Teach Yourself Borland C++ in 14 Days - portal

Building Internet Applications
Table 13.1. C++Builder’s Internet components and their respective
functions.
Component Description
FTP Supports exchanging files with remote machines
THTML Supports parsing and layout of HTML data and provides a
scrollable view of the current HTML page
THTTP Provides access to the Hypertext Transfer Protocol
TNTTP Provides the ability to read and post to newsgroups
TPOP Provides access to the POP3 electronic mail protocol
TSMTP Supports sending Internet mail messages to SMTP servers
TTCP Provides access to the WinSock Transfer Control Protocol
(both client and server side)
TUDP Provides access to the WinSock User Datagram Protocol (both
client and server)
Some of these components provide access to popular Internet elements with which you’re
probably familiar. For example, if you were going to build an FTP utility, you would use the
FTP component. If you were building a newsreader, you’d use the NTTP component. If you
were constructing a Web browser (as we are today), you’d make use of the THTML control. If
you wanted to send mail over the Internet, you might make use of the POP or SMTP component.
This bevy of high-level controls makes much of the WinSock coding of yesteryear obsolete
and makes developing sophisticated Internet-related applications a snap.
Building Your Web Browser
Now that I’ve introduced you to C++Builder’s Internet components, let’s build a simple Web
browser. It’s not like the world really needs yet another Web browser; the purpose of this
exercise is to demonstrate how easy it is to put together Internet apps that would have been
major undertakings just a couple of years ago. C++Builder’s component-based approach to
development allows you to concentrate on what you want to do rather than on how to do it.
Let’s begin by starting a new project in C++Builder. Choose File | New Application from the
C++Builder menu system to initialize a new application project. When the new project is
started, you’ll be presented with a new, blank form on which you can drop components. This
form will be your Web browser. Set its Caption property to Surf and its Position property
to poScreenCenter. Before you proceed, go ahead and save the new application as Surf.CPP
and its associated form as Surf00.CPP. I suggest you use these similar yet different filenames
475
13