My screencasts are consistently popular, so I thought I’d create another which talks about a slick usage of my favourite JS framework, Ext JS. In this screencast, I show how to display images stored on a server directory using a PHP JSON backend which provides data to an Ext DataView. I then allow deletion of these images and uploading of new images in an Ajax-style fashion, with no page refreshes.

This approach can be useful when editing a complex form – the details of a product you’re selling on your ecommerce site, for example – and you want to upload images without having to repopulate the other form fields when the page reloads, as it would with a standard file upload.

You can view the screencast here or download the full download the source code. I use loeppky’s BrowseButton extension for Ext 2, which you can read more about at his forum post. I hope you enjoy the screencast which is provided in association with Plastiscenic Ltd.

I’ve blogged before about the enabling features of Monorail and Active Record, part of the Castle stack. Another piece of software which is making my development life a pleasure is ExtJS – a collection of javascript goodies created by Jack Slocum and his team – and when these three things come together, watch that coding fly…. I’ve created a screencast in which I demonstrate how easy it is to build a paging, sorting, filtering, AJAX-powered grid using ExtJS and Castle, and you can watch it here. It’s 20 minutes long but filled with goodness – and a couple of hacks (forgive me . Don’t forget to check out all my past screencasts too.

UPDATE: As requested in the comments, you can MonorailExt1 VS Project directory of this.

I’ve been using libraries such as NewtonSoft’s JSON.NET or AjaxPro to serialize a class to JSON. There’s something about my approach which didn’t really sit too well, and C# 3 has an elegant solution.
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JSON Validity Checker

June 12th 2006, 12:31 pm in Ajax, Web.

This is simple I know, but I couldn’t actually find an online version of it. A JSON Checker, just paste in your JSON string and hit the button.

If it’s parsable then it’ll let you know. If it’s not, then it tells you “nope”. Heads up to Jay Kimble for the impetus.

Via Roy Osherove, I found out about an open source project which allows you to access SQL Server over the web via an Enterprise Manager style interface. It supports database providers, so it could work with MySQL too. Visual WebGui Enterprise Manager.

Michael Schwartz reports that certain aspects of Microsoft’s flagship web development, www.live.com, are pretty slow. He speculates that is is their new Atlas framework which is causing this, but Scott Guthrie jumps in on the comments of the post to correct him – Scott says that the XML parsing of RSS feeds is the slow part of live.com This reinforces Michael’s message regarding the strange decision by MS to use an XML scripting language (I’m not familiar with this) rather than JSON…

Live.com’s image search is excellent, if slightly clunky. Their search is good but not responsive enough – and it removes my middle click functionality in Firefox. And the portal / live homepage thing, it’s just like all of the other ajax portal startups – a novelty. Just like the gadgets on the Vista sidebar strangely enough!

ComfortASP is an AJAX like framework for ASP.NET which replaces normal postbacks with an XMLHTTPRequest based server call. The page, or sections of the page, will then be automagically replaced by the server response using javascript. If javascript is turned off then the whole thing degrades.

The framework includes some nice controls, including one to scroll to a point on the page when the server response returns. My main concern is that by using this framework, navigating between pages doesn’t change the URL in the address bar. It also seems to break my back button in Firefox 1.5.

That’s a shame because this is a great idea – abstracting AJAX to the point where you don’t have to worry about it at all. But I think there are limitations here that would stop me from using ComfortASP in anger.

In other news, here’s a post on doing multiple concurrent XMLHTTPRequests from a single page.

Lace is a framework for building web communication applications such as chatroom. The demo illustrates the usefulness of such a platform, and even better, Brett now plans on keeping 0.2 simple and reusable.

A chat system for any website? Not exactly, but this great bit of Ajax innovation has seriously got me thinking