Ppt on event handling in javascript alert

Introduction to JavaScript INE2720 Web Application Software Development Essential Materials.

JavaScript Functions and Events JavaScript Functions and EventsEvents Handlers Using Object in JavaScript Using Object in JavaScript –Object-Oriented Programming –JavaScript Object Model –Using Built-In objects (Predefined Object) –Custom Object Types Error in JavaScript Error in JavaScript Exception Handling in JavaScript Exception Handling in JavaScript/ can simply click “ OK ” to close it. alert(“An alert triggered by JavaScript”); INE2720 – Web Application Software Development All copyrights reserved /


1 JavaScript csc667/867 Spring 2006 Ilmi Yoon. 2 Outline Basics of JavaScript, History Basics of the language variables, types, arrays, objects, and functions.

Form Validation Create function to run on form’s onSubmit event 45 Form Validation (continued) function checkForm(theForm){ if(theForm["firstName"].value == ""){ alert("You must enter your first name"); theForm["firstName"].focus/.write(“ ”); } 55 Another Example 56 JavaScript has Event Handlers Handling Events Example Handling Events in JavaScript 57 Example 3 58 Determining the Browser navigator is a built-in object with properties that describe the browser –defined in both IE and NS –navigator.appName is /


JavaScript 2 JavaScript 2 Timers, Images, Sniffing and Validation Dr Kevin McManus

outputs a message in an alert box and returns false otherwise it returns true. JavaScript 2 © November 11University of Greenwich45 User Confirmation If the form passes the submission validation the onSubmit event handler will be / ( valid ) return true; else return false; } test for an empty field feedback() used to handle messages to the user test for a valid string JavaScript 2 © November 11University of Greenwich51 loginForm.js // test for a valid password entry function validatePassword(passwordString) /


JavaScript CS 268. Topics Introduction to JavaScript Positioning a script Variables Type conversions Concatenation HTML forms Document Object Model Functions.

) == true) { alert("Please enter a number for your age"); return false; } return true; } function validateUserEntries() { if(validateAge(document.employee.age.value) == false) { return false; } // additional code checking other entries } Whatever the user has entered in the text input is sent to validateAge as a parameter Event Handlers Event handler: function that executes as a result of a user action  You can use a JavaScript function/


12-Aug-15 JavaScript Language Fundamentals. 2 About JavaScript JavaScript is not Java, or even related to Java The original name for JavaScript was “LiveScript”

JavaScript JavaScript has some features that resemble features in Java: JavaScript has Objects and primitive data types JavaScript has qualified names; for example, document.write("Hello World"); JavaScript has Events and event handlers Exception handling in JavaScript is almost the same as in Java JavaScript has some features unlike anything in/document is loaded in the web browser, a number of objects are created. Most commonly used are window and document Window open(), close(), alert(), confirm(), prompt/


Client-Side Programming JavaScript Dr. Ahmed Youssef.

… part 68 69 70 JavaScript Event Handling The event handler attribute consists of 3 parts: The identifier of the event handler The equal sign A string consisting of JavaScript statements enclosed in double or single quotes 71 onMouseOver=“checkForm( )” JavaScript that goes between the, tags: JavaScript included as an attribute of the “Send eMail” button: function checkForm() { if ( document.sendEmail.sender.value.length < 1) { window.alert( “Empty From field! Please/


JQuery 10/21. Today jQuery Some cool tools around the web JavaScript Libraries Drawing libraries HTML Frameworks Conventions.

cool tools around the web JavaScript Libraries Drawing libraries HTML Frameworks Conventions JavaScript in the Real World You need to make sure your code works on all browsers. Some very popular browsers don’t implement basic things according to a standard. Therefore, you often need to have special cases for basic things like event handling. Why People Use Libraries… People use JavaScript libraries to avoid needing/


Chapter 5 © 2003 by Addison-Wesley, Inc. 1 Chapter 5 JavaScript and HTML Documents.

good use of JavaScript, because it finds errors in form input before it is sent to the server for processing - Things that must be done: 1. Detect the error and produce an alert message 2. Put the element in focus (the focus function) 3. Select the element (the select function) Chapter 5 © 2003 by Addison-Wesley, Inc. 12 5.4 Events and Event Handling (continued) - The focus/


What is Java Script? An extension to HTML. An extension to HTML. Allows authors to incorporate some functionality in their web pages. (without using CGI.

