Archive for July, 2008

Cross-Site XHR Plugin Registry

Thursday, July 31st, 2008

Several new technologies are coming out for accessing resources from other sites. IE8 will include the XDomainRequest and the W3C is finishing the access control specification for enabling cross-site access for XMLHttpRequest, which will probably be implemented in next major release of all browsers, including Firefox. However, it will certainly take a long time for these new technologies to become pervasive enough to use them reliably and exclusively. Is there any way to leverage this technology immediately when these browsers are released? Yes! With Dojo’s new XHR plugin system, you can start making cross-site requests right away, using the new technologies when available, and a proxy server as a fallback, all while using the familiar dojo.xhr* methods. Your source code can still use this simple API while the registry can handle choosing the appropriate underlying transports for the situation.

(more…)

Protected Cross-Domain Authentication with JavaScript

Wednesday, July 30th, 2008

Google and Yahoo have JavaScript APIs that let you perform searches. Wikipedia has a JavaScript API that lets you grab data from its pages. These APIs can be accessed cross-domain with a transport method known as JSONP. JSONP works by allowing you add a script tag to your page which points to a URL on their server. The server outputs JavaScript that will call a method (defined as part of the query string in the URL), passing it JSON-formatted data.

You’ll notice that these services are read-only. I don’t currently know of any cross-domain JavaScript APIs that allow you to write data in any meaningful way. An example of this sort of data would be a way, through JavaScript, to update your status on a social networking web site.

(more…)

Interview on Dojo on Ajax, Comet, Bayeux, RIAs and the Dojo Toolbox

Wednesday, July 23rd, 2008

The Dojo Toolkit is a modular open source JavaScript library, designed to ease the rapid development of JavaScript or Ajax-based applications and web sites. InfoQ had a Q&A with Dylan Schiemann, CEO of SitePen and co-creator of the Dojo Toolkit, about AJAX, Comet, Bayeux, RIAs and the newly released Dojo Toolbox.

Check out the full interview at InfoQ.

Getting Started with Persevere Using Dojo

Wednesday, July 23rd, 2008

The Persevere server is an open source JSON application and storage server. Persevere pairs well with Dojo; the Dojo Data paradigm has a strong correlation to Persevere’s data storage structure. Virtually everything you can create or action you can perform with Dojo Data can be persisted in Persevere’s data storage including subobjects, arrays, circular references, and functions. Combining Persevere with Dojo allows you to rapidly develop simple database applications with create, read, update, and delete (CRUD) capabilities with minimal effort.

(more…)

window.name Transport

Tuesday, July 22nd, 2008

The window.name transport is a new technique for secure cross-domain browser based data transfer, and can be utilized for creating secure mashups with untrusted sources. window.name is implemented in Dojo in the new dojox.io.windowName module, and it is very easy to make web services available through the window.name protocol. window.name works by loading a cross-domain HTML file in an iframe. The HTML file then sets its window.name to the string content that should be delivered to the requester. The requester can then retrieve the window.name value as the response. The requested resource never has access to the requester’s environment (JavaScript variables, cookies, and DOM).

(more…)

IE 6 On the Way Out?

Monday, July 21st, 2008

It seems that the Dojo toolkit will continue supporting IE 6 for a long time to come as Dylan Schiemann, CEO of SitePen and co-creator of Dojo tells us: When first released, Internet Explorer 4.5, 5.5, and 6 radically improved the lives of web developers with cutting edge features, but it has been 7 years since IE 6 was released. Today, I estimate that developers collectively spend billions of dollars in salary working around buggy behavior in IE.

Check out the full article at InfoQ

Client/Server Model on the Web

Friday, July 18th, 2008

Prior to the popularity of the web, client/server applications often involved the creation of native applications which were deployed to clients. In this model, developers had a great deal of freedom in determining which parts of the entire client/server application would be in the client and which in the server. Consequently, very mature models for client/server development emerged, and often well designed optimal distribution of processing and logic could be achieved. When the web took off, the client was no longer a viable application platform, it was really more of a document viewer. Consequently the user interface logic existed almost entirely on the server. However, the web has matured substantially and has proven itself to be a reasonable application platform. We can once again start utilizing more efficient and well-structured client/server model design. There are certainly still technical issues, but we are in a position to better to build true client/server applications now.

(more…)

JSONQuery: Data Querying Beyond JSONPath

Wednesday, July 16th, 2008

A new data querying tool for has been added to Dojo 1.2. JSONQuery is a new module intended to succeed and improve upon the JSONPath module introduced in Dojo 1.1. JSONQuery provides a comprehensive set of data querying tools including filtering, recursive search, sorting, mapping, range selection, and flexible expressions with wildcard string comparisons and various operators.

JSONQuery provides safe evaluation with language agnostic expressions that prevents arbitrary code execution. It also uses intuitive result-based evaluation that allows successive query operations. Furthermore, the new JSONQuery module provides significant performance improvements, with 20-100x faster execution with the common filter operation on large arrays than the JSONPath module. JSONQuery generally supersets the functionality of JSONPath and provides syntax that matches and behaves like JavaScript where the syntax intersects for maximum ease of use.

(more…)

Dojo 1.2 Grid

Monday, July 14th, 2008

With the release of Dojo 1.2 right around the corner, there’s an updated grid widget available. It offers new features and performance improvements over the existing grid including better Dojo data integration, simplified layout structures, and the ability to enable editing much more easily.

(more…)

Touching and Gesturing on the iPhone

Thursday, July 10th, 2008

Everyone who owns an iPhone (or who has been holding out for an iPhone 3G) is bound to be excited about a lot of the new things the device can finally do, particularly the introduction of third-party applications. But those of us in the web development community have been itching for something further still: good web applications on the iPhone. This means we need a suitable replacement for mouse events. And boy did we get them! Though at first the APIs seem a little sketchy, once you’ve learned them you should be able to do amazing things in your application.

(more…)