Javascript / DHTML Web Log Entries
Using Base64 Canvas Data In jQuery To Create ColdFusion Images
Posted: March 10, 2010 at 9:49 AM by Ben Nadel
Last week, I explored the HTML Canvas element for the first time. In that exploration, I created a "finger painting" demo for the iPhone that would post drawing commands to the server where the image would be re-created as a PNG in ColdFusion. That was a nice approach because it gave me some flexibility in how the ColdFusion image was created (u... read more »
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Translating Global jQuery Event Coordinates To A Local Context
Posted: March 9, 2010 at 9:31 AM by Ben Nadel
When you use jQuery to capture mouse events (mousedown, mouseup, click, etc.), the jQuery Event object contains the X and Y coordinates of the mouse position at the time the event was triggered. These coordinates, while somewhat different in each browser, have been standardized by jQuery to be available in the pageX and pageY properties . No matt... read more »
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jQuery Mouse Events: PageX/Y vs. ClientX/Y
Posted: March 8, 2010 at 9:19 AM by Ben Nadel
When I first starting playing with jQuery events, a lot of what I learned about the jQuery Event object was through trial and error. While I could be remembering incorrectly, I used to find that the jQuery documentation was good at describing the event handlers, but not so good at describing the event object; as such, while I knew that the jQuery ... read more »
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Drawing On The iPhone Canvas With jQuery And ColdFusion
Posted: March 5, 2010 at 8:44 AM by Ben Nadel
The HTML Canvas element is something that I've known about for a long time but never actually looked at until yesterday. The Canvas element is just what it sounds like - a surface on which we can programmatically render graphics and shapes. After seeing some really cool canvas-based demos floating around on Twitter, I decided that it was finally t... read more »
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FLEX On jQuery: Turning HTML Links Into Standard UI Elements
Posted: March 3, 2010 at 8:39 PM by Ben Nadel
In my first "FLEX on jQuery" blog post yesterday , I talked with Javier Julio about some of the similarities and differences between FLEX applications and rich jQuery applications. As we talked, one of the patterns that I began to see was the significant difference in the inherent power of "link" elements in the two different technologies. I sa... read more »
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FLEX On jQuery: The Relative Power Of Link Elements
Posted: March 3, 2010 at 10:17 AM by Ben Nadel
Mentally, I am still very much in the web application world of the traditional client-server request-response life cycle. I think in terms of page requests and view rendering; and, as my ability to code complex jQuery applications increases, I fear that my understanding of client-side architecture "best practices" is not keeping up. After a lot of... read more »
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Experimenting With jQuery's Queue() And Dequeue() Methods
Posted: March 2, 2010 at 9:10 AM by Ben Nadel
jQuery comes with a number of built-in animation methods like slideUp() and slideDown(). While these appear to be packaged in their own methods, many of them are powered internally by the animate() method. And while the animate() method handles many of the effects, a string of sequential animations is controlled internally by jQuery's queuing mech... read more »
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Be Careful When Including Images In jQuery Auto-Suggest
Posted: February 26, 2010 at 10:20 AM by Ben Nadel
Yesterday at work, we ran into a very interesting problem involving a jQuery auto-suggest feature on one of our client sites. We had implemented auto-suggest on this particular site several times before and it had always proved to be very zippy and responsive. This time, however, the "suggest" page requests were taking 5, 6, sometimes 8 seconds to... read more »
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Using Appropriate Status Codes With Each API Response
Posted: February 24, 2010 at 10:11 AM by Ben Nadel
For a long time, I have thought about API request failures as falling into just two distinct categories: failure to communicate (ie. the server was down) or bad data (ie. invalid parameters). Failures to communicate with the server were out of my hands; as such, there was nothing I could do with those from a server standpoint. Requests with bad da... read more »
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Using jQuery's Animate() Step Callback Function To Create Custom Animations
Posted: February 19, 2010 at 10:56 AM by Ben Nadel
When I was reading the jQuery 1.4 Reference Guide over the weekend, it mentioned that jQuery's animate() method has a step callback function that gets called after each step of the animation has completed. Unfortunately, it didn't say anything more than this. I tried looking at the online documentation and it said the exact same thing. As such, ... read more »
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Traversal vs. Collection Filtering In jQuery
Posted: February 17, 2010 at 9:50 AM by Ben Nadel
When it comes to jQuery selectors, I tend to think in two different modes: collection filtering and traversal filtering. By that, I mean that I see filtering as happening at two different and distinct times in the selection process. With collection filtering, jQuery filters nodes only once it has compiled them into a collection. All filtering done... read more »
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Posting XML SOAP Requests With jQuery
Posted: February 16, 2010 at 10:10 AM by Ben Nadel
In the jQuery 1.4 Reference Guide by Karl Swedberg and Jonathan Chaffer , it is explained that the processData and contentType properties of a jQuery ajax() request can be adjusted to allow for XML document posts. Typically, AJAX data is serialized into a query string; but, if you set the processData property to false, the data property will be p... read more »
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jQuery forEach() Experiment For Branch-Wise Implicit Iteration
Posted: February 15, 2010 at 3:44 PM by Ben Nadel
This morning, in my post about the jQuery plugin, closestParents() , Dan G. Switzer, II had mentioned that it would be cool to have a forEach() construct in jQuery the way there are in other functional programming languages. I had never heard of forEach() before, but from what I gathered, it would allow jQuery to perform its implicit iteration ... read more »
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Selecting The Closest Parent On Multiple Nodes With The jQuery Plugin ClosestParents()
Posted: February 15, 2010 at 9:25 AM by Ben Nadel
Every now and then, I have a situation where I have a given set of nodes and I need to get particular ancestors of those nodes. jQuery currently provides three ways of accessing ancestors of a given collection: parent(), parents(), and parentsUntil(). Parent() gets the direct parent of each element in your collection; parents() gets all the ancest... read more »
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jQuery 1.4 Reference Guide By Karl Swedberg And Jonathan Chaffer
Posted: February 14, 2010 at 6:08 PM by Ben Nadel
If you're a web developer, chances are good that you are building your web applications using the jQuery Javascript library. And, if you're doing that, chances are, you're loving it; jQuery's appeal comes from, in no small part, that fact that it provides a tremendous amount of power with a very small, very manageable API. And, while this is obvio... read more »
