Recent Notes

Displaying keyword search results 1 - 9
Created by James on May 03, 2012 14:54:46    Last update: May 03, 2012 14:54:46
History.js gracefully supports the HTML5 History/State APIs (pushState, replaceState, onPopState) in all browsers. For HTML4 browsers it will revert back to using the old onhashchange functionality. All major browsers are supported. This is a simple test page to get started: <html> <head> <title>Test History</title> ... Note: state url must be provided for IE to generate a unique hash. YOu can prefix the state url with '?' ('#' does not work).
Created by James on April 24, 2012 13:50:05    Last update: April 24, 2012 13:50:05
The this object can be changed when calling a JavaScript function with func.call(theObject) . This is an example: <!DOCTYPE html> <html> <head> <title>jQu... The JavaScript console logs: [Global log] this is: [object Window] [log.cal...
Created by James on January 10, 2011 12:35:53    Last update: November 04, 2011 19:28:03
The events mouseover and mouseout are fired when the mouse enters/leaves the element where the event handlers are registered, and any nested elements which do not handle these events (because of event bubbling ). The events mouseenter and mouseleave are fired only when the mouse enters/leaves the specified element. Nested elements do not come into play. This following is a test page. You need Firebug to view the console output. Or use the JavaScript Executor bookmarklet. If none of these are available, an alert will popup (but you won't be able to fully test with alert.). <!DOCTYPE HTML> <html> <head> <title>jQu... For the above test page, when you move the mouse through both the outer and inner areas of the mouseover/mouseout rectangle, the output is...
Created by James on October 11, 2010 19:01:28    Last update: January 11, 2011 20:38:56
Test page (click the "new window" icon to see the transition): <!DOCTYPE html> <html> <head> <title>jQu...
Created by James on September 07, 2010 03:11:39    Last update: January 11, 2011 20:28:33
I didn't know how hard it was to vertically align something to the middle until I had to do it. An excellent writeup about the various techniques (or should I say hacks?) to achieve this is here: http://blog.themeforest.net/tutorials/vertical-centering-with-css/ Here I present a technique with the help of jQuery. To make it simple, what I'm doing is to display a single line of text in the middle of the page instead of at the top. The markup is made simple because the logic is moved to JavaScript. There are two requirements to make this work: The parent container uses relative positioning jQuery code added to re-position the content with absolute positioning <!doctype html> <html> <head> <title>Vert... For some reason, the following code did not work although...
Created by Dr. Xi on August 21, 2007 21:25:58    Last update: January 10, 2011 22:19:09
You can grab some animated icons here: http://mentalized.net/activity-indicators/ . And here's some code to demonstrate how to use such an icon. <html> <head> <script language="JavaScript"... However, if you use Ajax and send a synchronous request, the icon won't show up at all, i.e., the following code doesn't work: function eventHandler() { startBusy(); ... This works: function eventHandler() { startBusy(); ...
Created by James on June 30, 2010 19:04:45    Last update: July 03, 2010 21:24:33
Technically, file upload cannot be handled by Ajax, because XMLHttpRequest (XHR) does not handle file inputs. All techniques not using Flash rely on an invisible iframe as the upload form submit target. JavaScript then grabs the response content from the iframe and present it, giving the same illusion as Ajax. webtoolkit AIM The technique by webtoolkit is very simple. It involves 3 simple steps: include the AIM script, implement the start/finish JavaScript functions, and add an onsubmit handler to the normal file upload form. The hooked up form looks like: <head> <script type="text/javascript" src="webt... The AIM script is also quite simple: /** * * AJAX IFRAME METHOD (AIM) * http... The above code only supports HTML responses. In order to support JSON responses, the above...
Created by James on June 30, 2010 20:14:28    Last update: July 03, 2010 18:41:12
The HTML page <!DOCTYPE html> <html> <head> <title>jQu... Client Side Code // called before upload submit function sta... Server Side Code Using Apache Commons FileUpload as example. Upload code (responds to fileUpload.do ): final HttpSession session = httpServletRequest... Progress code (responds to uploadProgress.do ): HttpSession session = httpServletRequest.getSe...
Created by Dr. Xi on December 12, 2007 20:30:01    Last update: December 12, 2007 20:32:23
This is a script to tail a log file through the web browser. It uses AJAX, apache web server, mod_python, UNIX utilities tail (requires the --lines switch) and wc . The log file may reside on the web server or any other host accessible from the web server through SSH. Although it's written in python, it should be easy to port to other languages such as Perl. Apache httpd.conf : LoadModule python_module modules/mod_python.so ... Python script: import time, os from os.path import basename ...