new InjectionFactory(c =>
{
var configReader = c.Resolve<IConfigurationReader>();
var parser = ParserFactory.GetTitleParser(configReader);
return parser;
}));
But i advice you to remove default value to make code more expressive.
Your code is valid but maybe you can avoid messing up with InjectionFactory parameters and ParserFactory.
public class UnityContainerBuilder
{
public static IUnityContainer Build()
{
var container = new UnityContainer();
RegisterTypes(container);
return container;
}
public static void RegisterTypes(IUnityContainer container)
{
// NOTE: To load from web.config uncomment the line below. Make sure to add a Microsoft.Practices.Unity.Configuration to the using statements.
container.LoadConfiguration();
container.RegisterType<IConfigurationReader, ConfigurationReader>();
container.RegisterInstance<IAppConfig>(container.Resolve<IConfigurationReader>().ReadConfiguration());
container.RegisterType<ITitleParser, TitleParser>();
}
}
public class AppConfig: IAppConfig
{
public AppConfig(){}
//value1 property
//value2 property
//etc
}
public class ConfigurationReader: IConfigurationReader
{
public ConfigurationReader(){}
public IAppConfig ReadConfiguration(){
var currentConfig = new AppConfig();
//read config from file, DB, etc and init currentCongif
return currentConfig;
}
}
public class TitleParser : ITitleParser
{
public TitleParser(IAppConfif)
{
//config already readed, just do the work
}
}
Consider the following existing classes which uses MEF to compose Consumer.
public interface IProducer
{
void Produce();
}
[Export(typeof(IProducer))]
public class Producer : IProducer
{
public Producer()
{
// perform some initialization
}
public void Produce()
{
// produce something
}
}
public class Consumer
{
[Import]
public IProducer Producer
{
get;
set;
}
[ImportingConstructor]
public Consumer(IProducer producer)
{
Producer = producer;
}
public void DoSomething()
{
// do something
Producer.Produce();
}
}
However, the creation of Producer has become complex enough that it can no longer be done within the constructor and the default behavior no longer suffices.
I'd like to introduce a factory and register it using a custom FactoryAttribute on the producer itself. This is what I have in mind:
[Export(typeof(IProducer))]
[Factory(typeof(ProducerFactory))]
public class Producer : IProducer
{
public Producer()
{
// perform some initialization
}
public void Produce()
{
// produce something
}
}
[Export]
public class ProducerFactory
{
public Producer Create()
{
// Perform complex initialization
return new Producer();
}
}
public class FactoryAttribute : Attribute
{
public Type ObjectType
{
get;
private set;
}
public FactoryAttribute(Type objectType)
{
ObjectType = objectType;
}
}
If I had to write the "new" code myself, it may very well look as follows. It would use the factory attribute, if it exists, to create a part, or default to the MEF to create it.
public object Create(Type partType, CompositionContainer container)
{
var attribute = (FactoryAttribute)partType.GetCustomAttributes(typeof (FactoryAttribute), true).FirstOrDefault();
if (attribute == null)
{
var result = container.GetExports(partType, null, null).First();
return result.Value;
}
else
{
var factoryExport = container.GetExports(attribute.ObjectType, null, null).First();
var factory = factoryExport.Value;
var method = factory.GetType().GetMethod("Create");
var result = method.Invoke(factory, new object[0]);
container.ComposeParts(result);
return result;
}
}
There are a number of articles how to implement a ExportProvider, including:
MEF + Object Factories using Export Provider
Dynamic Instantiation
However, the examples are not ideal when
The application has no dependencies or knowledge of Producer, only IProducer. It would not be able to register the factory when the CompositionContainer is created.
Producer is reused by several applications and a developer may mistakenly forget to register the factory when the CompositionContainer is created.
There are a large number of types that require custom factories and it may pose a maintenance nightmare to remember to register factories when the CompositionContainer is created.
