Scripting Language Presentation-ELCL700

Transcript Scripting Language Presentation-ELCL700

Server-Side
vs. Client-Side
Scripting Languages
What are they and what are their differences?
By Lories Slockbower
S
What is
server-side
scripting?
Server-side scripting is a method
of programming for the web that
runs software on the server rather
than the browser or installed
plugins to create dynamic web
pages.
Languages used for these tasks
are normal programming
languages which include Perl,
PHP, JSP, Ruby, ColdFusion, and
Python
What can server scripts do?
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Customize a web page and
dynamically change its contents
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Respond to queries from users or
from HTML forms
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Access database and send the
information back to the browser
Advantages of
server-side
scripting
User does not need to download plugins like
Java or Flash
User can create one template for the entire
website
The site can use a content management
system which makes editing simpler.
Generally quicker to load than client-side
scripting
User is able to include external files to save
coding
Scripts are hidden from view so it’s more
secure. Users only see the HTML output.
Disadvantages of server-side
scripting
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The scripts can be used by
attackers to access the server. They
do this by changing the URL to
something that takes advantage of
a hole in security. System
administrators must keep all serverside scripting updated and use an
application firewall to prevent this.
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Scripting software must be installed
on the content management system
tools in order to store the dynamic
data.
Common server-side scripting
languages
S ASP/ASP.net –Active Server Pages developed by Microsoft to
make advanced web pages. Unix servers use Chillisoft ASP.
Allows user to get any .net-enabled language to program a site.
S JSP/Servlets – Java Server Pages which include JSP tags mixed in
with html. Most popular language for higher level applications.
S ColdFusion – Runs on top of a JSP/servlet engine. Can cost
$1,299 a server. Users can download a free “developer” edition
but that is limited to one IP address.
Server-side scripting example
ASP source:
<html>
<body>
<%
response.write("Hello World!")%>
</body>
</html>
Output result
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Hello world!
More server-side scripting
languages
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Perl – Practical Extraction and Reporting
Language, first released in 1987, is a
powerful language with advanced features.
Available for free from various scripting
directories. Supported by operating
systems UNIX, MAC OS 7-9 and
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PHP or PHP Hypertext Preprocessor is
an open source language. Considered by
“standard’ choice for server side scripting
in Unix/Linux platforms.
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Python- Created in 1989, it is not
supported by most web hosting companies.
Although easy to learn, there is no
standard web application framework for it.
What is client-side scripting
language?
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Client-side scripts are placed within an
HTML document in the user’s web
browser rather than the web server to
allow greater interactivity in a
document. For example – client-side
scripting could check the user’s form for
errors before submitting it
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Enables web pages to change content
according to user input and other
variables, including the time of day.
Can also be stored in a separate file that
is referenced to the documents that use
it.
How does it work?
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Usually, JavaScript code starts with
the tag <script
language="JavaScript"> and ends
with the tag </script>.
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Files are first sent to the user’s
computer by the web server which
executes the script and displays the
document.
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The client-side script may also
include browser directions based
on certain user functions such as
clicking buttons.
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Frequently, you can see the the
source card by viewing the file that
contains the script.
Example of client-side scripting
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Suppose a person completes a
form but omits information.
When they slick the submit
button, an alert box appears
telling them about the mistake.
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This is JavaScript and is an
example of Client Side Scripting
because all the activity takes
place inside the browser.>
Advantages of client-side
scripting
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Allows for more interactivity
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Can perform actions quickly
without going to the server
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May be easier to use for those
whose browsers don’t support
scripts
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Are available from many free
resources such as Hotscripts.com
and Javascript.com
Disadvantages of client-side
scripts
S If the user’s browser is out of date, the website will not display
properly.
S More quality assurance testing is required because different
browsers support scripts differently
S Not secure because anyone can look at the code in the page source
S Some browsers will disable the active content and tell the user
they may be harmful.
Client-side scripting language
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JavaScript – Not to be confused
with Java, JavaScript client-side
is a programming language is
implemented as part of the web
browser to enhance dynamic
websites
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VBScript is a programming
language that can manipulate the
document objects and the
browser
So how to know which to use?
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Know your audience – Be sure to know
what scripts work best with the browsers
your audience will use. JavaScript is most
compatible with Microsoft Internet
Explorer and Netscape. VBScript usually
just works on Internet Explorer.
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Test scripts on the browsers for both PC
and MAC users as browsers on the MACs
don’t support scripts as well as the PC
versions do.
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Scripts should be tested on at least the
previous two versions of your audience’s
browser since people are slow to update
their browsers so the latest scripts may not
work.
References
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http://www.w3schools.com/web/web_scripting.asp
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http://www.serverschool.com
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http://en.wikipedia.org/wiki/JavaScript
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http://opensourcetutorials.com/Design-AndLayout/Usability/web-widgets
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http://htmlhelp.com/reference/html40/special/script.html
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http://astahost.com/info.php/serverside-clientside_t16081.html
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http://exforsys.com/tutorials/client-server/server-sidescripting.html
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http://www.ehow.co.uk/how_8426161_remove-client-sidescripting.html
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http://www.webdesignerdepot.com/2009/11/coding-a-webdesign-for-speed-and-quality/
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http://www.google.com/imgres?imgurl=http://nas.uhcl.edu/y
ang/research/webdevelopmentcourse/clientSideScripting.gif&
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http://rentacomputertoday.com/tag/computer-hackers/
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http://www.w3schools.com/asp/showasp.asp?filename=demo
_text
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http://whatismyipaddress.ricmedia.com/help/JavaScript/about
/

Scripting Language Presentation-ELCL700

Transcript Scripting Language Presentation-ELCL700

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