Introduction, Technologies included in ajax,
Ajax Evolution,
Pro’s and Con’s,
Beginners Problem?,
Types and choices of request,
Ajax on hands (Example),
Global Ajax Event Handlers,
Helper Functions,
Low Level interface,
Shorthand Methods for Ajax request.
Ajax stands for Asynchronous JavaScript and Xml. Ajax is not a single technology, but a group of technologies. HTML and CSS can be used in combination to mark up and style information. The DOM is accessed with JavaScript to dynamically display, and allow the user to interact with, the information presented. JavaScript and the XMLHttpRequest object provide a method for exchanging data asynchronously between browser and server to avoid full page reloads.
Bally Chohan IT Solution is an UK based IT Agency that provides IT services such as Web Development, Web Designing, E-commerce development etc.
Introduction, Technologies included in ajax,
Ajax Evolution,
Pro’s and Con’s,
Beginners Problem?,
Types and choices of request,
Ajax on hands (Example),
Global Ajax Event Handlers,
Helper Functions,
Low Level interface,
Shorthand Methods for Ajax request.
Ajax stands for Asynchronous JavaScript and Xml. Ajax is not a single technology, but a group of technologies. HTML and CSS can be used in combination to mark up and style information. The DOM is accessed with JavaScript to dynamically display, and allow the user to interact with, the information presented. JavaScript and the XMLHttpRequest object provide a method for exchanging data asynchronously between browser and server to avoid full page reloads.
Bally Chohan IT Solution is an UK based IT Agency that provides IT services such as Web Development, Web Designing, E-commerce development etc.
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
For more information, visit-www.vavaclasses.com
How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
Students, digital devices and success - Andreas Schleicher - 27 May 2024..pptxEduSkills OECD
Andreas Schleicher presents at the OECD webinar ‘Digital devices in schools: detrimental distraction or secret to success?’ on 27 May 2024. The presentation was based on findings from PISA 2022 results and the webinar helped launch the PISA in Focus ‘Managing screen time: How to protect and equip students against distraction’ https://www.oecd-ilibrary.org/education/managing-screen-time_7c225af4-en and the OECD Education Policy Perspective ‘Students, digital devices and success’ can be found here - https://oe.cd/il/5yV
Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
Ethnobotany and Ethnopharmacology:
Ethnobotany in herbal drug evaluation,
Impact of Ethnobotany in traditional medicine,
New development in herbals,
Bio-prospecting tools for drug discovery,
Role of Ethnopharmacology in drug evaluation,
Reverse Pharmacology.
The Art Pastor's Guide to Sabbath | Steve ThomasonSteve Thomason
What is the purpose of the Sabbath Law in the Torah. It is interesting to compare how the context of the law shifts from Exodus to Deuteronomy. Who gets to rest, and why?
This is a presentation by Dada Robert in a Your Skill Boost masterclass organised by the Excellence Foundation for South Sudan (EFSS) on Saturday, the 25th and Sunday, the 26th of May 2024.
He discussed the concept of quality improvement, emphasizing its applicability to various aspects of life, including personal, project, and program improvements. He defined quality as doing the right thing at the right time in the right way to achieve the best possible results and discussed the concept of the "gap" between what we know and what we do, and how this gap represents the areas we need to improve. He explained the scientific approach to quality improvement, which involves systematic performance analysis, testing and learning, and implementing change ideas. He also highlighted the importance of client focus and a team approach to quality improvement.
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
Instructions for Submissions thorugh G- Classroom.pptxJheel Barad
This presentation provides a briefing on how to upload submissions and documents in Google Classroom. It was prepared as part of an orientation for new Sainik School in-service teacher trainees. As a training officer, my goal is to ensure that you are comfortable and proficient with this essential tool for managing assignments and fostering student engagement.
