Web Service with base class

[rupertgalea]

I have a bunch of web services that are used to return data. All of the
methods access a DB to get the data. Ideally I would like to have them
inherit from a base class that takes care of the DB connection and
exception logging.

By default in VS.NET all web service classes inherit from
System.Web.Services.WebService. My understanding is that the main
benefit of this is you get access to the Application and Session
objects. But a web service does not need to inherit from this class to
work. VS.NET generates code that overrides the Dispose method of this
inhertited class so I can not even compile without inheriting.

So as I see it I could
A) Figure out how to make my web service classes work without
inheriting from System.Web.Services.WebService and then inherit from a
base class that takes care of DB connections and logging.

B) Use Microsoft's Data Access Application Block to take care of DB
connection and paramter caching and find another way to deal with
logging.

Anyone have any recommendations? Is there another way to do this? How
can I achieve A)

Thanks in advance,
Rupert

[Tom Porterfield]

On 26 Jan 2005 17:25:28 -0800, ru*********@hotmail.com wrote:

I have a bunch of web services that are used to return data. All of the
methods access a DB to get the data. Ideally I would like to have them
inherit from a base class that takes care of the DB connection and
exception logging.

By default in VS.NET all web service classes inherit from
System.Web.Services.WebService. My understanding is that the main
benefit of this is you get access to the Application and Session
objects. But a web service does not need to inherit from this class to
work. VS.NET generates code that overrides the Dispose method of this
inhertited class so I can not even compile without inheriting.

So as I see it I could
A) Figure out how to make my web service classes work without
inheriting from System.Web.Services.WebService and then inherit from a
base class that takes care of DB connections and logging.

B) Use Microsoft's Data Access Application Block to take care of DB
connection and paramter caching and find another way to deal with
logging.

Anyone have any recommendations? Is there another way to do this? How
can I achieve A)

I recommend you pursue B. An object should know how to do one thing, and
do it well. The webservice class should know how to process and respond to
webservice requests. That's it. If you need to access a database, then
you should have another class or set of classes that know how to do that,
and they should do it well. If you need to do some logic processing on the
data after it is retrieved from the database and before the webservice
returns it to the caller, then that should be in another class that just
knows how to do the business logic processing.
--
Tom Porterfield

[HG]

Hi

I would go for option 2, too.

But use the business delegate pattern wthin the webMethod.
That way you can delgate your call to another class (interface, maybe).

I have done this with an interface as the delegate and a factory that
instatiates the correct instance of class which supports delegate interface.
Gives you the opportunity to change the actual implementation class while
still using the same interface to your delegate.

Regards

Henrik
http://websolver.blogspot.com

<ru*********@hotmail.com> skrev i en meddelelse
news:11*********************@z14g2000cwz.googlegro ups.com...

I have a bunch of web services that are used to return data. All of the
methods access a DB to get the data. Ideally I would like to have them
inherit from a base class that takes care of the DB connection and
exception logging.

By default in VS.NET all web service classes inherit from
System.Web.Services.WebService. My understanding is that the main
benefit of this is you get access to the Application and Session
objects. But a web service does not need to inherit from this class to
work. VS.NET generates code that overrides the Dispose method of this
inhertited class so I can not even compile without inheriting.

So as I see it I could
A) Figure out how to make my web service classes work without
inheriting from System.Web.Services.WebService and then inherit from a
base class that takes care of DB connections and logging.

B) Use Microsoft's Data Access Application Block to take care of DB
connection and paramter caching and find another way to deal with
logging.

Anyone have any recommendations? Is there another way to do this? How
can I achieve A)

Thanks in advance,
Rupert

[Dilip Krishnan]

Hello ru*********@hotmail.com,
As I see it you need all web services to use the same database code via
inheritance [0]. Not a bad thing, but you will see the impact of that decision
when the data access methods change. All the services will potentially need
to change purely because of the fact they are inherited. Consider the option
B you suggested (composition) [0]. Use DAAB if you add a 'non-breaking' change
to DAAB or alter the implementation you dont need to recompile all your services,
just replace your DAAB assembly.

the example is in java but its an oo concept ;)
[0] - http://www.javaworld.com/javaworld/j...echniques.html
HTH
Regards,
Dilip Krishnan
MCAD, MCSD.net
dkrishnan at geniant dot com
http://www.geniant.com

I have a bunch of web services that are used to return data. All of
the methods access a DB to get the data. Ideally I would like to have
them inherit from a base class that takes care of the DB connection
and exception logging.