I started to create a ExportProvider (assuming this would provide the means to implement construction using factory).
public class FactoryExportProvider : ExportProvider
{
protected override IEnumerable<Export> GetExportsCore(ImportDefinition definition,
AtomicComposition atomicComposition)
{
// What to do here?
}
}
However, I'm having trouble understanding how to tell MEF to use the factory objects defined in the FactoryAttribute, and use the default creation mechanism if no such attribute exists.
What is the correct manner to implement this? I'm using MEF 2 Preview 5 and .NET 4.
You can make use of a property export:
public class ProducerExporter
{
[Export]
public IProducer MyProducer
{
get
{
var producer = new Producer();
// complex initialization here
return producer;
}
}
}
Note that the term factory isn't really appropriate for your example, I would reserve that term for the case where the importer wants to create instances at will, possibly by providing one or more parameters. That could be done with a method export:
public class ProducerFactory
{
[Export(typeof(Func<Type1,Type2,IProducer>)]
public IProducer CreateProducer(Type1 arg1, Type2 arg2)
{
return new Producer(arg1, arg2);
}
}
On the import side, you would then import a Func<Type1,Type2,IProducer> that you can invoke at will to create new instances.
Given this class:
class Foo
{
readonly ILog log;
public Foo(ILog log)
{
this.log = log;
}
...
}
I'd like to configure Unity to inject ILog. That's easy:
container.RegisterInstance<ILog>(LogManager.GetLogger(typeof(XYZ)));
But I'd like to make Unity call LogManager.GetLogger with the type of the parent type being resolved.
This is close:
container.RegisterType<ILog>(new InjectionFactory((c, t, s) => LogManager.GetLogger(t)));
But t in this case is the type being resolved (ILog), not the type that the object is being resolved for (Foo).
I know I can do this:
container.RegisterType<Foo>(new InjectionFactory(c => new Foo(LogManager.GetLogger(typeof(Foo)));
But I don't want to have to add that crazy declaration every time I register an object.
I know this can be done in Autofac, and I know the Real Answer is not to use Unity in the first place, but can this be done? :)
Unity might not give you all the goodies some of the other containers offer but I have yet to find a feature you can't easily add.
var container = new UnityContainer();
container.AddNewExtension<TrackingExtension>();
container.RegisterType<ILog>(
new InjectionFactory((ctr, type, name) =>
{
var tracker = ctr.Resolve<ITracker>();
var parentType = tracker.CurrentBuildNode.Parent.BuildKey.Type;
return LogManager.GetLogger(parentType);
}));
var sut = container.Resolve<UsesLog>();
Assert.AreEqual(typeof(UsesLog), sut.Log.Type);
You can find the source code for the TrackingExtension here. Its located in the TecX.Unity project folder.
If you want a DI container to return you a logger based on the class’ type information, then put the type information into the public interface so the DI container can see it. It removes the need for any container specific override features and then it won’t matter if you are using Unity or AutoFac.
Someone that knows the log4net object model well might be able to give you a more efficient implementation, but try something like this:
using System;
using Microsoft.Practices.Unity;
using Microsoft.VisualStudio.TestTools.UnitTesting;
namespace UnityLoging
{
public interface ILog<T> : log4net.ILog
{ }
public class MyLogger<T> : log4net.Core.LogImpl, ILog<T>
{
public MyLogger() : base(log4net.LogManager.GetLogger(typeof(T).Name).Logger)
{ }
}
public class ClassToLog
{
private readonly log4net.ILog log;
public ClassToLog(ILog<ClassToLog> log)
{
this.log = log;
}
public void LogMe()
{
log.Debug("Got here");
}
}
[TestClass]
public class TestClass
{
[TestMethod]
public void GenericLogRegistrationTest()
{
log4net.Config.XmlConfigurator.Configure();
IUnityContainer container = new UnityContainer();
container.RegisterType(typeof(ILog<>), typeof(MyLogger<>));
ClassToLog c = container.Resolve<ClassToLog>();
c.LogMe();
log4net.LogManager.Shutdown();
}
}
}
This seems like a very clean approach: https://github.com/roblevine/UnityLoggingExtensions
I have a validation interface like so:
public interface IValidation<T> {
bool IsValid(T item, ref AggregateException fail);
}
I have a file importer that needs several validation interfaces
public FileImporter {
IEnumerable<IValidation<Patient>> Validators { get; set; }
public FileImporter(IWindsorContainer container) {
// the ResolveAll method does not do this
Validators = container.ResolveAll<IValidation<Patient>>("fileValidation");
}
}
I also have another class that has more validators but uses some of the same ones used in FileImporter.
