Embed Size (px)
Citation preview
Client-Side Web Application Development with JavaScript
ISYS 350
Types of Web pages
• Static page:– The contents of a web page is predefined by
HTML tags and other mark up languages.• Example: david chao’s home page.
• Dynamic page– A web page includes contents produced by a
programming language when the page is opened.
– Examples: • Pages that display current date/time, visitor counter
– Yahoo home page• Pages that display results based on a database query.
– Yahoo’s Finance/Enter symbol/Historical prices
Technologies for Creating Dynamic Pages• Client-side technology
– HTML – Browser Document Object Model (DOM) – JavaScript– Cascade Style Sheet, CSS
• Server-side technology– Microsoft .Net– PHP– Java– Others
Example of Client-side Page using HTML, DOM and JavaScript
HTML Introduction
• History:– http://en.wikipedia.org/wiki/HTML
• Standard– The World Wide Web Consortium (W3C)
• HTML 5: <!DOCTYPE html> – Multimedia controls
• Video, audio, canvas
– Controls with build-in validation
Online Resources for Learning HTML
• w3schools.com – http://www.w3schools.com/default.asp
HTML Tags (Elements)
• Heading section– <head>, <title>, <meta>, <script>, etc.
• Body section– <body>, <p>, <h1> to <h6>, <a>, <br>– Formatting: <b>, <I>, <u>, <center>– Comment: <!-- comment -->– List <ul>– Image– Table: <table>, <tr>: a new row in table, <td>: a new cell in
a table row.– Form: <form>, <input>, <select>
HTML Attributes• HTML elements can have attributes that provide
additional information about an element.• Attributes are always specified in the start tag• Attributes come in name/value pairs like:
name="value“• Name and value are case-sensitive and lowercase is
recommended.• Examples:• <form id=“tf” name="testForm">• <div id="content">• <h1 class="center">• <img src="w3schools.jpg" alt="W3Schools.com" width="104" height="142">
TABLE Tag<table id=“depTable“ border="1" width=“400"> <thead>
<tr><th>Year</th>
<th>Value at BeginYr</th><th>Dep During Yr</th>
<th>Total to EndOfYr</th> </tr> </thead> <tbody>
<tr> <td>1</td> <td>2000</td> <td>400</td> <td>400</td> </tr> </tbody></table>
FORM Tag
• Form attributes:– mame: Form’s name, id
• For server-side form:– action: Specify the URL of a program on a server or an
email address to which a form’s data will be submitted.– method:
• Get: the form’s data is appended to the URL specified by the Action attribute as a QueryString.
• Post: A preferred method for database processing. Form’s data is sent in the HTTP body.
A form may contains:
• Textbox• Check box• Listbox• Radiobutton• Button• Etc.
Adding HTML ControlsTools/Palette/HTML, JSPCode Clips
Creating HTML Form: Double-click Form element
Create a Form Using NetBean
Step by Step• 1. Add a form tag:
– Name property– Action: server-side program; leave it blank for client-side
• 2. Add lables by typing• 3. Add text input • 4. Add dropdown list:
– Number of options
• 5. Add radiobutton– All buttons belong to a group
• 6. Add button– Lable– Type:
• Submit – submit to a server• Standard – client-side
• 7. Add <br> to start a new line
Dropdown List Example
<select name="Rate"> <option value=.04>4%</option> <option value=045>4.5%</option> <option value=.05 >5%</option> <option value=.055>5.5%</option> <option value=.06>6%</option> </select>
RadioButton Example:RadioButtons having the same name
belong to one group
<input type="radio" name="Year" value=10 />10 year<<br><input type="radio" name="Year" value=15 />15 year<br><input type="radio" name="Year" value=30 />30 year<br>
<form name="fvForm" action=""> Enter PV: <input id='PV' type="text" name="PV" value="" /><br> Select Rate: <select name="Rate"> <option value=0.04>4%</option> <option value=0.045>4.5%</option> <option value=0.05>5%</option> <option value=0.055>5.5%</option> <option value=0.06>6%</option> <option value=0.065>6.5%</option> <option value=0.07>7%</option> </select><br> Select Year: <br> <input type="radio" name="Year" value=10 />10 year<br> <input type="radio" name="Year" value=15 />15 year<br> <input type="radio" name="Year" value=30 />30 year<br> <br> Future Value: <input type="text" name="FV" /> <br> <input type="button" value="ComputeFV" name="btnCompute" onClick="ComputeFV()" /> </form>
Note: We can assign an id to a HTML tag (element).
