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Created by Dr. Xi on August 31, 2008 20:43:44    Last update: January 22, 2011 12:48:08
It's probably more useful to make the JavaScript executor a bookmarklet. That way it gains access to the page on which it is invoked. Therefore, more helpful while debugging. Here's the code: <html> <body> <a href="javascript:(funct... Or, you can add this link to your bookmarks, name it "JS Executor". For a full featured JavaScript console, you may need Jash
Created by James on July 04, 2009 16:30:40    Last update: January 11, 2011 21:21:59
If you are looking for a solution for a progress bar, I direct you to the following resources: Bare Naked App provides a simple and elegant solution based on pure CSS with two images. You control the percentage of completion through the background-position attribute of the CSS. HTML: <img src="/images/percentImage.png" alt="... CSS: img.percentImage { background: white url(/imag... Images: (percentImage.png) (percentImage_back.png) WebAppers extended the above solution with JavaScript. They also added several colored images: JQuery UI has a built-in progress bar widget. However, if you want to get to understand some of the foobar needed to get CSS to work (in general) through this example, stay with me for the rest of this note. Initially I was thinking, a progress bar should be easy: just make...
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 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 Dr. Xi on September 07, 2008 22:10:21    Last update: September 07, 2008 22:15:51
When you use window.open to open a page in a new browser window, the new window is not modal, i.e., focus on the new window can be lost when the parent window is clicked. IE provides window.showModalDialog but it doesn't have the full power of a real browser window, and it's IE specific. This is a JavaScript that makes the popup window modal. The central trick is to check focus periodically with window.setInterval and request focus when it's lost. In IE, when an input on the page gets focus, the window thinks that it lost focus and requests focus back, thus taking focus away from any input fields - making it impossible to enter data into input fields in the modal dialog. This problem is...
Created by Dr. Xi on September 01, 2008 01:01:59    Last update: September 02, 2008 15:55:05
In JavaScript, null is not the same as "undefined". The value null is an object, while "undefined" is, well, undefined. However, for undefined variable a , if (a){...} throws exception, but if (window.a) {...} returns false , even though they are the same thing! // 1. for undefined variable a, typeof functio...