Delphi - Indy (IDHTTP) Keep Session

Answer 1

I don't see where you instantiate CookieManager, but that's where you should keep track of the session. The server will send some cookie that represents the current session, and all further requests that you send to the server should include that cookie so the server knows which session to use.

You'll have to either keep the cookie-manager object around for the duration of the session, or you'll have to save its data somewhere else and then re-load it each time you create a new cookie-manager object. I'd prefer the former. In fact, you might consider keeping the entire HTTP object around.

Answer 2

As Rob said your TIdCookieManager is key for maintaining a Cookie based session. The TIdCookieManager could be created in a datamodule's create event or the mainforms OnCreate() event and then set every time you create a IdHTTP component.

Answer 3

As you mentioned in your comments, you are creating CookieManager in OnCreate event-handler, so that when TForm1.webSession is called, CookieManager is available, but in the finally block of TForm1.webSession you are freeing CookieManager, so once you leave TForm1.webSession method, CookieManager is out of memory. So, next time TForm1.webSession is called, CookieManager is Nil, and no cookie is saved for you.

There are two other notes that are not related to your question, but are related to your source code:

1- Your method is returning AnsiString, but you are using Utf8ToWideString for assigning value to Result variable. Utf8ToWideString returns WideString, so compiler has to convert WideString to AnsiString, and not only this reduces the performance, but also it loses the unicode characters in the returning string. You should change your method signature to return either String (D2009 & D2010) or WideString (Older versions of Delphi).

2- You don't need to check if SStream, AntiFreeze, or HTTPCon are assigned in the finally block. You can simply call the Free method, or use FreeAndNil procedure.

Regards