More of this Feature • Pg 1: Intro to web-broker • Pg 2: Using this tutorial • Pg 4: Web Actions • Pg 5: The first ISAPI app • Pg 6: TWebRequestObject • Pg 7: Request-responding • Pg 8: TPageProducers • Pg 9: Cookies made easy • Pg 10: Stateless HTTP • Pg 11: DB enabled apps • Pg 12: FAQ • Pg 13: DB apps - Part 1 • Pg 14: DB apps - Part 2 • Pg 15: DB apps - Part 3

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Related Resources • Internet programming • CGI and ISAPI with Delphi

Before we actually start programming, let's take a brief look at how to start an ISAPI application and what Delphi gives us.

To start a new ISAPI project, in the File menu, click on New and then choose Web Server Application.

Delphi will then present you with a choice of three types of web server applications. In our case we are going to choose the default (ISAPI/NSAPI).

Once you click on Ok, a new project will be opened. By default a new form is created. This form is the main starting point of your ISAPI application. It is a TWebModule. As mentioned in the previous chapter, the TWebModule consists of a TDataModule + TWebDispatcher. The first thing you will see is that, as with datamodules, the webmodule has very few properties and events. In particular, it consists of the following:

·Actions These are the WebActions. We will take a look at them later.
·Name, OldCreateOrder,Tag Nothing new. Same as other component properties.

·AfterDispatch This event is fired after a call has been made to one of the Webactions
·BeforeDispatch This event is fired before a call has been made to one of the Webactions
·OnCreate/OnDestroy As with other forms, you have the OnCreate/OnDestroy events

   WebActions: The heart of the application
It's true. Without the Webactions, you couldn't really do much of an ISAPI application. Let's see how these webactions work.

Every request made by the client (in our case normally a web browser) is a standard HTTP request. To make things easier, Delphi brings you the power of the TWebDispatcher. What this does is translate the HTTP request to a web action. Imagine the web action as an entry point to your DLL, like any other DLL you create and export the functions, web actions have a similar way of working.

procedure TWebModule1.WebModule1WebActionItemAction
(Sender:TObject; Request: TWebRequest;
Response: TWebResponse; var Handled: Boolean);
begin

end;

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