Instructions for Submissions thorugh G- Classroom.pptx
Ajax ppt
1. AJAX Ajax (shorthand for asynchronous JavaScript and XML) is a group of interrelated web development techniques used on the client-side to create interactive web applications. With Ajax, web applications can retrieve data from the server asynchronously in the background without interfering with the display and behavior of the existing page. The use of Ajax techniques has led to an increase in interactive or dynamic interfaces on web pages. Data is usually retrieved using the XMLHttpRequest object. Despite the name, the use of XML is not actually required, nor do the requests need to be asynchronous. Like DHTML and LAMP, Ajax is not a technology in itself, but a group of technologies. Ajax uses a combination of HTML and CSS to mark up and style information. The DOM is accessed with JavaScript to dynamically display, and to allow the user to interact with the information presented. JavaScript and the XMLHttpRequest object provide a method for exchanging data asynchronously between browser and server to avoid full page reloads .
3. AJAX is Based on Internet Standards AJAX is based on internet standards, and uses a combination of: * XMLHttpRequest object (to exchange data asynchronously with a server) * JavaScript/DOM (to display/interact with the information) * CSS (to style the data) * XML (often used as the format for transferring data) lamp AJAX applications are browser- and platform-independent! Google Suggest AJAX was made popular in 2005 by Google, with Google Suggest. Google Suggest is using AJAX to create a very dynamic web interface: When you start typing in Google's search box, a JavaScript sends the letters off to a server and the server returns a list of suggestions.
4. AJAX Example Explained The AJAX application above contains one div section and one button. The div section will be used to display information returned from a server. The button calls a function named loadXMLDoc(), if it is clicked: <html> <body> <div id="myDiv"><h2>Let AJAX change this text</h2></div> <button type="button" onclick="loadXMLDoc()">Change Content</button> </body> </html> Next, add a <script> tag to the page's head section. The script section contains the loadXMLDoc() function: <head> <script type="text/javascript"> function loadXMLDoc() { .... AJAX script goes here ... } </script> </head>
5. AJAX XMLHttpRequest AJAX - Create an XMLHttpRequest Object The XMLHttpRequest Object All modern browsers support the XMLHttpRequest object (IE5 and IE6 uses an ActiveXObject). The XMLHttpRequest object is used to exchange data with a server behind the scenes. This means that it is possible to update parts of a web page, without reloading the whole page.
6. Create an XMLHttpRequest Object All modern browsers (IE7+, Firefox, Chrome, Safari, and Opera) has a built-in XMLHttpRequest object. Syntax for creating an XMLHttpRequest object: xmlhttp=new XMLHttpRequest(); Old versions of Internet Explorer (IE5 and IE6) uses an ActiveX Object: xmlhttp=new ActiveXObject("Microsoft.XMLHTTP"); To handle all modern browsers, including IE5 and IE6, check if the browser supports the XMLHttpRequest object. If it does, create an XMLHttpRequest object, if not, create an ActiveXObject: Example if (window.XMLHttpRequest) {// code for IE7+, Firefox, Chrome, Opera, Safari xmlhttp=new XMLHttpRequest(); } else {// code for IE6, IE5 xmlhttp=new ActiveXObject("Microsoft.XMLHTTP"); }
7. AJAX - Send a Request To a Server Send a Request To a Server To send a request to a server, we use the open() and send() methods of the XMLHttpRequest object: xmlhttp.open("GET","ajax_info.txt",true); xmlhttp.send(); Method Description open(method,url,async) Specifies the type of request, the URL, and if the request should be handled asynchronously or not. method: the type of request: GET or POST url: the location of the file on the server async: true (asynchronous) or false (synchronous) send(string) Sends the request off to the server. string: Only used for POST requests
8. GET or POST? GET is simpler and faster than POST, and can be used in most cases. However, always use POST requests when: * A cached file is not an option (update a file or database on the server) * Sending a large amount of data to the server (POST has no size limitations) * Sending user input (which can contain unknown characters), POST is more robust and secure than G