public PatientService {
IEnumerable<IValidation<Patient>> Validators { get; set; }
public PatientService(IWindsorContainer container) {
// the ResolveAll method does not do this
Validators = container.ResolveAll<IValidation<Patient>>("userInputValidation");
}
}
For example I have two validators LastNameValidator and DateOfBirthValidator. LastNameValidator is used in both theFileImporterand thePatientService.DateOfBirthValidatoris only used in thePatientService` class. The implementation of these two classes are below the question.
My question is how can i wire up these two classes so that they are used as described above. And what method call should I make to resolve them?
public class LastNameValidator : IValidation<Patient> {
public bool IsValid(Patient p, ref AggregateException fail) {
var isValid = !string.IsNullOrWhitespace(p.LastName))
if (!isValid)
// update fail
return isValid;
}
}
public class DateOfBirthValidator : IValidation<Patient> {
public bool IsValid(Patient p, ref AggregateException fail) {
if (!p.DateOfBirth.HasValue) {
// update fail, can't be empty
return false;
}
if (p.DateOfBirth.Value > DateTime.Now) {
// update fail, can't be in future
return false;
}
return true;
}
}
I would consider the Typed Factory Facility. You could register your validators with the names "lastnamevalidator" and "dobvalidator". Then create a factory interface for grabbing those specific validators. You just need the interface -- the facility will do the implementation:
public interface IValidatorFactory
{
IValidator GetLastNameValidator();
IValidator GetDobValidator();
}
Now pass the IValidatorFactory to your component. This also removes the need to pass the Windsor container around (which isn't a good idea as it tightly couples your code to Windsor and makes unit testing more difficult).
Now just call the factory methods to access the particular validator each component needs.
UPDATE:
Still not clear on which part of your system is going to determine which IValidators to use, but maybe this would work. Use a marker inteface that is based on IValidator.
public interface IFileValidator : IValidator
{
}
public interface IUserInputValidator : IValidator
{
}
Now have your validators implement the marker interfaces depending on where they are going to be used -- and remember you can implement multiple interfaces so validators can be used in multiple situations. Example:
public class FileValidator : IFileValidator
{
public bool IsValid()
{
return false;
}
}
public class DobValidator : IUserInputValidator, IFileValidator
{
public bool IsValid()
{
return false;
}
}
public class LastNameValidator : IUserInputValidator
{
public bool IsValid()
{
return true;
}
}
Change the factory interface to return just the specific types of validators:
public interface IValidatorFactory
{
IFileValidator[] GetFileValidators();
IUserInputValidator[] GetUserInputValidators();
}
Now register the validators accorindg to their "type". If a validator has multiple uses, make sure to add a .Forward<> defintion for Windsor:
var container = new WindsorContainer();
container.AddFacility<TypedFactoryFacility>();
container.Register(
Component.For<IValidatorFactory>().AsFactory(),
Component.For<IFileValidator>().ImplementedBy<FileValidator>(),
Component.For<IUserInputValidator>().ImplementedBy<LastNameValidator>(),
Component.For<IFileValidator>().Forward<IUserInputValidator>().ImplementedBy<DobValidator>()
);