HTML Tags and Eventshttp://www.w3schools.com/tags/ref_eventattributes.asp
• Link <a> </a>: click, mouseOver, mouseOut• Image <img>: abort(loading is interrupted), error,
load.• Area <area>: mouseOver, mouseOut• Body <body>: blur, error, focus, load, unload• Frameset: blur, error, focus, load, unload• Frame: blur, focus• Form: submit, reset• Textbox, Text area: blur, focus, change, select• Button, Radio button, check box: click• List: blur, focus, change
Event Handler
• Event handler name: on + event name– Ex. onClick
• Calling a handler:– onClick="CompSumJS()“– onClick="window.alert('you click me')"
– Note: single quote/double quote
Example of Event Handler<script >function showSum(){ num1=parseFloat(window.prompt("Enter Num1: ")); num2=parseFloat(window.prompt("Enter Num2: ")); sum=num1+num2; window.alert("The sum is: " + sum.toString());}</script> </head> <body> <form name="testText">
<input type="button" value="showTest" name="btnTest" onClick="showSum()"/> </form> </body>
Browser Object Modelhttp://w3schools.com/jsref/default.asp
N a v ig a to r L o ca tion
T e xt
R a d io
C h e ckB ox , e tc
F o rm co lle c tion
Im a ge
L ink
A n ch o r, e tc
O th e r co llec tio ns
D o cum e nt H is to ry F ra m e
W in d ow
Window Object• The Window object represents a Web browser window.• Properties:
– window.status, window.defaultstatus– window.document, window.history, window.location.– Window.name
• Methods:– window.open (“url”, “name”, Options)
• Options: menubar=no, status=no, toolbar=no, etc.– window.close– window.alert(“string”)– window.prompt(“string”)– Window.focus, Etc.
• Try statements at: http://w3schools.com/jsref/default.asp
Navigator Object
• The navigator object provides information about the browser.
• Properties:– Navigator.appName:browser name– Navigator.appCodeName: browser code name– Navigator.appVersion– Navigator.platform: the operating system in use.
Location Object
• Allows you to change to a new web page from within a script code.
• To reload a page:– location.reload()
• To open a page: Assign()– Ex. location.assign(URL)
Testing<html>
<head>
<title></title>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<script>
function openNew(){
site=window.prompt("enter url:");
window.open (site);
site=window.prompt("enter url:");
location.assign(site);
}
</script>
</head>
<body>
<p><input type="button" value="Button" name="B3" onclick="openNew()"></p>
</body>
</html>
History Object
• Maintain a history list of all the documents that have been opened during current session.
• Methods:– history.back()– history.forward()– history.go(): ex. History.go(-2)
Document Object
• The document object represents the actual web page within the window.
• Properties: – background, bgColor, fgColor, title, url, lastModified,
domain, referrer, cookie, linkColor, etc. • Ex. document.bgColor=“silver”;
• Methods: – document.write (“string”)– document.open, close
Use document object to access data entered on a form
• Using the future value form as an example:– Form name: fvForm– Textbox name: PV– Dropdown list: Rate– Radiobutton group name: Year
Accessing data entered on a form• Textbox:
– document.fvForm.PV.value
• Dropdown list:– document.fvForm.Rate.options[document.fvForm.R
ate.selectedIndex].value
• Radiobuttons:if (document.fvForm.Year[0].checked) {myYear=10;}else if (document.fvForm.Year[1].checked) {myYear=15;}else {myYear=30;}
CheckBox
document.LoanForm.checkBox1.checked
Alternative way using the id attribute
document.getElementById(“PV").value
JavaScript Reference
• http://w3schools.com/js/default.asp
Client Side Script
• <script>• ……• ..statements• </script>
• Note: Typically the script is embedded in the <head> section.
JavaScript Variable Declaration
• var intrate, term, amount;• Data Type:
– Variant - a variable’s data type is determined when it is initialized to its first value.
• Variable scope:– Local: Variables declared in a function or procedure.– Global: Variables declared in the heading section, but not in
a function or procedure.
• Variable name is case-sensitive.• Note: We can use a variable without declare it.
Statements
• Statements:– End with “;”– Block of code: { }
• Comments:– Single-line comment: //comment– Block comment:
• /* comment comment */
Arrays
• var arrayName = new Array(array size);• var Pet = new Array(2);• Pet[0]=“dog”;• Pet[1]=“cat”;• Pet[2]=“bird”;
var names=new Array(); names[0]="peter"; names[1]="paul"; names[2]="mary";
Note: Optionally, it is not require to declare array size.
Operators
• Arithmetic operators:+, -, *, /Math.pow(x,y), etc.
