Please help me Run web services from information stored in a datab

[Alsi]

Hi Everyone,

I have used "Add Web Reference" for consuming different web services.

But currently I am trying to generate a generic Proxy Web Service that
will be created and populated dynamically from the entries in the database
which is my project work in a college.And I am really new in web programming,
so any help from you all will be highly appreciated.
Thank you

 

[Emil Kvarnhammar]

I can't fully understand your question.
Do you want to create a web service, that gets information from
a database and publishes the information to the consumer?

What do you mean by "generic"? Do you want the webservice
to work generally with all tables and resultsets? Normally
webservices are strictly typed, which means that you specify
the types you want to return. Of course though, it's possible to
create your own object model for representing database rows,
columns, datatypes etc.

Pls give some additional information on what you wanna achieve.

regards
Emil Kvarnhammar
http://www.ynax.com

 

[Alsi]

â–ºSorry for not writing the question in details.

My requirement is not as complicated as you had spelled out in the reply. In
fact, the database will contain the string where the WSDL file could be found
in the net. To give you an idea what string will be stored in the databse, I
will store the string such as http://ws.strikeiron.com/EmailVerify?WSDL in
the databse, read this string during the application execution.

Once I have the string that describes where I can find the Web Service, I
would like to pass this string to my Generic Proxy Class and be able to
construct this Class on the fly and use it in my application. I am currently
doing this by Adding Web Reference using Visual Studio which creates a proxy
class and lets me instantiate and use the class in my application. It works
really well but m,y professor wants me to be able to add an WSDL location
entry in the database table and be able to dynamically create the proxy class
so that I could expand the number of web services that could be invoked from
my application without making any changes in the code.

I don't know if my approach to create the proxy class dynamically from the
WSDL location string is the right way to go but that is what came to my mind.
Any alternate way of finding the Web Services from the application
dynamically without having any references in the code is all I need. I would
really appreciate if you could provide me some guidance or sample code that
does this. I am using VB .NET and new to programming.

Please send me an email at (e-mail address removed) or post a reply here. I will
be looking at this site 8-10 times a day to see if my question is replied .

Thanks a lot for your help.

Usha

 

[Alsi]

Thanks Emil for your quick response and help.
Sorry for not writing the question in details.

My requirement is not as complicated as you had spelled out in the reply. In
fact, the database will contain the string where the WSDL file could be found
in the net. To give you an idea what string will be stored in the databse, I
will store the string such as http://ws.strikeiron.com/EmailVerify?WSDL in
the databse, read this string during the application execution.

Once I have the string that describes where I can find the Web Service, I
would like to pass this string to my Generic Proxy Class and be able to
construct this Class on the fly and use it in my application. I am currently
doing this by Adding Web Reference using Visual Studio which creates a proxy
class and lets me instantiate and use the class in my application. It works
really well but m,y professor wants me to be able to add an WSDL location
entry in the database table and be able to dynamically create the proxy class
so that I could expand the number of web services that could be invoked from
my application without making any changes in the code.

I don't know if my approach to create the proxy class dynamically from the
WSDL location string is the right way to go but that is what came to my mind.
Any alternate way of finding the Web Services from the application
dynamically without having any references in the code is all I need. I would
really appreciate if you could provide me some guidance or sample code that
does this. I am using VB .NET and new to programming.

Please send me an email at (e-mail address removed) or post a reply here. I will
be looking at this site 8-10 times a day to see if my question is replied .

Thanks a lot for your help.

 

[Emil Kvarnhammar]

Hi again,

Still, I can't understand 100% clearly what your'e looking for.
I can see two possible alternatives. Please let me know if I get your point,
in any of these.

Alt. 1)
Do you want to set the URL depending on what you read from the database?

In that case it's very simple. For your proxy (e.g. EmailVerifyProxy), just
write code like this:

//assume that you've read the url from the database, and stored the url in
strUrlReadFromDatabase.
EmailVerifyProxy p = new EmailVerifyProxy();
p.Url = strUrlReadFromDatabase;

That code would make the actual location (the URL) of your webservice
dynamically.

Alt. 2)
Or do you really want to get the WSDL from the server (EmailVerify?WSDL),
and
generate proxy code on-the-fly for that WSDL-data? In that case, the easiest
way
is to use the wsdl.exe tool.
If this is the case, then you could make a class that takes the URL (for
example,
http://ws.strikeiron.com/EmailVerify?WSDL) as constructor parameter, and
then
calls wsdl.exe with that URL as input. WSDL will
Check out this link for info about wsdl.exe:
http://msdn.microsoft.com/library/e...WebServicesDescriptionLanguageToolWsdlexe.asp
If you then want to use the class that WSDL generated (that is, use it from
within the
same process as you generated the code), you'll have to compile it
first to an assembly, and of course load the assembly using Reflection.
It's a bit tricky, but it should work.



Regards
Emil Kvarnhammar