9. GET Requests A simple GET request: Example xmlhttp.open("GET","demo_get.asp",true); xmlhttp.send(); In the example above, you may get a cached result. To avoid this, add a unique ID to the URL: Example xmlhttp.open("GET","demo_get.asp?t=" + Math.random(),true); xmlhttp.send(); If you want to send information with the GET method, add the information to the URL: Example xmlhttp.open("GET","demo_get2.asp?fname=Henry&lname=Ford",true); xmlhttp.send();
10. POST Requests A simple POST request: Example xmlhttp.open("POST","demo_post.asp",true); xmlhttp.send(); To POST data like an HTML form, add an HTTP header with setRequestHeader(). Specify the data you want to send in the send() method: Example xmlhttp.open("POST","ajax_test.asp",true); xmlhttp.setRequestHeader("Content-type","application/x-www-form-urlencoded"); xmlhttp.send("fname=Henry&lname=Ford");
11. The url - A File On a Server The url parameter of the open() method, is an address to a file on a server: xmlhttp.open("GET","ajax_test.asp",true); The file can be any kind of file, like .txt and .xml, or server scripting files like .asp and .php (which can perform actions on the server before sending the response back). Asynchronous - True or False? AJAX stands for Asynchronous JavaScript and XML, and for the XMLHttpRequest object to behave as AJAX, the async parameter of the open() method has to be set to true: xmlhttp.open("GET","ajax_test.asp",true); Sending asynchronously requests is a huge improvement for web developers. Many of the tasks performed on the server are very time consuming. Before AJAX, this operation could cause the application to hang or stop. With AJAX, the JavaScript does not have to wait for the server response, but can instead: * execute other scripts while waiting for server response * deal with the response when the response ready
12. Async=true When using async=true, specify a function to execute when the response is ready in the onreadystatechange event: Example xmlhttp.onreadystatechange=function() { if (xmlhttp.readyState==4 && xmlhttp.status==200) { document.getElementById("myDiv").innerHTML=xmlhttp.responseText; } } xmlhttp.open("GET","ajax_info.txt",true); xmlhttp.send(); Async=false To use async=false, change the third parameter in the open() method to false: xmlhttp.open("GET","ajax_info.txt",false); Using async=false is not recommended, but for a few small requests this can be ok. Remember that the JavaScript will NOT continue to execute, until the server response is ready. If the server is busy or slow, the application will hang or stop. Note: When you use async=false, do NOT write an onreadystatechange function - just put the code after the send() statement: Example xmlhttp.open("GET","ajax_info.txt",false); xmlhttp.send(); document.getElementById("myDiv").innerHTML=xmlhttp.responseText;
13. AJAX - Server Response Server Response To get the response from a server, use the responseText or responseXML property of the XMLHttpRequest object. Property Description responseText get the response data as a string responseXML get the response data as XML data The responseText Property If the response from the server is not XML, use the responseText property. The responseText property returns the response as a string, and you can use it accordingly: Example document.getElementById("myDiv").innerHTML=xmlhttp.responseText;
14. The responseXML Property If the response from the server is XML, and you want to parse it as an XML object, use the responseXML property: Example Request the file cd_catalog.xml and parse the response: xmlDoc=xmlhttp.responseXML; var txt=""; x=xmlDoc.getElementsByTagName("ARTIST"); for (i=0;i<x.length;i++) { txt=txt + x[i].childNodes[0].nodeValue + "<br />"; } document.getElementById("myDiv").innerHTML=txt;
15. AJAX - The onreadystatechange Event The onreadystatechange event When a request to a server is sent, we want to perform some actions based on the response. The onreadystatechange event is triggered every time the readyState changes. The readyState property holds the status of the XMLHttpRequest. Three important properties of the XMLHttpRequest object: Property Description onreadystatechange Stores a function (or the name of a function) to be called automatically each time the readyState property changes readyState Holds the status of the XMLHttpRequest. Changes from 0 to 4: 0: request not initialized 1: server connection established 2: request received 3: processing request 4: request finished and response is ready status 200: "OK" 404: Page not found