• Math is an object with many methods such as round(x), random(), sqrt(x), ceil(x), floor(x), etc.
• Note: “pow” has a lowercase p.
• Comparison operators:= = , !=, <, >, <=, >=
• Logical operators:&&, ||, !
Formula to Expression
AB
B
A
Y
X
Math.pow(A,B) Math.pow(X/Y,A/B)
IF StatementsJS: if (condition) {
statements;}else {
statements;}
if (document.fvForm.Year[0].checked) {myYear=10;}else if (document.fvForm.Year[1].checked) {myYear=15;}else {myYear=30;}
Switch Case Statementsswitch(varable name) {case value1:
statements;break;
case value2:statements;break;
…default:
statements;break;
}
Loop Structures1. while (condition) {
statements;}
2. for (var I = 0; I<5;I=I+1){statements;
}
Note: Use Break statement to exit loop earlier.Ex. Break ;
JavaScript’s Conversion Functions• parseFloat:for conversion to a floating-point number:
– Ex. parseFloat('77.3') -> 77.3
• parseInt: for string-to-integer conversion– Ex. parseInt('123.45') -> 123
• toString(), toFixed(n) example:• Price=5;• Qty=10;• Amount=Price*Qty;• document.write (Amount.toString());• document.write (Amount.toFixed(2));
• eval• strVar = “5”;• numVar = eval(strVar)• Eval(Price*Qty)
Try Catch
try { //Run some code here } catch(err) { //Handle errors here }
window.prompt: similar to VB’s inputBoxwindow.alert: like MessageBox
function showSum(){ num1=parseFloat(window.prompt("Enter Num1: ")); num2=parseFloat(window.prompt("Enter Num2: ")); sum=num1+num2; window.alert("The sum is: " + eval(num1+num2)); window.alert("The sum is: " + sum);}
JavaScript Functions
• Defining functions– function functionName(arg1,..,argN){
• Statements;• return valueToReturn;
}
Note: 1. The arguments are optional.2. The return statement is optional. A JavaScriopt function is
not required to return a value.
Example: JavaScript to Compute the sum of two values
<script >function ComputeSum(){n1=document.testForm.num1.value;n2=document.testForm.num2.value;document.testForm.valueSum.value=eval(n1)+eval(n2);}</script>
JavaScript to compute the future value
<form name="fvForm" action=""> Enter PV: <input id='PV' type="text" name="PV" value="" /><br> Select Rate: <select name="Rate"> <option value=0.04>4%</option> <option value=0.045>4.5%</option> <option value=0.05>5%</option> <option value=0.055>5.5%</option> <option value=0.06>6%</option> <option value=0.065>6.5%</option> <option value=0.07>7%</option> </select><br> Select Year: <br> <input type="radio" name="Year" value=10 />10 year<br> <input type="radio" name="Year" value=15 />15 year<br> <input type="radio" name="Year" value=30 />30 year<br> <br> Future Value: <input type="text" name="FV" /> <br> <input type="button" value="ComputeFV" name="btnCompute" onClick="ComputeFV()" /> </form>
Note: We can assign an id to a HTML tag (element).
<script>function ComputeFV(){//myPV=eval(document.fvForm.PV.value);myPV=parseFloat(document.fvForm.PV.value);//myRate=eval(document.fvForm.Rate.options[document.fvForm.Rate.selectedIndex].value);myRate=parseFloat(document.fvForm.Rate.options[document.fvForm.Rate.selectedIndex].value);if (document.fvForm.Year[0].checked) {myYear=10;}else if (document.fvForm.Year[1].checked) {myYear=15;}else {myYear=30;}fv=myPV*Math.pow(1+myRate,myYear);document.fvForm.FV.value=fv.toString();}</script>
Code Example
Using document.getElementById<form name="fvForm"> Enter PV: <input type="text" id ="PV" name="PV" value="" size="10" /><br> <select name="Rate" id="Rate"> <option value=".04">4%</option> <option value=".05">5%</option> <option value=".06">6%</option> <option value=".07">7%</option> <option value=".08">8%</option> </select><br> Select Year: <br> <input type="radio" name="Year" value=10 id="Year10" />10 year<br> <input type="radio" name="Year" value=15 id="Year15" />15 year<br> <input type="radio" name="Year" value=30 id="Year30" />30 year<br> <br> Future Value: <input type="text" name="FV" id="FV" /> <br> <input type="button" value="ComputeFV" name="btnCompute" onClick="ComputeFV()" /> </form>
<script>