JavaScript, but in general, semicolons are optional! However, semicolons are required if you want to put more than one statement on a single line. JavaScript uses them to separate commands and declarations JavaScript uses them to separate commands and declarations Some features Conditional statements Conditional statements Conditional operators Conditional operators Buttons, Alerts and Confirmation Box Buttons, Alerts and Confirmation Box Event Handling Event Handling Loops Loops Variables JavaScript/


Session: 19. © Aptech Ltd. 2HTML5 Geolocation and APIs / Session 19  Explain geolocation and its use in HTML5  Explain the Google Maps API  Explain.

of the PositionError object.  The Code Snippet demonstrates the error handling routine for the geolocation code. Handling Error © Aptech Ltd. 18HTML5 Geolocation and APIs / Session 19 function getLocation() { function showPosition(position) { alert(‘Latitude: ‘ + position.coords.latitude + ‘ ’ + ‘Longitude/.  The object of type Map is created in JavaScript, before it can be referenced in an HTML document.  The drag-and-drop operations defines an event-based mechanism using which elements on a Web page/


JavaScript Chapter 4. Topic to be covered.. What is JavaScript? What is JavaScript? Simple Program: Displaying a Line of Text in a Web Page Simple Program:

&& exp 2 outcome is true if the outcome for both exp1 and exp2 are true course == cs170 and semester <8 in JavaScript course == cs170 && semester <8 Logical OR operator || exp1 || exp 2 outcome is true if the outcome for either/of the event attribute contains the JavaScript code Example: Display an alert box when the mouse is placed over a hyperlink. 82 Home 83 Introduction  JavaScript events allow scripts to respond to user interactions and modify the page accordingly  Events and event handling help make /


Programming for WWW (ICE 1338) Lecture #5 Lecture #5 July 7, 2004 In-Young Ko iko.AT. icu.ac.kr Information and Communications University (ICU) iko.AT.

Object Model HTML Data types Data types Operators Operators Pattern matching Pattern matching Event handling Event handling July 7, 2004 6 Programming for WWW (Lecture#5) In-Young Ko, Information Communications University General Syntax of JavaScript Direct embedding of a JavaScript code: Direct embedding of a JavaScript code: -- JavaScript script – -- JavaScript script – Indirect JavaScript specification: Indirect JavaScript specification: Identifier form: begin with a letter or underscore, followed by any/


1 CSC160 Chapter 7: Events and Event Handlers. 2 Outline Event and event handlers onClick event handler onMouseOver event handler onMouseOut event handler.

a semicolon. This enables you to add additional JavaScript code after the alert, which enables you to perform multiple actions on the click event rather than just a single JavaScript statement. 10 onClick Event Handler (cont’d) In the following example, multiple actions are performed on the click event rather than just a single JavaScript statement. onclick1.htm 11 onClick Event Handler (cont’d) If the code for an/


5.1 JavaScript Execution Environment

elements 5.3 Element Access in JavaScript (continued) 3. getElementById Method (defined in DOM 1) - Example: document.getElementById("pushMe") - Checkboxes and radio button have an implicit array, which has their name ... value = "tomatoes" /> var numChecked = 0; var dom = document.getElementById("topGroup"); for index = 0; index < dom.toppings.length; index++) if (dom.toppings[index].checked] numChecked++; 5.4 Events and Event Handling - An event is a notification that/


Handling Events II 27th April 2011. Introduction Event Model Events Event Handling Navigation Events On-the-Fly Web Pages Web-Page Context Nesting On-the-Fly.

