I work on a Peoplesoft project and I am struggling with Peoplecode.
I want to create an object with a dynamic classname within Peoplecode. Kind of like in Java. This would look like something like this :
&my_object = create My_Application_Package : Class_string_name()
&my_object.commonMethodCall();
where "Class_string_name" would be dynamic. Is this possible ?
And do I mandatoraly need to create an interface for all the concerned classes ?
Any help or advise is welcomed
Thanks
Finally, it is quite simple.
I just used CreateObject function :
CreateObject(str_class_name, create_par, . . .)
Where str_class_name either:
—identifies a class by class name
—identifies a class of OLE Automation object in the form:
app_name.object_name
Description
Use the CreateObject function to return an instance of a class. You
can use this function to access an Application Class, a PeopleCode
built-in object (like a chart), or an OLE Automation object.
If the class you are creating requires values to be passed, use the
create_par parameters to supply them, or use the CreateObjectArray
function.
Considerations Using Application Classes
You can use the CreateObject function to access an Application Class.
You would want to do this when you were programming at a high-level,
when you might not know the name of the class you wanted to access
until runtime. You must specify a fully-qualified class name. In
addition, the class name is case-sensitive.
The returned object has the type of class you specified.
Related
For example, let's say I have an interface 'IFeed' and two concrete types ('Feed1' and 'Feed2') that implement this interface. Now let's say I have a 'FeedManager' type that takes multiple parameters that will get resolved dynamically, two of which are of type 'IFeed' and I'd like both concrete type to be injected via constructor injection, not via manual resolve (I only use resolve once at the composition root). I have a feeling that I should be using a factory but I wanted to see what the proper way of doing this might be. Many thanks in advance.
If you want ALL implementations of IFeed, you can use array syntax in your constructor and then nothing special is needed at type registration time.
container.RegisterType<IFeedManager, FeedManager>();
container.RegisterType<IFeed, FeedA>("FeedA"); // The name doesn't matter
container.RegisterType<IFeed, FeedB>("FeedB"); // The name doesn't matter
Then the manager constructor...
public FeedManager(IFeed[] feeds) {...}
or if you want to add a little flare for calling the constructor directly...
public FeedManager(params IFeed[] feeds) {...}
Assuming you want to determine the actual concrete instances at runtime, you need to use named type registrations and then tell unity which one you want. So, use a factory method to construct the types required and pass those in as parameter overrides. Unity will use the overrides and resolve any remaining dependencies.
// register the types using named registrations
container.RegisterType<IFeedManager,FeedManager>()
container.RegisterType<IFeed, Feed1>("Feed1")
container.RegisterType<IFeed, Feed2>("Feed2")
Assuming your feed manager has the following named constructor parameters
class FeedManager : IFeedManager
{
public FeedManager (IFeed Feed1, IFeed Feed2, string someOtherDependency)
{
}
}
and create your feed manager:
static IFeedManager CreateFeedManager()
{
ParameterOverride feed1 = new ParameterOverride("Feed1"
,_container.Resolve<IFeed>("feed1"));
ParameterOverride feed2 = new DependencyOverride("Feed2"
,_container.Resolve<IFeed>("feed2"));
IFeedManager = _container.Resolve<IFeedManager>(feed1,feed2)
return IFeedManager;
}
Obviously this is overly simplified, but you you insert your own logic to determine which instance is to be resolved and then injected for each of the IFeed instances required by the FeedManager.
With Unity you would do this like so:
container.RegisterType<IFeed, Feed1>("Feed1");
container.RegisterType<IFeed, Feed2>("Feed2");
container.RegisterType<FeedManager>(new InjectionConstructor(new ResolvedParameter<IFeed>("Feed1"),
new ResolvedParameter<IFeed>("Feed2")));
This has now configured Unity so that when it needs to resolve a FeedManager, it will resolve Feed1 for the first parameter and Feed2 for the second parameter.
i just want to make a class that inherited from Attribute class to put attribute tags in every method in my project to write the method name , Class name that have this method , date and time of calling , parameters and method's return ( if it's return something ).
i create a table in SQL Server that will receive all log information and sign it ..
i have done all the methods & query that interact with my database ( except Date & Time method) , the only problem is i don't know how to use it with Attribute way to get the information i have mention.
If you want logging with attributes, you may use PostSharp that modifies IL during compilation of your code and puts your logging codes before/after the method that you put your custom attribute derived from PostSharp's attributes (aspects)(AOP).
I think you can not do this only by use of custom attributes, because as I know custom attributes are instantiated only when Type.GetCustomAttributes() is called. So you may have to do some reflection business for sending your logs through your attributes that I don't recommend.
Instead of attributes, you can simply use AOP through a third party tool. You can use Castle Dynamic Proxy 's interceptor.
You can also log with attributes by using Interception in Castle Windsor.
To do this, you create a class that inherits from IInterceptor, register it with your container, then you can add an attribute to any class or method you want to add the logging behaviour to.
I've written an explanation here:
http://www.paulsodimu.co.uk/Post/Aspect-Oriented-Programming-Using-Castle-Windsor
And I've created a sample on GitHub to show how its done:
https://github.com/PaulSodimu/LoggingAopCastle
If any control (e.g. a DataGrid) is cast to UIComponent, how can you get its type at runtime?
Is this possible in Actionscript?
You can use getQualifiedClassName() to get class name by the value as a string. You can use describeType() to get the full information about class. And you can use constructor property to get class itself (to instantiate new instance by existing instance). Finally you can use is operator to compare to the limited set of classes. Less recommended usage of typeof operator which is rather obsolete.
To select the right way we need to know your particular problem.
I've got a class called ArtificialIntelligenceBase from which you can create your own artificial intelligence configuration sending some variables to the constructor or you can make a class that inherits from ArtificialIntelligenceBase and in the constructor of this new class just call the function super() with the parameters of the configurations.
I've also created some examples of artificial intelligences in classes, AIPassive, AIAgressive and AIDefensive. Obviously all of them inherits from ArtificialIntelligenceBase.
The point is that there're only few public functions in the base class. The variables in the base class are read only and the non public functions are protected in case you need to apply some modifications on them when created another pre-defined AI.
You can also create another AI just calling the base class sending some parameters in the constructor like this: new ArtificialIntelligenceBase(param1, param2, param3, param4);
I've tought about make the classes as a singleton because the classes can never change and once setted, their variables never change.
The question is: Is the singleton the best pattern to do this? Because I'm not sure.
PD: You don't need to explain any patter, just mention the name and I'll search for how it works
PPD: I'm developing in AS3. Just in case it helps
Thanks
In general, singletons are evil. I don't see any reason in your case to use a singleton, either. It sounds like you're using your own version of a factory method pattern (using a constructor somehow?) or maybe a prototype (I don't know AS3 one bit), but if you're looking for other patterns a couple of other ones are abstract factory and builder.
You don't need to use the singleton pattern to limit yourself to using only one instance per type of class, though. It doesn't help avoid redundancy.
Is there any way to 'dynamically'/reflectively/etc create a new instance of a class with arguments in Scala?
For example, something like:
class C(x: String)
manifest[C].erasure.newInstance("string")
But that compiles. (This is also, rest assured, being used in a context that makes much more sense than this simplified example!)
erasure is of type java.lang.Class, so you can use constructors (anyway you don't need manifest in this simple case - you can just use classOf[C]). Instead of calling newinstance directly, you can at first find correspondent constructor with getConstructor method (with correspondent argument types), and then just call newInstance on it:
classOf[C].getConstructor(classOf[String]).newInstance("string")