Tuesday (6/20/2006)

 I gave a assigned a task to my developer.  What I asked her was to create a code so when I go call different webservices assuming like Google search, MSN search, Amazon search, yahoo search, etc., each provider might have different wsdl definitions for their webservice, but I should not change my code as and when I add a new search provider.  Essentially my search code should be like the following

string [] searchResults = searchProvider.Search(”Joke of the day”);

She tried for couple days and finally came back and said that how can she write a code that can not be changed when she adds a new provider.  Because google's search wsdl may be like Google.doGoogleSearch, while Msn may be like Msn.SearchEverywhere and yahoo may be like yahoo.SearchUniverse, etc.,

After thinking about the solution I decided to write the code myself.  I always knew generating .cs file using WSDL gives more flexibility but never really changed the .cs file to make use of it.  Hey, finally I did...

Friday (6/23/2006)

I created another project called IGateway which has a public interface

namespace myInterfaces;

public interface IGateway

{

     string [] Search(string What);

}

 

I put all the Gateways in a separate project called SearchProviders and added reference to IGateway project to it.

I call .cs file generated by WSDL as Gateway (GoogleGateway.cs, MSNGateway.cs, YahooGateway.cs)

Now I edit the GoogleGateway.cs to add the following

using myInterfaces;

 

I put all the WSDL files in a new project called SearchGateways

change the class definition generated by WSDL to implement IGateway interface

public class GoogleSearchService : System.Web.Services.Protocols.SoapHttpClientProtocol, IGateway {

Now add a public method that implements Search Function from IGateway like this

public string[] Search(string SearchWhat)

{

           return this.doGoogleSearch(SearchWhat);

}

Obviously I have oversimplied the sample function here because doGoogleSearch has more funtions and it does not return a string array as parameter, but I guess you can figure that out.

All I need to do in my actual application that needs to perform a search I need to use reflection to create an object in runtime of type IGateway (AssemblyName and TypeName can be read from configuration file) to perform search.  If I add a new SearchProvider I need to generate gateway file for that provider and change only that file and recompile only my SearchGateways project and copy the assembly.

Saturday (6/24/2006)

Family out on trip, sleep long hour, wakeup, eat, sleep, wakeup, eat, sleep...  you get the idea for the weekend