separate events Appropriate event handling grabs attention of the surfer because it makes the page dynamic Navigation Elements click event of Navigation Elements: Code click event of Divisible By Number //define event handler function sale() { str = "We have a 30% off sale today on these items" + " "; str += "All shirts and shorts in store" + " "; str += "Garden supplies" + " "; str += "Swimming pool supplies" + " "; str += "Outdoor camping equipment" + " "; str += "Beach supplies" + " "; alert/


Advanced Javascript Dick Steflik Binghamton University.

to a user provided event handling function Each object has particular events that they will respond to the way you specify an event handler is by adding an additional attribute to the HTML tag that specifies the event and the particular handler –if the button is click the function abc( ) will be run Alert The “Alert” function is useful in user notification and debugging of Javascripts. Pops up a/


WTP Unit 4 JavaScript and DHTML. Javascript: – Client side scripting, – What is Javascript, – How to develop Javascript, – Simple Javascript, – Variables,

to float eval – convert string to numbers Dialog Boxes alert() used to display message. prompt() allows user enter something. confirm() used to get user confirmation. 1 ALERT DIALOG BOX – The Alert dialog box is used to display some textual information on the/Jump to another place on the page GTU Questions What do you mean by event in JavaScript? Give at least two examples of events with their handling. (GTU-2011 May)07 Write a JavaScript program to print first N odd numbers divisible by 07 (GTU-2011 May)/


COMP 519: Web Programming Autumn 2014 Event-driven programs and HTML form elements  event-driven programs  onload, onunload  HTML forms & attributes.

Hello() { globalName=prompt("Welcome to my page. " + "What is your name?",""); } function Goodbye() { alert("So long, " + globalName + " come back real soon."); } Whatever text appears in the page. view page HTML forms most event-handling in JavaScript is associated with form elements an HTML form is a collection of elements for handling input, output, and events in a page … form elements might include: for input: button, selection list, radio button/


CSC4370/6370: Web Programming Event-driven programs and HTML form elements  event-driven programs  onload, onunload  HTML forms & attributes  button,

Hello() { globalName=prompt("Welcome to my page. " + "What is your name?",""); } function Goodbye() { alert("So long, " + globalName + " come back real soon."); } Whatever text appears in the page. view page HTML forms most event-handling in JavaScript is associated with form elements an HTML form is a collection of elements for handling input, output, and events in a page … form elements might include: for input: button, selection list, radio button/


JavaScript Specialist. Lesson 1: Introduction to JavaScript.

precedence Implement inline scripting Implement simple event handlers, including onload() and onunload() Define keywords and reserved words Using JavaScript to Communicate with the User Giving the user a message: The alert() method Using semicolons in JavaScript Getting data from the user: The/ single object The image Object The image object –Allows you to manipulate images in browsers Handling image object events JavaScript and image maps The history Object The history object –Allows the user to /


Event Handlers CS101 Introduction to Computing. Learning Goals Learn about event handlers Determine how events are useful in JavaScript Discover where.

Introduction to Computing Learning Goals Learn about event handlers Determine how events are useful in JavaScript Discover where events can be handled on a page Find out what the events are in JavaScript Determine the event handlers that are used for each event Be able to code scripts that make use of event handlers What is an Event? Something that happens when the User of the page performs some sort of action Possible/


Chapter 5 JavaScript and HTML Documents. © 2006 Pearson Addison-Wesley. All rights reserved. 5-2 5.1 JavaScript Execution Environment - The JavaScript.

