Creating
Dynamic /
Compatible Web Sites
Making Your
Site Dynamic
Client Side (Browser) Programming
You
have certainly heard the names of the programming languages used
for client side programming — JavaScript, Java and
ActiveX have been the talk of the web for some time. These languages
allow you create some glitzy and entertaining pages. Some of these
are listed below.
-
Smooth animated graphics.
-
Scrolling text.
-
Custom text in the browser's status bar.
-
Floating images.
-
Current (and constantly updated) date and time.
A drawback is that not all browsers can properly interpret and
run the programs. JavaScript is not the same on Netscape and Internet
Explorer, and each version of a browser has a subset of what it
will recognize. Java is very much a changing technology. Even
the courts had to get involved to try to make it compatible from
one browser to another. Java is very CPU intensive compared to
straight HTML or even JavaScript Pages. Although we've all heard
about each company trying to make their version of JAVA the standard
and thus making it non-compatible with you other browser. Older
versions of those browsers may or may not be Java enabled. Internet
Explorer version 4.0 is currently the only browser that will reliably
interpret and run sophisticated ActiveX programs.
Furthermore,
the browser's ability to run JavaScript, Java, and ActiveX may
be disabled by the user.
If
you desire the great things client side programming can give you,
please be aware that not all your visitors will be able to see
the content. An alternate display should be available and automatically
presented — which, in many cases, requires client side programming
to accomplish.
An
advantage with client side programming is that, in most cases,
the entire program loads into your browser. This may allow you
to use/run the web page without being connected to the Internet.
Some visual effects can currently be produced only with client
side programming.
Server Side (CGI) programs:
In contrast to client side programs, virtually all browsers, and
all their versions, are compatible with CGI. CGI means "Common Gateway
Interface" and is a standard method for browsers and servers to
communicate with each other.
So
long as the standard method (protocol) is followed, it doesn't
matter which browser is asking for information or what software
the server is running that will provide the answers. The server
can run any program, written in any language that can run on its
operating system platform.
Perl
is one of the most common CGI programming languages because the
same script can be used on all popular platforms — provided only
that the interpreter/compiler is already resident on that system.
Most public Internet servers set up for CGI have both Perl 4 and
Perl 5 resident because of its popularity.
It
is apparently unlimited when it comes to applications that fit
within the protocol. CGI is used for
-
Guest books
-
Forums
-
Creating web pages dynamically
-
Requesting information
-
Mailing systems
-
Maintaining mailing lists
-
Surveys and tests
-
Presenting and/or manipulating database contents
-
Creating graphics dynamically
-
Visitor tracking and presenting statistics
-
Shopping carts
-
Password verification and/or updating
-
Message boards
-
Auctions
CGI can even be used (as examples) to launch a program on the
server, mail a letter, and then return a browser page indicating
that all jobs have been completed.
Custom Programming
If you have done some programming or are proficient in at least
one programming language, you may wish to do your own CGI and web
server programming. If not the actual programming, you may feel
up to acquiring and installing existing programs (visit Perl
101). The source for Perl and a developer's site, www.perl.com,
is a must-visit if you're thinking about delving into
Perl programming.
|
