Defining interface

Question

I have a datamodel used by several applications, which now I need to use by other developers outside the team. The model must be made incomplete for developers.

I wonder how I best approach this: my current approach is to create a new project that simply copies the original model and includes only the requested properties.

eg

namespace Model { public class Car { private double m_speed; private FuelType m_fuelType; public double Speed { get { return m_speed; } set { m_speed = value; } } public FuelType FuelType { get { return m_fuelType; } set { m_fuelType = value; } } } } 

In my Lite model, I only want to show speed:

 using Model; namespace ModelLite { public class Car { private Model.Car car = new Model.Car(); public double Speed { get { return this.car.Speed; } set { this.car.Speed = value; } } } } 

Since the model is large, this involves a lot of duplication. Maybe there is a better alternative?

thanks

Answer 1

Take a look at Martin Fowler's work on Application Facades and Facade Image

Answer 2

There is no solution to this problem. If different developers are only allowed partial access to the fields, you will need to create different channels for different developers.

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Although your model seems wrong to me, you can, however, do this:

• Creating a single feed object that has all the properties, the main object also has
• Create an attribute like:

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  class FeedSecurityAttribute : Attribute { public FeedSecurityAttribute(params string[] rights) {} } 

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• Add annotations to the feed’s properties, indicating who has access to this property, for example [FeedSecurity("piet", "klaas")] string MyProperty { get;set; } [FeedSecurity("piet", "klaas")] string MyProperty { get;set; }
• Fill your feed object from the business object automatically using some reflection and expression trees, and check if the user has access to this property, otherwise ignore it.

Answer 3

Perhaps you can use several interfaces

 public interface ICarBasic { double Speed { get; set; } } public interface ICar : ICarBasic { FuelType FuelType { get; set; } } 

Or write your entire base object as base classes. Inherit from them to make complete classes using the new assembly. Providing developers with a third-party project, only assembly with base classes can solve your problem.

Assembly 1 (for other developers)

 using Model; namespace ModelLite { public class Car { private Model.Car car = new Model.Car(); public double Speed { get { return this.car.Speed; } set { this.car.Speed = value; } } } } 

Unit 2 (fully functional)

 using ModelLite namespace Model { public class Car : ModelLite.Car { private FuelType m_fuelType; public FuelType FuelType { get { return m_fuelType; } set { m_fuelType = value; } } } } 

Only give assembly 1 to other developers.