Say I have this class
public class MyObject : IObject
{
public MyObject(IObject2 object2)
{
}
}
which I resolve like:
Container.Resolve<IObject>("SomeName");
Is it possible to configure Unity so that whenever an IObject is resolved using any name, then the IObject2 will also be resolved with that same name (assuming it was registered with such a name)?
I'm looking for a way that doesn't use InjectionConstructor, as I son't want to update it for every new name I introduce.
This ought to work:
container.RegisterType<IObject2, MyObject2>("someName");
// ...
container.RegisterType<IObject, MyObject>("someName",
new InjectionConstructor(
new ResolvedParameter<IObject2>("someName")));
If you want to register more names, you could always consider packaging this little snippet into a reusable method that takes the name as an input parameter.
I don't have Unity nearby right now, so this is more or less from memory...
Related
Alright so I've been continuing to learn about classes and oop languages. And am a bit confused.
If I was to have a separate class for player stats. And in that class I have some private ints and then some functions to change them publicly.
Say I want to change and get those ints From my main class. I make an object and assign them to local variables then I can call the local variables in my main script. Then update the variable in the stat class.
It seems a little silly that I have to make a local variable as well as a separate variable in a different class.
To me it would make sense to just be able to call the separate class in a new object whenever I wanted to access the variables in the stat class but I can't...
Let me know if this isn't clear as I can try to expand more.
Thanks
Ben
You do not have to make new variables in the "main" class ....
you can just use the getters and setters through the object that you created.
Also copying variables from player stats to main class is not a good idea because now you have to maintain two copies of same data, at least until you are in scope of main class. If not handled correctly it can also cause data inconsistencies.
Assuming you are using Java, you can do this.
public class PlayerStats{
private int var1=20;
public void setVar1(int var1){
this.var1=var1
}
public int getVar1(){
return var1
}
}
public class mainClass{
PlayerStats pStats = new PlayerStats();
pStats.getVar1();
pStats.setVar1(14);
System.out.println(pStats.getVar1());
}
Thanks for that answer definately cleared things up however, in the object created in mainClass if I create the object in one function how do I use it in another function in the same class?
Depends on how and if the two functions are connected and how central that object is to your class.
If the object is very central to class :
That is, you are using it almost in all the function, your class revolves around playing with that object, then you can create it at class level something along these lines
public class mainClass{
PlayerStats pStats = new PlayerStats();
public void function1() {
pStats.setVar1(14);
System.out.println(pStats.getVar1());
}
public void function2(int x) {
pStats.setVar1(x);
System.out.println(pStats.getVar1());
}
}
If two functions are not connected :
Just make a new object inside the function scope, if possible.
This is better than creating an object at class level, because the object becomes eligible for garbage collection after the function is finished executing. Whereas, the object created at class level stays in the memory as long as the object (instance of main class) is in the memory.
If two functions are connected, i.e you are calling one function from inside the second function :
you can just pass the object as an argument, something along these lines
public class mainClass{
public void function1() {
PlayerStats pStats = new PlayerStats();
pStats.setVar1(14);
function2(pStats)
}
public void function2(PlayerStats x) {
System.out.println(pStats.getVar1());
}
}
Also google dependency injection, it is an important concept, try to use it as often as possible. It produces good decoupled and testable design
There is so much more to say, people have written books on this topic, OO Design is an art in itself.
Trying to clean up some nasty code, for which we dont have the source code. Imagine something like this:
public class Driver{
private String paramA;
private String paramB;
new Driver(HugeAndOverbloatedObject object)
{
paramA = object.getSubObject4711().getParamX();
paramB = object.getSubObject4712().getParamY();
}
}
This third library has this all over the place: tight coupling via constructors, eventhough the classes are hardly related. The rude combination of private members and forced constructor inheritance make the extension of the code virtually impossible without creating "sloppy" constructor parameter objects.
So I am trying to manipulate the classes via AspectJ and compile time weaving, so I can slim down on the constructors, to something like this:
Driver driver = new Driver("paramA", "paramB");
I think this should be possible, and I have made some progress. If I have something like this:
public aspect NewConstructor {
Driver.new(String parameterA, String parameterB){
//New Constructor Code
}
}
and run this through the weaver I actually find a new constructor in the driver, but not quite as I expected.
Issue: Unexpected third Parameter in the woven class
I was hoping I can invoke it with two parameters:
new Driver("paramA", "paramB")
Instead I need to invoke it with three parameters:
new Driver("paramA", "paramB", new NewConstructor())
Why do I need to instantiate a new instance of the aspect and pass it as an argument? Can this be prevented?
Something odd is going on here. You should not need to add the aspect as a third argument to the constructor. In fact, when I try this myself using the following class and aspect, I do not get any compile errors:
Java class:
package pack;
public class Driver {
public static void main(String[] args) {
new Driver("paramA", "paramB");
}
}
Aspect:
package pack;
public aspect NewConstructor {
public pack.Driver.new(String parameterA, String parameterB){
}
}
Are your Java class and aspect in different projects? Are you using an aspect path and/or in path? Are you using load time weaving?
If after doing a full build of your project you still see the probem, it's worth raising a bug for AspectJ.
