Wt (pronounced "witty") is an open source widget-centric web application framework for the C++ programming language developed by Emweb. It has an API that resembles the C++ desktop application library Qt, also using a widget tree and event-driven signal/slot programming model.

The goal of the library is to benefit from the stateful component model used in desktop applications APIs, applied to web development, instead of the traditional model–view–controller (MVC) model. Rather than using MVC at the level of a page, MVC is pushed to the level of individual components.

While the library uses a desktop application development model, it does support web-specific features including clean URLs and browser history navigation support.

A unique feature of the library is its abstraction layer of the browser rendering model. The library uses Ajax for communicating with Ajax-capable browsers, while using plain HTML form post-backs for other user agents. Using a progressive bootstrap method, the user interface is initially rendered as plain HTML, and for Ajax-capable browsers, it is automatically upgraded to use Ajax for increased interactivity. In this way, it is the only server-side framework that implements progressive enhancement automatically, and the only Ajax framework with search engine optimization (SEO) qualities.

Because of the popularity of C/C++ in embedded system environments, the library is often used in such devices, and has been highly optimized for performance as a consequence.

Major features

See the feature list on the project homepage for a more detailed overview.

• Automatic graceful degradation and progressive enhancement
• Supports server-initiated events (comet (programming))
• A unified rendering API (SVG/HTML5 canvas/VML)
• Both client-side and server-side validation
• Various security features to avoid Cross-site scripting and CSRF vulnerabilities.
• Includes a compact, modern C++ ORM layer (Wt::Dbo)
• Uses WebSockets if available for communication between client and server, with fallbacks to Ajax or plain web pages

See also

Free software portal

• Comparison of web application frameworks
• JWt Java web toolkit (JWt homepage), a native Java version obtained using automated C++ to Java translation.

References

• Article in Dr Dobb's Journal, Feb 2008
• Introductory article at CodeGuru, Jun 2008

External links

• Wt project homepage