Refreshing a SOAP WSDL import file with Delphi

I’m consuming a web service from a Delphi desktop app and both the web service and the desktop app are being developed at the same time.   Because the WSDL generated by the web service can change, I need to refresh the service interface code that the Delphi code uses to access the web service.  It corresponds to the web references class that a .NET app would use to consume a web service.

You typically create the web service interface code by bringing up the WSDL Import Wizard from the File->New->Other menu in Delphi.  You get a dialog that prompts you for the location of the WSDL file or URL.  From the WSDL, it generates a unit with interfaces defined for the classes and objects exposed by the web service.  It creates the file with the name of the service, plus “.pas”.

It works pretty well, but if you need to refresh that file due to changes in the web service, you don’t need to use that wizard to update the file.  There is a command line tool that will generate a new output file from a specificied WSDL.  This tool is named WSDLImp.exe, and is located in the bin folder of your Delphi installation.

The typical syntax is

WSDLImp.exe -P http://localhost/somefolder/someservice.asmx?WSDL

That will generate a file named someservice.pas.  If you want to specify a different name for the file, you can use the “-=” command line parameter like this"

WSDLImp.exe -P -= http://localhost/somefolder/someservice.asmx?WSDL=myservice.pas

That will create the file myservice.pas.  Very handy if you want to use a different name than the default.  Now when you update the service interface, you can just run WSDLImp to reimport the web service interface.