Access in JavaScript (continued) 3. getElementById Method (defined in DOM 1) - Example: document.getElementById("pushMe") - Checkboxes and radio button have an implicit array, which has their name ... ... var numChecked = 0; var dom = document.getElementById("topGroup"); for index = 0; index < dom.toppings.length; index++) if (dom.toppings[index].checked] numChecked++; © 2006 Pearson Addison-Wesley. All rights reserved. 5-6 5.4 Events and Event Handling - An event is/


1 Website Development HTML Forms and JavaScript Event-driven programs and HTML form elements  event-driven programs  ONLOAD, ONUNLOAD  HTML forms &

Hello() { globalName=prompt("Welcome to my page. " + "What is your name?",""); } function Goodbye() { alert("So long, " + globalName + " come back real soon."); } Whatever text appears in the page. 3 HTML forms most event-handling in JavaScript is associated with form elements an HTML form is a collection of elements for handling input, output, and events in a page … form elements include: for input: button, selection list, radio button, check box/


1 JavaScript csc667/867 Spring 2005 Ilmi Yoon. 2 Outline Basics of JavaScript, Some simple examples Basics of the language variables, types, arrays, objects,

document.write(“ ”); } 8 Another Example 9 JavaScript has Event Handlers Handling Events Example Handling Events in JavaScript 10 Example 3 11 What JavaScript Programs Can Do Write programs to perform any computation; it is equivalent in power to a general purpose programming language Control/are not evaluated 19 Date: Browser Output 20 Using alert(), confirm(), and prompt() Example of alert, confirm, prompt function alertUser() { alert("An alert box contains an exclamation mark");} function confirmUser() { /


Chapter 5 © 2005 by Addison Wesley Longman, Inc. 1 5.1 JavaScript Execution Environment - The JavaScript Window object represents the window in which the.

with the values "text" and "address" Chapter 5 © 2005 by Addison Wesley Longman, Inc. 4 5.3 Element Access in JavaScript - There are several ways to do it - Example (a document with just one form and one widget): 1. DOM /Chapter 5 © 2005 by Addison Wesley Longman, Inc. 8 5.4 Events and Event Handling (continued) - Event handlers can be registered in two ways: 1. By assigning the event handler script to an event tag attribute onclick = "alert(Mouse click!);" onclick = "myHandler();" 1 Chapter 5 © 2005 by/


Chapter 5 © 2014 by Pearson Education 1 5.1 JavaScript Execution Environment - The JavaScript Window object represents the window in which the browser.

JavaScript, because it finds errors in form input before it is sent to the server for processing - So, it saves both: 1. Server time, and 2. Internet time - Things that must be done: 1. Detect the error and produce an alert message 2. Inform the user of the error and present the correct format Chapter 5 © 2014 by Pearson Education 12 5.7 Handling Events/


Client-Side programming with JavaScript 2. Event-driven programs and HTML form elements event-driven programs  onload, onunload  HTML forms & attributes.

Hello() { globalName=prompt("Welcome to my page. " +"What is your name?",""); } function Goodbye() { alert(“Goodbye, " + globalName + " come back real soon."); } Whatever text appears in the page. view page HTML forms most event-handling in JavaScript is associated with form elements an HTML form is a collection of elements for handling input, output, and events in a page … form elements might include: for input: button, selection list, radio button, check/


Chapter 5 © 2010 by Addison Wesley Longman, Inc. 1 5.1 JavaScript Execution Environment - The JavaScript Window object represents the window in which the.

Access in JavaScript (continued) 3. getElementById Method (defined in DOM 1) - Example: document.getElementById("pushMe") - Checkboxes and radio button have an implicit array, which has their name ... ... var numChecked = 0; var dom = document.getElementById("topGroup"); for index = 0; index < dom.toppings.length; index++) if (dom.toppings[index].checked] numChecked++; Chapter 5 © 2010 by Addison Wesley Longman, Inc. 9 5.4 Events and Event Handling - An event is/


Click to edit Master subtitle style Java Developer Conference 2010 Hazem Saleh Ed Burns Mashups in the JavaServer Faces World.

