Question

I have a web service in asp.net and I have this model to return:

[Seriazable]
public class Package {

    public int Id { get; set; }
    public string Name { get; set; }
    public string List<Document> Documents { get; set; }

    public Package() { }
}

And in my web service I have these methods:

[WebMethod]
public Package GetPackage(int Id);


[WebMethod]
public List<Package> FindPackage();

The first method is ok (all properties are returned and it works fine), but the on second method I don’t want to expose Documents property, only the Id and Name… how can I do it?

Thanks

Answer 1

Since you don’t want the consuming client to have access to the documents, you should create a separate view model¹ class for the second method to serve. Something like this:

public class SimplePackageViewModel
{
    public int Id { get; set; }
    public string Name { get; set; }
}

You can then instantiate objects of this class using some mapping utility, for example AutoMapper, and return those instead:

[WebMethod]
public List<SimplePackageViewModel> FindPackage();
[WebMethod]
public Package GetPackage(int id);

Karel Frajtak suggested you use a similar view model object also for the package, but since they are identical that will only clutter your code – as long as the Package is a simple POCO, there is no need for an extra class. However, if you are using some O/R-mapper that keeps track of Package instances, it is wise not to expose them to the client app. Then you should instead do what Karel suggested, and create a POCO view model class for the Package as well.

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¹⁾ Some call them Data Transfer Objects (DTO). I call them View Models. I bet there are ten other names out there too – for all practical purposes, they are the same.