Custom Property Descriptors

I will show from the beginning how to create advanced RIA applications, step by step, First defining the tools needed and how to implement them. I created an advanced  automatic DAL like EntityFramework but it doesn’t add any code and works with lambda expressions, based on Automatic Access DAL , when I didn’t know anything about MVVM.

To make automatically the fields in the database based on the fields of our model, we have to define a custom descriptor, like the following:


public class EntityDescriptionAttribute : DescriptionAttribute
{
public EntityDescriptionAttribute(String description)
{
this.DescriptionValue = description;
}
}

This descriptor allows us to define if a field will be selected, inserted, updated or deleted in the database.

Any entity in our database will inherit from:


[DataContract]
public class BaseEntity
{
[EntityDescription("ID")]
[DataMember]
public Int32 ID;

[EntityDescription("IsDeleted")]
[DataMember]
public Boolean IsDeleted;

public BaseEntity() { ID = -1; IsDeleted = false; }
}

The descriptor will be the field name in the database, and all the data will have an ID, and in this case I do not delete information, I just set the IsDeleted flag.

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