function ComputeFV(){//myPV=eval(document.fvForm.PV.value);myPV=parseFloat(document.getElementById("PV").value);myRate=parseFloat(document.getElementById("Rate").value);if (document.getElementById("Year10").checked) {myYear=10;}else if (document.getElementById("Year15").checked) {myYear=15;}else {myYear=30;}fv=myPV*Math.pow(1+myRate,myYear);document.getElementById("FV").value=fv.toString();//document.fvForm.FV.value=fv.toString();}</script>
Years to Reach Goal
Form Code
<form name="testForm"> PV: <input type="text" name="PV" value="" /><br><br> Rate: <input type="text" name="Rate" value="" /><br><br> Goal: <input type="text" name="Goal" value="" /><br><br> Year: <input type="text" name="Year" value="" /><br><br> <input type="button" value="Compute Year" name="btnCompute" onclick="ComputeYear()" /> </form>
Code Example<script>function ComputeYear(){pv=eval(document.testForm.PV.value);rate=eval(document.testForm.Rate.value);goal=eval(document.testForm.Goal.value);for (i=0; true; ++i){ fv=pv*Math.pow(1+rate,i); if(fv>=goal){ document.testForm.Year.value=i; break; } }}</script>
Using while loop
year=0;while (fv<goal) { year=year+1; fv=pv*Math.pow(1+rate,year); if(fv>=goal)
{ document.testForm.Year.value=year; break; } }
Working with TableStraight Line Depreciation Table
HTML Table Tag
• <Table> : id and name attributes– <thead>: Table Heading section
• <tr>: new row– <th>: column heading
– <tbody>: data rows
HTML Form Code<body> Straight Line Depreciation Table <form name="depForm"> Enter Property Value: <input type="text" name="pValue" value="" /><br> Enter Property Life: <input type="text" name="pLife" value="" /><br> <input type="button" value="Show Table" name="btnShowTable" onclick="showTable()" /> </form> <table id="depTable" border="1" width="400" cellspacing="1"> <thead> <tr> <th>Year</th> <th>Value at BeginYr</th> <th>Dep During Yr</th> <th>Total to EndOfYr</th> </tr> </thead> <tbody> </tbody> </table> </body>
Table/Row/Cell Object• Table object:
– Properties:• rows: collection of data rows (including the header row)
– rows.length: number of rows– 0-based index
– Methods:• InsertRow(index)• deleteRow(index)
• Data Row object method:– insertCell(index)
• Cell object:– innerHTML property: cell’s data
HTML element’s innerHTML property
• Each HTML element has an innerHTML property that defines both the HTML code and the text that occurs between that element's opening and closing tag. By changing an element's innerHTML after some user interaction, you can make much more interactive pages.
• Assigning a value:– document.getElementById(“p”).innerHTML = 5;
function showTable(){value=eval(document.depForm.pValue.value);life=eval(document.depForm.pLife.value);depreciation = value / life;var table = document.getElementById('depTable'); var totalDepreciation=0;
for(var i = table.rows.length - 1; i > 0; i--){ table.deleteRow(i);}for (count = 1; count <= life; count++) { var rowCount = table.rows.length; var row = table.insertRow(rowCount); var cell0 = row.insertCell(0); cell0.innerHTML=count; var cell1 = row.insertCell(1); cell1.innerHTML="$" + value.toFixed(2); var cell2 = row.insertCell(2); cell2.innerHTML="$" + depreciation.toFixed(2); totalDepreciation += depreciation; var cell3 = row.insertCell(3); cell3.innerHTML="$" + totalDepreciation.toFixed(2); value -= depreciation;} }
Validating Data: The property value and life boxes cannot be blank
<script >function Validating(){var Valid;Valid=true;if (document.depForm.pValue.value=="" ||document.depForm.pLife.value=="") {Valid=false;}
if (Valid==false) {alert("Property value or life cannot contain blank");}else {showTable();}}</script>
Note: the button’s onClick event will call the Validating function:<input type="button" value="Show Table" name="btnShowTable" onclick="Validating()" />
Useful function for Validation
• isNaN(): The isNaN() function determines whether a value is an illegal number (Not-a-Number). This function returns true if the value is NaN, and false if not.
isNaN examplefunction Validating(){var Valid, Valid2;Valid=true;Valid2=true;
if (document.depForm.pValue.value=="" ||document.depForm.pLife.value=="") {Valid=false;}if (isNaN(document.depForm.pValue.value) ||isNaN(document.depForm.pLife.value)) {Valid2=false;} if (Valid==false) {alert("Property value or life cannot contain blank");}if (Valid2==false) {alert("Enter digits only");} if (Valid && Valid2) { showTable(); }}
