1. Making AJAX Easy with jQuery Chris Renner Health Systems Analyst Programmer & Informatics Manager VUMC Office of Grants & Contracts Management October 18, 2010

2. Agenda What is AJAX? What is jQuery? Demonstration/Tutorial Resources Q&A

3. What is AJAX? Asynchronous JavaScript And XML A bundle of technologies used together to enhance user experience by altering displayed information on a web page without a page refresh. Employs HTML, CSS and JavaScript on client (browser) side, plus any one of a number of server-side technologies (e.g. PHP, ASP, etc).

4. AJAX visual model Browser Window (current page) An event triggers browser to open second connection to server (XMLHTTP request) Server side script processes input and outputs back to browser Browser routes the output back to current window JavaScript captures the output and does something cool in the current window

5. What is jQuery? A “JavaScript Library” that simplifies HTML and document traversing, event handling, animating, and AJAX interactions. A short hand for writing JavaScript with fewer lines of code do to the same things. “Write less, do more” Most widely adopted (Google, Dell, BofA, Digg, WordPress, Drupal, others), in use by 1/3 of top 10,000 websites.

6. jQuery Syntax Examples Get value by ID - JavaScript: var foo = document.getElementById(‘bar’).value; - jQuery: var foo = $(‘#bar’).val(); Daisy Chaining $(“#myDiv”).addClass(“myClass”).css(‘font- weight’, ‘bold’).fade(‘slow);

7. XMLHTTP Request with JavaScript var req; function loadXMLDoc(url) { req = false; // branch for native XMLHttpRequest object if(window.XMLHttpRequest && !(window.ActiveXObject)) { try { req = new XMLHttpRequest(); } catch(e) { req = false; } // branch for IE/Windows ActiveX version } else if(window.ActiveXObject) { try { req = new ActiveXObject("Msxml2.XMLHTTP"); } catch(e) { try { req = new ActiveXObject("Microsoft.XMLHTTP"); } catch(e) { req = false; } if(req) { req.onreadystatechange = processReqChange; req.open("GET", url, true); req.send(""); }

8. XMLHTTP Request with jQuery $.ajax({ type: "POST", url: "some.php", data: “city=Nashville", success: function(msg){ alert( "Data Saved: " + msg ); } });

9. Tutorial/Demo AJAX auto-complete

10. Resources Beginning Ajax with PHP, Lee Babin, Apress, Amazon id: 1590596676 http://www.jQuery.com W3chools AJAX tutorial: http://www.w3schools.com/Ajax/Default.Asp

11. Demo Q&A Any questions?

12. Find Me Phone: 2-7404 Email: chris.renner@vanderbilt.edu Dept Website: http://www.mc.vanderbilt.edu/gcm Web Development Blog: http://www.chrisrenner.com