By default in VS.NET all web service classes inherit from
System.Web.Services.WebService. My understanding is that the main
benefit of this is you get access to the Application and Session
objects. But a web service does not need to inherit from this class to
work. VS.NET generates code that overrides the Dispose method of this
inhertited class so I can not even compile without inheriting.

So as I see it I could
A) Figure out how to make my web service classes work without
inheriting from System.Web.Services.WebService and then inherit from a
base class that takes care of DB connections and logging.
B) Use Microsoft's Data Access Application Block to take care of DB
connection and paramter caching and find another way to deal with
logging.

Anyone have any recommendations? Is there another way to do this? How
can I achieve A)

Thanks in advance,
Rupert

[HG]

Or even better...You composition is an Interface.

That way you can change the underlying implementation of the class

Regards

Henrik
http://websolver.blogspot.com

"Dilip Krishnan" <dk*******@NOSPAM.geniant.com> skrev i en meddelelse
news:22**********************@msnews.microsoft.com ...

Hello ru*********@hotmail.com,
As I see it you need all web services to use the same database code via inheritance [0]. Not a bad thing, but you will see the impact of that decision when the data access methods change. All the services will potentially need to change purely because of the fact they are inherited. Consider the option B you suggested (composition) [0]. Use DAAB if you add a 'non-breaking' change to DAAB or alter the implementation you dont need to recompile all your services, just replace your DAAB assembly.

the example is in java but its an oo concept ;)
[0] - http://www.javaworld.com/javaworld/j...echniques.html
HTH
Regards,
Dilip Krishnan
MCAD, MCSD.net
dkrishnan at geniant dot com
http://www.geniant.com

I have a bunch of web services that are used to return data. All of
the methods access a DB to get the data. Ideally I would like to have
them inherit from a base class that takes care of the DB connection
and exception logging.

By default in VS.NET all web service classes inherit from
System.Web.Services.WebService. My understanding is that the main
benefit of this is you get access to the Application and Session
objects. But a web service does not need to inherit from this class to
work. VS.NET generates code that overrides the Dispose method of this
inhertited class so I can not even compile without inheriting.

So as I see it I could
A) Figure out how to make my web service classes work without
inheriting from System.Web.Services.WebService and then inherit from a
base class that takes care of DB connections and logging.
B) Use Microsoft's Data Access Application Block to take care of DB
connection and paramter caching and find another way to deal with
logging.

Anyone have any recommendations? Is there another way to do this? How
can I achieve A)

Thanks in advance,
Rupert

[Dilip Krishnan]

Hello HG,

Or even better...You composition is an Interface.

IMO If the idea is to reuse code that that wouldnt make sense. then
every class has to implement this interface. In general you need to seperate
layers of responsibility, so the rule of is, if your class is a math web
service. Any authentication function of that service should be in a seperate
'helper' class implementation (with its own inheritance heirarchy i.e. IAuthentication
interface WindowsAuthentication Implementation etc) and the service should
be composed of these 'helpers' That way your service can chance independent
of the authentication mechanism. Makes sense?

HTH
Regards,
Dilip Krishnan
MCAD, MCSD.net
dkrishnan at geniant dot com
http://www.geniant.com

[rupertgalea]

Thank you all for your replies.I am new to the OO world and these
replies are helpful. I am not familiar with the business delegate
pattern but I will look into it.

I had read articles such as this
http://www.c-sharpcorner.com/Tutoria...3TierAppPA.asp
but of course this was no written with the DAL being web services
(client choice) in mind.
Rupert