How to generify a method when T can be multiple new () Types?

» chash » How to generify a method when T can be multiple new () Types?

By : mikikoon

Date : November 26 2020, 04:01 AM

To fix this issue Assuming that RegionModel & SecteurDActiviteModel will share the Id & Nom properties, I would suggest you create an ISomeInterface and implement it on your types, RegionModel : ISomeInterface. It is not necessary to return the actual type like you are doing - result = new SimpleGenericModel(); - the type will be known at compile time by the T you pass to the method.
With the new interface you can constraint the method even more like this:

code :

public T GetSimpleModelFromMultiNode<T> (FicheArticleViewModel model, string alias) where T: new(), ISomeInterface,

public T GetSimpleModelFromMultiNode<T>(string model, string alias) where T : ISomeInterface, new()
{
    var listeItems = CurrentPage.GetPropertyValue<IEnumerable<IPublishedContent>>(alias);
    var result = new T();
    if (!CurrentPage.HasValue(alias)) return result;
    foreach (var item in listeItems)
    {
        result.Id = item.Id.ToString();
        result.Nom = item.Name;
    }
    return result;
}

public interface ISomeInterface
{
    int Id { get; set; }
    string Nom { get; set; }
}

public class RegionModel : ISomeInterface
{
    //Your implementation goes here
}

public class SecteurDActiviteModel : ISomeInterface
{
    //Your implementation goes here
}

public IEnumerable<T> GetSimpleModelFromMultiNode<T>(string model, string alias) where T : ISomeInterface, new()
{
    var listeItems = CurrentPage.GetPropertyValue<IEnumerable<IPublishedContent>>(alias);   
    if (!CurrentPage.HasValue(alias)) return Enumerable.Empty<T>();
    return listeItems.Select(i => new T 
    {
        Id = i.Id.ToString(),
        Nom = i.Name,
    });
}

public T GetSimpleModelFromMultiNode<T>(string model, string alias) where T : ISomeInterface, new()
{
    var listeItem = CurrentPage.GetPropertyValue<IEnumerable<IPublishedContent>>(alias).FirstOrDefault();   
    if (!CurrentPage.HasValue(alias)) return new T();

    if (listeItem == null)
    {
        return new T();
    }

    return new T
    {
        Id = listeItem.Id.ToString(),
        Nom = item.Name
    };
}

Share :

Hook method with multiple types

By : codertcvatandasi

Date : March 29 2020, 07:55 AM

hope this fix your issue I would suggest looking for a library to do this for you. But assuming you need to write it your self, I think what you want is generics

code :

public abstract class XMLExporter<T> {
    public void generateXML(T object) throws ParserConfigurationException, TransformerException{
        Document doc = createDomDoc();
        fillXML(doc, object);
    }

    public abstract void fillXML(Document doc, T object) throws TransformerException;
}

public class CustomerExporter extends XMLExporter<Customers> {

}

How to proper generify a method which returns an instance using Reflection API?

By : John Jumper

Date : March 29 2020, 07:55 AM

With these it helps I want to retrive an instance by Class type. But for now I struggling with generics. My code doesn't work and I don't know actually why. Here it is: , Try this:

code :

public class Main {
    public static void main(String[] args) throws Exception {
        Provider provider = new Provider("prop");
        AbstractHolder obj = provider.create(DefaultHolder.class);
        System.out.println(obj.getProperty());
    }
}

public class Provider {
    private String property;

    public Provider(String property) {
        this.property = property;
    }

    public <T extends AbstractHolder> T create(Class<T> type) throws InstantiationException, IllegalAccessException, IllegalArgumentException, SecurityException, InvocationTargetException, NoSuchMethodException {
        return type.getConstructor(property.getClass()).newInstance(property);
    }
}

Multiple Argument Types for HTTpPost Method in ASP.NET MVC Controller Method

By : Alessandro Brugnetti

Date : March 29 2020, 07:55 AM

wish helps you As Venkat indicated, creating a view model is your best option but you can also add additional parameters to your POST method

code :

[HttpPost]
public ActionResult Index(PostedColumns postedColumns, string InputGridRowCount, string InputGridRowCountDST, string InputGridRowCountDSR)
{
  ...

public ActionResult Index(PostedColumns postedColumns)
{
  string inputGridRowCount = Request.Form["InputGridRowCount"];
  ....

Multiple return types from a method

By : Couponsnip

Date : March 29 2020, 07:55 AM

Any of those help You could design a solution around trait, but it would probably be much more work than simply adapting your current solution slightly:

code :

struct DateBased{
    series: String,
    date: Date
}

struct SeasonBased{
    series: String,
    season: i32,
    episode: i32
}

enum ParsedFile{
    Date(DateBased),
    Season(SeasonBased),
    // etc
}

fn _populate_datebased(file: DateBased) -> Result<PopulatedFile, TvdbError>;

fn _populate_seasonbased(file: SeasonBased) -> Result<PopulatedFile, TvdbError>;

fn populate(f: ParsedFile) -> Result<PopulatedFile, TvdbError> {
    return match f {
        ParsedFile::Date(d) => _populate_datebased(d),
        // ...
    }
}

How to generify the return type of a method that returns the object its called from

By : mehmet

Date : March 29 2020, 07:55 AM

hope this fix your issue You can add a type to the SuperClass declaration and use it in the returned type of the setName() method. It will force all inherited subclass to return the type declared in their extending declaration to SuperClass.
But to achieve it you should cast this to T in setName().

code :

public class SuperClass<T extends SuperClass<T>> {
    private String name;

    public T setName(String name) {
      this.name = name;
      return (T) this;
    }
}

public class SubClass extends SuperClass<SubClass> {
     ...
    public void setId(int i) {
       ...
    }
   ...
}

SubClass subclass = new SubClass();
subclass.setName("Some Name").setId(0);

public class SuperClass {
    private String name;

    public SuperClass setName(String name) {
      this.name = name;
      return this;
    }
}

public class SubClass extends SuperClass {

    @Override
    public SubClass setName(String name) {
       super.setName(name);
       return this;
    }

    public void setId(int i) {
       ...
    }
}