event … function marker1DragHandler(latlng) { alert("Current marker1 latlng is: " + latlng); } … … function marker1DragHandler(latlng) { alert("Current marker1 latlng is: " + latlng); } … GMaps4JSF and JavaScript Click to edit Master subtitle style GMaps4JSF and JavaScript  GMaps4JSF does not lock the door in the face of JavaScript customization.  GMaps4JSF components can be accessed from the JavaScript/ } } catch (Exception e) { // Exception Handling } Searching Example Click to edit Master subtitle style/


Introduction to JavaScript Pat Morin COMP Outline What is JavaScript? – History – Uses Adding JavaScript to HTML JavaScript syntax JavaScript events.

complete list of event types is available here – http://www.w3schools.com/jsref/jsref_events.asp 17 Exception Handling JavaScript also has try, catch, and throw keywords for handling JavaScript errors try { runSomeCode(); } catch(err) { var txt="There was an error on this page. " + "Error description: " + err.description + " " alert(txt) } 18 Comments in JavaScript Comments in JavaScript are delimited with // and /* */ as in Java and C++ 19 JavaScript Objects JavaScript is object-oriented and/


AJAX: Asynchronous JavaScript And XML

JavaScript functions We obviously need the function for creating a new XMLHttpRequest object, which we will store in a global variable called “ajaxRequest”. The search will be handled by setting up a Timeout event, based on entering text in/ { if (ajaxRequest.status == 200) // check to see if successful { displaySearchResults(); } alert("Request failed: " + ajaxRequest.statusText); The JavaScript functions (cont.) function displaySearchResults() // This function will display the search results, and is the/


1 A World Wind Tour of JavaScript JavaScript. 2 Objectives l Introduction to JavaScript »JavaScript: Its Beginnings –Advantages and disadvantages –How.

left a window item (then can specify some action) 36 Example of a JavaScript Event my form function genAlert() { alert( "Dont do that!" ); } When click form item then do genalert() code. 37 Debugging JavaScript l Both Netscatpe and Firefox have built in JavaScript debug tool From URL line type javascript: Entering javascript: will open a JavaScript debug window Any error messages, while script runs will show errors here Common/


1 Week 10 A World Wind Tour of JavaScript JavaScript.

alert 18 Dealing with Browsers that don’t Support JavaScript You may have noticed something a little strange about the examples so far. This makes the script invisible to browsers that don’t support JavaScript by “commenting it out”. In addition, you can provide some page content that only displays when the browser DOESN’T handle JavaScript: Your browser doesn’t support Javascript/ when the submit button is clicked, we define the onsubmit event for the form: onsubmit=“return checkitout();” a value of false/


20-Jun-15 JavaScript and HTML Simple Event Handling.

enclosed in a form method tells how to send the form data; action tells where to send it The tag is input with attribute type="button" The name can be used by other JavaScript code The value is what appears on the button onclick is the name of the event being handled The value of the onclick element is the JavaScript code to execute alert pops/


JavaScript 1 JavaScript 1 Introduction and DOM Dr Kevin McManus

document after it has loaded we will look at that soon See what happens if document.write() is used in an event handler JavaScript 1 © 2014the University of Greenwich 30 Confirmation onclick="return confirm(Really take the link?)" confirm() is similar to alert() and prompt() in that it generates a message box. It returns a Boolean to indicate if the user selected “OK” or “cancel/


(CS1301) Introduction to Computer Programming City Univ of HK / Dept of CS / Helena Wong 1. Overview of Programming and JavaScript - 1

ways to include JavaScript in HTML code: Welcome! Demo Function : Functions are executable code that you can call to perform some kind of operation. Quotes : … and "…" are interchangeable: "alert( Welcome );" is the same as alert(" Welcome "); But, of course, it is wrong to write "… or …" (unmatched single / double quotes) That means, whenever the onclick event happens, the browser handles it by calling JavaScripts alert function to show "Welcome/


CHAPTER 10 JAVASCRIPT. LEARNING OBJECTIVES Using JavaScript, web developers perform client-side processing that may include CSS field modification, form.

functions. To handle events, such as user mouse or keyboard operations, users can specify a JavaScript function the browser will call when the event occurs. Before a web page submits a form’s data to a remote script, the page should use JavaScript to validate that the user has provided a value for the form’s required fields. SIMPLE JAVASCRIPT--HELLO alert(Hello, JavaScript!); JAVASCRIPT OLD SYNTAX In the previous/


JQuery. What is jQuery? jQuery is a fast, small, and feature-rich JavaScript library that simplifies HTML document traversing and manipulation event handling.

