The WebHub class library includes a class called TwhWebActionEx. It is
special for two reasons:
- Whatever the component does, that action can be triggered from the web
simply by calling its name. If the component is called WebMailForm then
a WebHub page will cause the component to execute/run. In the case
of WebMailForm, which is included with WebHub, it will send an email message.
- Save-state features are included. So even though there might be
a thousand people sharing your custom application in an afternoon, each
one of them gets to use the component with their own properties set just
the way they require. Examples would be: number of search results
returned, graphics preferences, or foreign language translation.
Besides giving you the "base class" for TwhWebActionEx, WebHub also
gives you a number of derived components for special purposes. By using
these components you save yourself anywhere from hours to weeks of work
in implementing special purpose features. Here are some popular examples:
- TwhdbScan - displays a database-driven HTML table, with scrolling
and many other features.
- TwhMailForm - sends email messages including form letters with
surfer data "merged" in.
- TwhPicture - processes BMP to GIF conversions (a separate license is required from Unisys).
- TwhDropDown - create HTML drop-down boxes that save-state
- and many more!
Once you learn to program Web Action components, you have
unlocked the power of WebHub. Here is a simple HELLO, WORLD
example so you can see the syntax. This code goes on the
of the TwhWebActionEx component which has
been named waHello in this example.
procedure TfmAppSendStr.waHelloExecute(Sender: TObject);
with TwhWebAction(Sender).Response do
Send('The time is '+DateTimeToStr(now));