Using Script in Web Pages
Today's web sites need to go much beyod
HTmL. There is a definite need to allow
users, browsing through a web site,
to actually interact with the web site.
The web site must be intelligent enough
to accept users input and dynamically
structure web page content, tailor made,
to a suer's requirements.
This may be as simple as ensuring a
web page delivered to a user, having
a background color that the ser is comfortable
with or as delivering a web page with
special textual formatting for a user
with visual disabilities.
User's who browse through a web site
todfay, prefer to chose to view what
interests them. Hence even the 'content'
of a web page needs to be dynamic, based
on what a user wishes to see.
This requires a web site development
environment that will allow the creation
of 'Interactive' web pages. These web
pages will accept input from a user.
Based on the input received return customized
web pages, both in content and presentation,
to the user.
In the absence, of any user input the
web site must be intelligent enough
to return a default web page containing
predetermined information and text formatting.
This calls for a web site development
environment with coding techniques capable
of accepting a client's requests and
processing these requests. The result
of the processing being passed back
to the client via standard HTML pages.
The need to rtuen standard HTML pages,
that map to a user's input, is due to
the fact that browsers use HTTP tocommunicate
with a web server and are designed to
interpret and render HTML on a client's
machine.
Capturing user request is traditionally
done via a 'Form'. Hence the web site
developmen environment needs to have
the facilities to create forms.
After a form captures user input, the
form must have a builit in techiuq for
sending the information captured back
to the web server for processing. Processing
user request is generally done via scripts
(small programs) that are based on the
server.
The web site development environment
should also provide the facility for
'Validating' user input. Invalid user
input, will either cause data to be
sent back from the web server to the
browser, which is not what the user
wants or gaiver rise to an error message
being sent back to the browser from
the web server. Neither of which would
really attract repeat visits to the
web site.
Hence the web site development environment
must also facilitate coding which runs
in a browser at client side for data
validation. Most development environments
offer standard constructs for daa validation.
Standard programming constructs are:
Additionally, all development environemtns
provide syntax to create and use memory
variables, constants and functions.
If the development environment is object
oriented it will provide an object hierarchy
to work with. An Object Oriented Programming
(OOP) environment always offers event
driven programming. This means that
the programming environment will recognize
obect based events and allow the connection
of code snippets to these events. When
an event occurs, the code snippets will
execute.
