Objective-J

src: i.ytimg.com

Objective-J is a programming language developed as part of the Cappuccino web development framework. Its syntax is nearly identical to the Objective-C syntax and it shares with JavaScript the same relationship that Objective-C has with the C programming language: that of being a strict, but small, superset; adding traditional inheritance and Smalltalk/Objective-C style dynamic dispatch. Pure JavaScript, being a prototype-based language, already has a notion of object orientation and inheritance, but Objective-J adds the use of class-based programming to JavaScript.

Programs written in Objective-J need to be preprocessed before being run by a web browser's JavaScript virtual machine. This step can occur in the web browser at runtime or by a compiler which translates Objective-J programs into pure JavaScript code. The Objective-J compiler is written in JavaScript; consequently, deploying Objective-J programs does not require a web browser plug-in. Objective-J can be compiled and run on Node.js.

Video Objective-J

Applications

The first widely known use of Objective-J was in the Cappuccino-based web application 280 Slides, which was developed by 280 North itself. Even though Objective-J can be used (and has been designed) independently from the Cappuccino framework, Objective-J has primarily been invented to support web development in Cappuccino.

Applications designed using the Cappuccino Framework

• Mockingbird
• PicEngine
• GithubIssues
• TimeTable
• Enstore (until October 2013, they rewrote it using Ember )
• Almost At
• Akshell - Online JavaScript Web-App IDE
• Archipel Project - Virtual machine orchestrator
• Spot Specific - Mobile App SDK and IDE

Maps Objective-J

Syntax

Objective-J is a superset of JavaScript, which means that any valid JavaScript code is also valid Objective-J code.

The following example shows the definition and implementation in Objective-J of a class named Address; this class extends the root object CPObject, which plays a role similar to the Objective-C's NSObject. This example differs from traditional Objective-C in that the root object reflects the underlying Cappuccino framework as opposed to Cocoa, Objective-J does not use pointers and, as such, type definitions do not contain asterisk characters. Instance variables are always defined in the @implementation.

As with Objective-C, class method definitions and instance method definitions start with '+' (plus) and '-' (dash), respectively.

src: ozov.biz

Memory management

Objective-C uses ARC (Automatic Reference Counting) for deallocating unused objects. In Objective-J, objects are automatically deallocated by JavaScript's Garbage Collector.

src: www.jinx.com

See also

• Cappuccino (application development framework)

src: ozov.biz

References

src: ozov.biz

External links

• Official website
• "Learning Objective-J". Cappuccino Web Framework. 

Source of the article : Wikipedia