JavaScript library that simplifies HTML document traversing and manipulation event handling animation Ajax interactions for rapid web development http://jquery.com jQuery: the most popular JS library http://w3techs.com/technologies/history_overview/javascript_library/all jQuery: the most popular JS library http://w3techs.com/technologies/history_overview/javascript_library/all History First released in/html, function(data) { $(.result).html(data); alert(Load was performed.); }); Doing Ajax with jQuery Rating/


1 Week 3 – User Input Validation with JavaScript Client-side user input validation Selected features of the JavaScript language Use of JavaScript for form.

alert/JavaScript Scripting language designed for use in client-side programming in web pages In/in/JavaScript object associated with the event (which is the form in/ JavaScript uses /Event/zip)) { alert(“please enter a/val)) { alert(“please enter a 5 / CWB40 Regular Expression Patterns in JavaScript /hello/  matches “/enclosed in parentheses/342, 343 in Anderson-Freed./in JavaScript/alert(“Please enter a 5 or 9 digit zip code”); } COMP/DCOM 461 – CWB45 Using Patterns in JavaScript/-1 ) { alert("Please enter a /In/


© Keith Vander Linden, 2005 1 Need to modify the ASP.Net slides to more coherently cover the ASP material in the text, chapters 6 & 8. Cover reasons to.

JavaScript (cont.) © Keith Vander Linden, 2005 30 function validEntries() { …function code here… return true; } …HTML header/body here… Script Functions © Keith Vander Linden, 2005 31 function validEntries() { // Alert the user when they don’t name the plan. if (document.frmAttackPlanner.txtName.value == ""){ alert/ByVal e As System.Web.UI.WebControls.DataGridCommandEventArgs) _ Handles DataGrid1.EditCommand Edit the datagrid row in the click events item index. DataGrid1.EditItemIndex = e.Item.ItemIndex /


© Minder Chen, 1998-2002 JavaScript Example - 1 Learning JavaScript By Examples by Minder Chen

() –Event Handling Procedures: OnClick="…." 3 X: X=Y S1S2 True False TempConvert(32, X) TempConvert(F, C) F C © Minder Chen, 1998-2002 JavaScript Example - 4 hello_world.htm Hello World! document is an object. Write( ) is a method associated with document. It allows you to write text to an HTML document that is currently displayed in a browser. © Minder Chen, 1998-2002 JavaScript Example - 5 alert/


Lecture 7: Basic Javascript..  Javascript programming:  Why is Javascript necessary?  Variables.  Reading and manipulating page values.  Getting.

something a fixed number of times.  Two loop statements in Javascript: while and for:  var x = 0; while (x < 5) { alert(x);//Will pop up “0”, “1”, “2”,/in Javascript called “null”.  You can check for “null” in an “if” and handle this case appropriately. ▪ if (a == null) { //do something }  What do we do with this reference? Store it in/ can then be used in subsequent alterations.  var oldhref = link.href;  HTML elements have several events, which are Javascript functions triggered when certain things/


Introducing JavaScript. Javascript code is triggered by “events” Document Eventsonload, onunload Mouse Eventsonclick, ondblclick onmousedown, onmouseup.

