I have a class and interface is implemented as below :
Class1<T> : IClass1<T>
now I am creating the property in Class2 :
Public IClass<?> MyClassProperty {get; set;}
what should be the type I need to give to this generic property , so I can assign it from the different class3.
Please suggest me.
Have you tried object? After that you can get the real type with typeof(value) (value is available in set)
Related
I am reading up on creating class factories here: https://rubberduckvba.wordpress.com/2018/04/24/factories-parameterized-object-initialization/ and I am confused why they are making the implemented functions private, wouldn't we want them to be public so we can access them?
VERSION 1.0 CLASS
BEGIN
MultiUse = -1 'True
END
Attribute VB_Name = "Something"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Option Explicit
Private Type TSomething
Bar As Long
Ducky As String
End Type
Private this As TSomething
Implements ISomething
Public Function Create(ByVal initialBar As Long, ByVal initialDucky As String) As ISomething
With New Something
.Bar = initialBar
.Ducky = initialDucky
Set Create = .Self
End With
End Function
Public Property Get Self() As ISomething
Set Self = Me
End Property
Public Property Get Bar() As Long
Bar = this.Bar
End Property
Friend Property Let Bar(ByVal value As Long)
this.Bar = value
End Property
Public Property Get Ducky() As String
Ducky = this.Ducky
End Property
Friend Property Let Ducky(ByVal value As String)
this.Ducky = value
End Property
Private Property Get ISomething_Bar() As Long
ISomething_Bar = Bar
End Property
Private Property Get ISomething_Ducky() As String
ISomething_Ducky = Ducky
End Property
Also, why do you need to provide get and let properties for public variables in an interface?
They should be Private.
The reason is because how interfaces work in VBA: the Public members of a class module define its default interface. That means the public members of Class1 define what members Class2 must implement if it Implements Class1.
So if you make Class1_DoSomething public, then you're exposing that member on the default interface of Class2, and that's... not pretty at all.
What interface you access an object with, is determined by how you declare it.
Dim thing As Class1
Set thing = New Class1
If thing is or implements Class1, then the code after this declaration can invoke all the members exposed by the default interface of Class1 (i.e. its public members).
If Class1 implements ISomething and we declare it like this:
Dim thing As ISomething
Set thing = New Class1
Now the members we get to work with are the members defined by the public members of the ISomething class/interface.
When you implement an interface or handle events, you should never manually type the signatures; instead, pick the interface (or event provider) from the upper-left dropdown in the code pane, then pick a member from the upper-right dropdown: the VBE automatically creates the correct procedure with the correct signature, and it's always going to be a Private member - rule of thumb, anything that has an underscore in its name in VBA has no business being Public
As for why you must supply Get and Let accessors for what you defined as a public field (/variable) on an interface class... Fields are implementation details, they should never be Public in the first place. Objects expose properties, not fields - keep fields for the private internal state of the implementing class.
The reason is technical: VBA code gets compiled into a COM type library, and that library sees your public variable and says "that's going to have to be a PUT and a GET method", and the VBA code implementing that interface thus needs to implement a property for every public field, because public fields compile down to properties.
This does have interesting implications with regards to the practice of exposing a public field on a class module (breaks encapsulation vs compiles down to a property anyway!), but that is a whole other discussion.
I have the following classes:
public class A{}
public class AA : A {public int aa{get;set;}}
public class AAA : A {public int aaa{get;set;}}
public class B{}
public class BB : B {public int bb{get;set;}}
public class BBB : B {public int bbb{get;set;}}
and this is my mapping:
Mapper.CreateMap<A,B>().include<AA,BB>().include<AAA,BBB>();
Mapper.CreateMap<AA,BB>();
Mapper.CreateMap<AAA,BBB>();
I was under the assumption that automapper will understand the hiearchy and map the appropriate derived class. But i wasn't able to get it with the codes below. The mapped entities are always the base class, in this case - B.
Please note I have a Repository factory which will determine the return type of GetAll().
var list = myRepo.GetAll() //this returns IEnumerabe<AA> or IEnumerable<AAA>
var newlist = Mapper.Map<IEnumerable<B>>(list); //I wanted to use "B" here due to the fact I will have many inherited classes of B. I don't want to restrict to a specific child class of B.
OK. The codes above should work. Unfortunately, I was using automapper 4.1.1 and there was a bug -https://github.com/AutoMapper/AutoMapper/issues/819.
The data being returned from a stored procedure has 3 columns of repeating data:
Name | Address | PhoneNumber | UniqueCol1 | UniqueCol2
Ideally I want my model to show that there is repeated data by only storing the values once and have a collection of the unique data.
public class MyViewModel
{
public string Name {get;set;}
public string Address {get;set;}
public string PhoneNumber {get;set;}
public List<MyModel> UniqueData {get;set;}
public class MyModel
{
public string UniqueCol1 {get;set;}
public string UniqueCol2 {get;set;}
}
}
This means I want to map a collection of results to a single object of MyViewModel:
return Mapper.Map<List<StoredProcedureObject>, MyViewModel>(result);
This is where I get my error as I assume I have some configuration that I need to do:
Mapping types:
List`1 -> MyViewModel
Any ideas on the missing step to get this to work?
Automapper is only able to flatten your structure into something simpler. But it's not possible to map a simple class to something more specific.
I would suggest to take only the first entry in your table to fill your base fields like Name, Address, PhoneNumber and iterate over your results to fill your UniqueData List.
I don't see an easier way, because with each possible mapping and without using seperate loops you will get your base data multiple times.
If you don't mind to use another tool, maybe you will have a look at ValueInjecter. I heard you can use this tool for two-way-mappings.
In Micro Focus managed Cobol, how can we set value of a method attribute?
Viz. In C# we do
[OperationContract]
[WebGet(ResponseFormat = WebMessageFormat.Json)]
public override string[] Method
So in Cobol we declare the method as
method-id MethodName public
attribute OperationContractAttribute
attribute WebGetAttribute.
But how do we set ResponseFormat = WebMessageFormat.Json ?
Similar (but not identical) to C#. The biggest difference is that the keyword 'property' has to be used before the property name.
method-id MethodName public
attribute OperationContractAttribute
attribute WebGetAttribute(property ResponseFormat = type WebMessageFormat::Json).
I have XML file which needs 3 attributes in an element. How can make the order of street, zip and city attribute as I wanted?
<address street="Big Street" zip="2012" city="Austin">
</address>
#XmlType(name="Street)
#XmlRootElement(name = "Street")
public class Street {
#XmlAttribute
private String name;
#XmlAttribute
private String type;
... set and get method
}
Anecdotally, the attributes seem to be in reverse order than they are mentioned in code. In my case, I'm using two variables (name & value) and I had to declare them as:
// The inverse order of name & value seems to make them render in XML in name/value order
#XmlAttribute
protected String value;
#XmlAttribute
protected String name;
When the XML is generated, it results in the following:
<attribute name="nameValue" value="valueValue"/>
You can use #XmlAccessorOrder(has predefined values) or #XmlType(Only works for properties) to govern the ordering.
Samples
Edit :
For custom ordering JAXB specification doesnt provide anything, but you can do if your JAXB provider provides you some features.
Found this link where it speaks about ordering using EclipseLink JAXB.