I already have a concrete class registered in my unity container and I want to, later on, register an interface that hooks up to that class but uses the existing registration.
I can do this using the following code but it causes a resolve at registration time...
container.RegisterInstance<IMyClass>(container.Resolve<MyClass>());
Is it possible to hook the code up with all resolution done at the point the interface is resolved?
The trick is to use an InjectionFactory:
container.Register<IMyClass>(
new InjectionFactory(c => c.Resolve<MyClass>()));
It sounds like you want to create a factory type. Here, a Func delegate type is used to avoid the creation of a new custom factory type:
container.RegisterInstance<Func<IMyClass>>(() => container.Resolve<MyClass>());
Your other types can then take a dependency on this factory:
private IMyClass myClass;
public MyOtherType(Func<IMyClass> myClassFactory)
{
this.myClass = myClassFactory();
}
IUnityContainer container = new UnityContainer();
var onlyInstance = new MyClass();
container.RegisterInstance<IMyClass>(onlyInstance);
IMyClass resolved = container.Resolve<IMyClass>();
if (object.ReferenceEquals(onlyInstance, resolved))
{
Console.WriteLine("Equal");
}
This prints "Equal". This is the way I would register the instance in the first place.
In a comment above, you imply that you do not control the initial registration. That's the real issue. I would recommend going down one of the following paths (in order of preference, highest to lowest):
Create your own UnityContainer independent of the pre-registered one
Create a child container with CreateChildContainer
Use named (non-default) mappings
Is there some global state somewhere that I can access the currently-running test name?
I have tests which output files into a directory and read them back in. I'd like each test to create a directory to play in and then clean up after itself, and I don't want to push that name in (I'd have to make it unique, and then make sure each test keeps it unique; ew). I could use a GUID, but I'd like helper methods to be able to assume "this is the place where test files should be stored" without having to push that GUID around to them. Again, this augers for a global state somewhere.
Basically, I want a call like TestRunner.Current.CurrentTest.Name. Does such a thing exist?
(Assuming c#)
NUnit.Framework.TestContext.CurrentContext.Test.Name
or
NUnit.Framework.TestContext.CurrentContext.Test.FullName
or if you are really lazy and aren't driving your tests with TestCaseSource (thanks #aolszowka):
this.GetType().ToString()
I haven't upgraded to 2.5.7 yet myself, but it includes a TestContext class that seems to provide just what you're looking for: http://www.nunit.org/index.php?p=releaseNotes&r=2.5.7
Assuming one method per Test, in your NUnit code, you can use reflection to get the method name from the stacktrace.
If you write a helper method in your NUnit code called by other methods to do this file logging, you can use this syntax to check for the previous method:
string MethodName = new StackFrame(1).GetMethod().Name;
See the answers to question 44153, "Can you use reflection to find the name of the currently executing method?" for more details.
If we are using TestCaseSource tag then above solutions might not give correct answer
Try using TestContext.CurrentContext.Test.MethodName
Follow the below example
namespace NunitTests
{
public class Class1
{
static List<TestData> Data = new List<TestData>()
{
new TestData()
{
...
}
};
[Test]
[TestCaseSource(nameof(TenMBInstance))]
public void TestCase(TestData value)
{
TestContext.CurrentContext.Test.Name; //TestCase(NunitTests..TestData)
TestContext.CurrentContext.Test.MethodName; //TestCase
}
}
}
i have 2 concrete types "CategoryFilter" & "StopWordsFilter" that implements
"IWordTokensFilter".
Below is my setup:
ForRequestedType<IWordTokensFilter>().TheDefaultIsConcreteType<CategoryFilter>()
.AddInstances(x =>
{
x.OfConcreteType<StopWordsFilter>();
}
);
The problem is the run-time when structure map auto inject it on my class, bec. i have arguments with same plugin-type:
public ClassA(IWordTokensFilter stopWordsFilter, IWordTokensFilter categoryFilter)
i'm always getting CategoryFilter in my first argument but it should be stopWordsFilter.
How can i setup this in a right way? thanks in advance
There are a number of possible solutions:
1) Does ClassA need to differentiate between the filters, or does it just need to run them both? If not, you can change the constructor to accept an array, which will cause all registered instances of IWordTokensFilter to be injected:
public ClassA(IWordTokensFilter[] filters)
You can then foreach over the filters to apply them.
2) If you do need to differentiate them, because they need to be used differently, you may consider having one implement a marker interface the better describes its purpose. ClassA could then be changed to take in an IWordTokensFilter and an ICategoryFilter (or whatever you name the marker interface). Register CategoryFilter with ICategoryFilter and then both will be injected properly.
public ClassA(IWordTokensFilter stopWordsFilter, ICategoryFilter categoryFilter)
3) You can tell StructureMap explicitly how to create ClassA:
ForRequestedType<ClassA>().TheDefault.Is.ConstructedBy(c => {
return new ClassA(c.GetInstance<StopWordsFilter>(), c.GetInstance<CategoryFilter>());
});
4) You can tell StructureMap to override one of the dependencies for ClassA:
x.ForRequestedType<ClassA>().TheDefault.Is.OfConcreteType<ClassA>()
.CtorDependency<IWordTokensFilter>("stopWordsFilter").Is<StopWordsFilter>();