; //also gobal function display(msg) //This msg is local { var local; alert(msg+local+counter); counter++; } display("Local value of msg"); display(msg); //Use/ return a value void is often used to signify that an event doesn’t propagate []. [] and. are called the member of operators. In JavaScript they do the same thing myList[‘Sam’]= {midterm: 68, /window’s size Window.navigatorInformation about the browser Window.consoleGives one a handle on the console object Window.locationThe current URL (can be reset)/


Multimedia Data Introduction to JavaScript and Scaleable Vector Graphics (SVG) Dr Sandra I. Woolley

to events with event handlers.  In JavaScript, if the user clicks on a button the onClick event handler will take note of the action and perform the specified task.  When we write scripts we do not need to anticipate every possible event the user might take, we just encode the ones we want. E.g., pages load as normal without an onLoad event handler. EventWhat it handles onAbortUser/


Client side scripting - javascript Pertemuan 4 Matakuliah: Web Programming Tahun: 2009.

function Hello() { globalName=prompt("Welcome to my page. " + "What is your name?",""); } function Goodbye() { alert("So long, " + globalName + " come back real soon."); } Whatever text appears in the page. HTML forms most event-handling in JavaScript is associated with form elements an HTML form is a collection of elements for handling input, output, and events in a page … form elements might include: for input: button, selection list, radio button, check/


JavaScript, by Dr. Khalil1 JavaScript Dr. Awad Khalil Computer Science Department AUC.

document.writeln( " Rating " + " Frequency " ); for ( var rating = 1; rating < frequency.length; ++rating ) document.writeln( " " + rating + " " + frequency[rating] + " " ); document.writeln( " " ); } JavaScript, by Dr. Khalil68 JavaScript, by Dr. Khalil69 Event Handling  One of the more powerful anf often used techniques concerning JavaScript is events. Using event attributes in XHTML tags, such as onmouseover and onclick, you can create interactive documents that respond to user’s actions. EventTrigger/


Events DOM Event Model. HTML Events "on" + event name attribute value is javascript javascript runs 1st return false to STOP browser event (if any)

events can exist in DOM (some events only exist in DOM) function hi(){ alert("hello!"); } document.body.addEventListener( load, hi ); // after page is loads // an alert window says "hello!" removeEventListener() dispatchEvent() fake events; trigger made up events requires Event/will live until all of them are gone javascript event handling HEAVILY uses "binding" function attach_an_event(){ var myInformation= "hello"; var your_f= function(e){ alert(myInformation); } tagObject.addEventListener(click, your_f); /


Module 13 Cool (!?) Stuff (JavaScript, AJAX, Greasemonkey)

.comment –Insert nodes x.comment += blabla Events GUI reacts on events (from user + server) JavaScript is event-based language! –basis for everything: AJAX, drag&drop,... JavaScript events standardized in DOM Level 3 –events are associated to DOM nodes –unfortunately, no browser implements standard Two sides of the coin –specify: which kind of event on which object –specify: handler to process the event Event Example Alert click on specific element –embed into HTML/


JavaScript Making Web pages come alive. Objectives Be able to read JavaScript scripts Be able to write JavaScript scripts.

-respond to users actions –onmouseover –onmouseout –onload –onunload Event handlers are put inside corresponding HTML tags. Not inside … Case onClick="alert (You clicked the button!);" The underlined parts are HTML The quoted string is JavaScript onClick –The Java naming convention is easier to read. –This is fine in HTML, but an error if it occurs in JavaScript. JavaScript is case sensitive. HTML is not. Please note: Since/


22.12.2015Jaana Holvikivi 1 Introduction to Javascript Jaana Holvikivi Metropolia.

in JavaScript  Numbers 0.44  Strings document.write (”greeting"+mj); in quotations ( or ")  Null”empty"  String literals alert("I am an alert box!! Man!"); when HTML is not in/button is clicked onunload The user exits the page setTimeout(), clearTimeout()timer is activated 22.12.2015Jaana Holvikivi22 Event: onload() & getElementById function process() {var string; string=" " + " Black " + " /OO code with error handling, instance methods, static methods and type hierarchies  Versatile use of functions /


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