You no longer have to depend on the web.config file (the
application’s configuration file) for defining roles in your application. With
ASP.NET 2.0 around, you have support for Membership and Role provider classes,
like, the SqlMembershipProvider and SqlRoleProvider. However, the only
constraint is that these are designed to work with SQL Server only. No worries;
you can extend these classes to create your own custom provider implementations
with support for any data store. We would learn more on Providers and their
types in the sections to follow.
The ASP.NET Provider Model provides a pluggable architecture
for working with providers. You can have the flexibility of using the custom
providers; you can even implement your own providers in your applications. Well,
what is a provider, anyway? The applications need some way of storing states,
either in the temporary main memory or in a persistent manner in the database. "A
provider is a software module that provides a uniform interface between a
service and a data source. Providers abstract physical storage media, in much
the same way that device drivers abstract physical hardware devices."
The Membership and the Role Management Providers follow the
provider pattern through the usage of an interface for a contract based
approach. The base class for all the providers in such a pattern is the
ProviderBase abstract class. All the other providers are actually inherited
from this ProviderBase abstract class. The MembershipProvider and the
RoleProvider classes that inherit the ProviderBase class are also abstract
classes. David Hayden says, "the theory of the pattern is that it allows
us to define a well-documented, easy-to-understand API, such as our new Whidbey
Membership API's, but at the same time give developers complete control over
the internals of what occurs when those API's are called."
Objectives of the ASP.NET 2.0 Provider Model
The following lists the basic objectives of the ASP.NET 2.0
Provider Model.
·
Facilitate designing and developing custom providers seamlessly
·
Promotes flexibility, re-usability and extensibility in ASP.NET
state storage
Benefits of the ASP.NET 2.0 Provider Model
The Provider Model offers benefits in more ways than one.
These are as follows.
·
It can be used with the default implementation and customized too.
·
Provides a distinct isolation of code and the back-end
implementation.
·
Facilitates isolation of tasks within the project team members.
The ProviderBase class
The following is the list of the methods and properties of
the ProviderBase class in the ASP.NET 2.0 Provider Model.
·
Name
·
Description
·
Initialize()
·
ProviderBase() This is the constructor for the ProviderBase
class.
The ProviderBase class is present in the
System.Configuration.Provider namespace. This class contains two properties and
two methods. The following is the source code for this class.
Listing 1
public class ProviderBase
{
public virtual string Name
{
get;
}
public virtual string Description
{
get;
}
public virtual void Initialize(string name, NameValueCollection config);
} The "Name" property implies the name of the
provider while the "Description" property relates to the description
of the provider.
We will discuss more on the various providers in the ASP.NET
Provider Model in the sections that follow.