16. xmlhttp.onreadystatechange=function() Example { if (xmlhttp.readyState==4 && xmlhttp.status==200) { document.getElementById("myDiv").innerHTML=xmlhttp.responseText; } } When readyState is 4 and status is 200, the response is ready:
17. Using a Callback Function A callback function is a function passed as a parameter to another function. If you have more than one AJAX task on your website, you should create ONE standard function for creating the XMLHttpRequest object, and call this for each AJAX task. The function call should contain the URL and what to do on onreadystatechange (which is probably different for each call): Example function myFunction() { loadXMLDoc("ajax_info.txt",function() { if (xmlhttp.readyState==4 && xmlhttp.status==200) { document.getElementById("myDiv").innerHTML=xmlhttp.responseText; } }); }
20. AJAX ASP/PHP Example Example Start typing a name in the input field below: First name: Suggestions:
21. The PHP File Below is the code above rewritten in PHP. Note: To run the example in PHP, change the value of the url variable (in the HTML file) from "gethint.asp" to "gethint.php". <?php // Fill up array with names $a[]="Anna"; $a[]="Brittany"; $a[]="Cinderella"; $a[]="Diana"; $a[]="Eva"; $a[]="Fiona"; $a[]="Gunda"; $a[]="Hege"; $a[]="Inga"; $a[]="Johanna"; $a[]="Kitty"; $a[]="Linda"; $a[]="Nina"; $a[]="Ophelia"; $a[]="Petunia"; $a[]="Amanda"; $a[]="Raquel";
22. $a[]="Cindy"; $a[]="Doris"; $a[]="Eve"; $a[]="Evita"; $a[]="Sunniva"; $a[]="Tove"; $a[]="Unni"; $a[]="Violet"; $a[]="Liza"; $a[]="Elizabeth"; $a[]="Ellen"; $a[]="Wenche"; $a[]="Vicky"; //get the q parameter from URL $q=$_GET["q"]; //lookup all hints from array if length of q>0 if (strlen($q) > 0) { $hint=""; for($i=0; $i<count($a); $i++) { if (strtolower($q)==strtolower(substr($a[$i],0,strlen($q)))) { if ($hint=="")
23. $hint=$a[$i]; } else { $hint=$hint." , ".$a[$i]; } } } } // Set output to "no suggestion" if no hint were found // or to the correct values if ($hint == "") { $response="no suggestion"; } else { $response=$hint; } //output the response echo $response; ?>
24. AJAX Database Example Example Explained - The showCustomer() Function When a user selects a customer in the dropdown list above, a function called "showCustomer()" is executed. The function is triggered by the "onchange" event: function showCustomer(str) { if (str=="") { document.getElementById("txtHint").innerHTML=""; return; } if (window.XMLHttpRequest) {// code for IE7+, Firefox, Chrome, Opera, Safari xmlhttp=new XMLHttpRequest(); } else {// code for IE6, IE5 xmlhttp=new ActiveXObject("Microsoft.XMLHTTP"); } xmlhttp.onreadystatechange=function() { if (xmlhttp.readyState==4 && xmlhttp.status==200) { document.getElementById("txtHint").innerHTML=xmlhttp.responseText; } } xmlhttp.open("GET","getcustomer.asp?q="+str,true); xmlhttp.send();
25. The AJAX Server Page The page on the server called by the JavaScript above is an ASP file called "getcustomer.asp". The server file could easily be rewritten in PHP, or some other server languages. Look at a corresponding example in PHP. The source code in "getcustomer.asp" runs a query against a database, and returns the result in an HTML table: <% response.expires=-1 sql="SELECT * FROM CUSTOMERS WHERE CUSTOMERID=" sql=sql & "'" & request.querystring("q") & "'" set conn=Server.CreateObject("ADODB.Connection") conn.Provider="Microsoft.Jet.OLEDB.4.0" conn.Open(Server.Mappath("/db/northwind.mdb")) set rs=Server.CreateObject("ADODB.recordset") rs.Open sql,conn response.write("<table>") do until rs.EOF for each x in rs.Fields response.write("<tr><td><b>" & x.name & "</b></td>") response.write("<td>" & x.value & "</td></tr>") next rs.MoveNext loop response.write("</table>") %>
26. AJAX XML Example AJAX can be used for interactive communication with an XML file. The following example will demonstrate how a web page can fetch information from an XML file with AJAX: Example Get CD info Example Explained - The stateChange() Function When a user clicks on the "Get CD info" button above, the loadXMLDoc() function is executed. The loadXMLDoc() function creates an XMLHttpRequest object, adds the function to be executed when the server response is ready, and sends the request off to the server. When the server response is ready, an HTML table is built, nodes (elements) are extracted from the XML file, and it finally updates the txtCDInfo placeholder with the HTML table filled with XML data:
