Comments on: Deciding What AJAX Programming Style to Use

By: Joshua Eichorn

Joshua Eichorn — Thu, 15 Mar 2007 16:30:55 +0000

If your reloading the majority of the page, you don’t gain a lot by using AJAX, you could just use a meta refresh tag, or refresh the page using a bit of JS.

This might be a case where moving just the data that is updated using an RPC style call might make a lot of sense. You get the data and then update your timestamp and change status images using the DOM. Im guessing the your actually only updating maybe 10-20 pieces of data well under 1k where a full page reload might be 20K or 30K. So you could get some huge bandwith savings.

So too sum it up, if you need to save bandwidth and can make an RPC style approach work then AJAX should work for you.

If you don’t need to save the bandwidth or you don’t want to mess with RPC AJAX then don’t use AJAX at all just refresh the entire page.

By: Sudeep

Sudeep — Thu, 15 Mar 2007 08:13:27 +0000

Hi ,

I have a problem deciding whether to use Ajax for a situation like the whole page has to be refreshed . We are designing a dashboard which gives the status of the clients worldwide with green light indicating that the client is working fine and the red indicating that it has failed ,I need to poll the server for the status every 10 mins and update the dashboard accordingly .It also displays the last response time of each client so the time option also has to be updated .
Can I use AJAX for this situation .Does it make any difference using AJAX in this case ……….

Thanks and Regards,
Sudeep

By: Jan Schneider

Jan Schneider — Thu, 04 Jan 2007 23:17:09 +0000

I didn’t think about the different AJAX techniques we use before I read your comments. But it’s a nice distinction and we actually use chunks and widgets in DIMP (http://www.horde.org/dimp/). I guess the different methods have been chosen correctly intuitively. We use chunks when changing larger parts of the interface like displaying a message, opening a compose view etc. Widgets are created dynamically from JSON objects or loaded as static HTML chunks and use callbacks to update themselves, e.g. in the folder listings, mailbox views and similar.

By: Laurent

Laurent — Thu, 04 Jan 2007 23:00:14 +0000

Hey Stan,

Just out of curiosity, what kind of web-based education software are you guys making?

By: Stan

Stan — Thu, 04 Jan 2007 18:47:35 +0000

Josh,
I’ve been working for a company that writes web-based education software in Java and they’re progressively moving their app over to being more AJAX driven. Unfortunately, the preference there is that we use DOM to make any alterations to the page. We do this even when chunks would save us a lot of time and speed on the browser. Error handling in struts sucks - but the one advantage I’ve had thus far with the way we do it there is returning error objects to the client Javascript and dealing with it there. I’ve not yet seen a clean and easy way of handling errors with chunking. Part of the struggle I’ve been faced with too is that we’re limited to using Prototype and each AJAX call results in a separate action file. Pain in the arsh! Now on the other hand with some non-profit work I do in php I use HTML_AJAX most of the time, there though I use it mostly to trigger events, throwing flags on a database table row - when I do need to handle large blocks of HTML I handle them in chunks.

Pax,
- Stan

By: Joshua Eichorn

Joshua Eichorn — Thu, 04 Jan 2007 17:40:45 +0000

Ivo:

It is an argument for using AJAX page chunks even for things like a live grid. But im trying to stay focused on the development side. One approach might be faster but as long as whatever approach you use is fast enough does relative speed really matter?

By: Ivo Jansch

Ivo Jansch — Thu, 04 Jan 2007 17:29:56 +0000

Joshua,

I think this link is relevant to your post; it performs a banchmark of innerhtml and dom methods for manipulating elements in the resulting page:

http://www.quirksmode.org/dom/innerhtml.html

By: Joshua Eichorn

Joshua Eichorn — Thu, 04 Jan 2007 16:46:51 +0000

Chris:
I’m not sure if I covered it well enough in this post, but a big part of my point is that the complexity of those other patterns usually means they are worse approaches then just doing page chunks. I find a lot of times I tend to look at a fancy solution first, start implmenting it and then realize im just wasting time. I’m seldom the only person working on a project these days and when I do something complex I’m the only one who can support it, and in many cases understand it. Its not fun to be the choke point on both the backend code and the frontend because of all the AJAX you’ve added.

My book covers a bunch of different patterns in the example applications that are built. It also shows off a bunch of basic stategies in a more abstract sense. But the books focus isn’t on being a patterns book so you won’t see a lot of the contrast and comparision between the different approaches.

By: Chris Hartjes

Chris Hartjes — Thu, 04 Jan 2007 16:32:51 +0000

Hey Joshua,

Until my Javascript skills get to a higher level, I do things the AJAX page chunk way. Things like replacing the form with a thank you message after submitting valid information, click-sortable grids of website statistics. Given the nature of the beast (find a bit of AJAX goodness that someone else created, modify it for your own needs) I think that is probably the default mode for most AJAX work.

I’m sure at some point I will encounter something I will want to do that will require a lot more Javascript so I will move to more advanced techniques. Not to shill someone else’s book, but “Ajax Design Patterns” shows lots of examples of things that would cause me to break out of the AJAX page chunk mode. I just have to find an excuse to use one.

I’m curious: does your book cover similar content?