web111a_chapt08.ppt html: section 8 javascript cgi programs (server side programs) common gateway...

web111a_chapt08.ppt

HTML: Section 8JavaScript

CGI Programs (Server Side programs)

Common Gateway Interface

• Run on server

• Communicate with user across Internet

• Only programmer can alter the program

• Administrators can place limitations on user

• Potential overload of system

• Too many users at one time accessing programs

• Numerous languages

• Java

• Perl

• ASP

• PHP/FI

• C

• Can be complicated

8.02

web111a_chapt08.ppt

CGI Programs (Server Side Programs)

Common Uses

• Ordering Systems (shopping carts)

• Credit Card Processing

• Search Engines

• Password Protection

• Web site development by user on-line

Client Side Programs

• Are executed by the browser

• Less complicated to write and maintain

• Can be tested locally – does not have to be on the internet

• Usually more responsive to the user

• Can do a lot of checking functions

• Is an interpretative language

• Most common languages

JavaScriptVBScriptPHP/FIASP

web111a_chapt08.ppt

Active Server Pages (ASP) code

http://www.ffpc.org/ File Name: main.asp

Note: HTML code embedded with the ASP code

<h4>It is <% =weekdayname(weekday(date)) %>, <% = date %> at <% = time %> in Fenton, Michigan.

</h4>

<% If Time >= #12:00:00 AM# and Time < #12:00:00 PM# then %>

<h2>Good Morning and welcome to The ...</h2>

<% elseif time >= #12:00:00 pm# and time < #6:00:00 pm# then %>

<h2>Good Afternoon and welcome to The ...</h2><p>

<% else %>

<h2>Good Evening and welcome to The ...</h2>

<% end if %>

web111a_chapt08.ppt

JavaScript

• Simple to use

• Client side program

Script Tag

Identifies script type to browser

<script src=“url” language=“JavaScript”>

JavaScript code

</script>

url = name of external program

Language = type of script to be executed

web111a_chapt08.ppt

Page 8.07: Hiding the script from non JavaScript browsers

<script language=“JavaScript”>

<!– Hide from non-JavaScript browsers

JavaScript program

// Stop hiding from older browsers -->

</script>

JavaScript: ignored by non-JavaScript browsers

HTML: comment tag – a non-JavaScript browser will ignore all the statements between the tags

//: JavaScript comment tag:

A non-JavaScript browser will ignore

A JavaScript browser would error as the verbiage is not JavaScript commands

Note: no src attribute means the script is built into the HTML document, not coming from an external file

web111a_chapt08.ppt

LAB: Figure 8-6, Page 8.08

Files are located at F:\Assign\Fulcher\web111a\tutorial.08

-------------------------------

JavaScript

document.write(“text to the screen – no line return”);

document.writeln(“text to the screen with a line return”);

May include HTML in JavaScript


Writing a document to the screen

8.08

web111a_chapt08.ppt

Working with VariablesVariable: a named element in a program that stores

information

Store/gather information in one part of program to be used in another part

Assignment format: (.11)

variabl-ename = data-into-variable;

Example: (Page 8.11 – 8.12)

Year = 2003;

document.write(Year);

document.write(“The year is “ + Year);

8.11

web111a_chapt08.ppt

Variable TypesNumeric: numbers

One decimal position allowed

Dash (-) allowed to show negative

Can do arithmetic with this type

String: group of characters

Enclosed in quotes (“)

Letters of the alphabet

Numbers (cannot do arithmetic)

Boolean: logical one (yes) or zero (no) only

Null: has no value assigned

Declaring (creating) Variables

Var name-of-variable = value-of-variable;

Var Month; variable is nullVar Month = “December”; creates and assignsMonth = “December”; assigns a value


8.12

8.12

web111a_chapt08.ppt

Date/Time ValuesFormat

Variable = DateObject.JavaMethod();

Get current date information

Variable = new Date();

Example:

Today = new Date();

Now, each of the Date Methods can access the date information

Figures 8-9, 8-10, Page 8.17


8.16

8.16

web111a_chapt08.ppt

Expressions and OperatorsUse

Variables

Values

Operators

Perform actions within an expression

+ Increment (add)

+ Join two elements

+ to Increment

Var ThisMonth = today.getMonth()+1;

+ to Join elements

document.write(“Only “ + DaysLeft + “ days until Christmas”);

Arithmetic Operators

Figure 8-13, Page 8.20

8.19

8.19

8.20

web111a_chapt08.ppt

Expressions and OperatorsAssignment Operators

Assign one element (or result) to another element

=

Most common

element1 = element2;

+=

Uncommon

Used to concatenate string data

Assignment Operators


8.21

8.21

8.21

web111a_chapt08.ppt

Math object and Math MethodsObjects: libraries of functions

Method: a specific function in an object

Math object

A set/group of math functions built into the browser program

Math method

Specific program (function) inside the Math object to handle a specific operation


8.22

web111a_chapt08.ppt

JavaScript FunctionsSeries of commands that perform an action (program)

function function_name(parameters) {

javascript commands; }

XmasDays Function Page 8.25

LAB: Figure 8-17 and 8-18, Page 8.27

8.23

web111a_chapt08.ppt html: section 8 javascript cgi programs (server side programs) common gateway...

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