Jump to content

LiveCode

From Wikipedia, the free encyclopedia
This is an old revision of this page, as edited by RunRevKev (talk | contribs) at 17:16, 17 February 2011 (Bibliography). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.
LiveCode
ParadigmObject-oriented
DeveloperRuntime Revolution, Ltd
First appeared1993 (1993)
OSiOS, Mac OS X, Mac OS 9, Microsoft Windows, Linux, Solaris
LicenseProprietary
Websitewww.runrev.com
Influenced by
HyperTalk

The LiveCode programming language (formerly the "Revolution" programming language) is a commercial Cross-platform rapid application development language inspired by Hypercard's programming language HyperTalk. It is developed and sold by Runtime Revolution Ltd., based in Edinburgh, Scotland. The language was first introduced in 2001 and has tens of thousands of users.

LiveCode runs on iOS, Android, Mac OS X, Windows 95 through Windows 7, and many variations of Unix, including Linux, Solaris, and BSD. It can be used for both desktop and server/CGI applications. The first version for iOS (iPhone and iPad) was released in December 2010. It is the most widely used Hypercard/HyperTalk clone, and the only one that runs on all major operating systems.

LiveCode allows developers to create applications that run in any environment, using a compile-free workflow. Developers can reuse the same code across multiple devices and platforms from a single code base. LiveCode uses a high level, English-like programming language that is dynamically typed. The sensible programming language and compile-free workflow allow for logical code that is self-documenting and easy for casual programmers to comprehend. For example:

 repeat ten times
   put "Hello world at" && the time & return after field 1
   wait two seconds
 end repeat

Will place ten lines of "Hello world at 9:00 AM" into the first field.

While its natural-language syntax appeals to beginners, the language contains advanced features including associative arrays, regular expressions, QuickTime multimedia, support for a variety of SQL databases, and TCP/IP libraries. The LiveCode engine supports a variety of graphics formats, anti-aliased vector graphics, embedded web browsers. Yet, accessing these higher-level functions is still quite easy.

For example, to load the contents of a web page into a variable takes one line of code:

put url "http://www.yahoo.com" into MyVariable

To upload a file via FTP is similar:

put url "binfile:picture.jpg" into url "ftp://john:passwd@ftp.example.net:2121/picture.jpg"

The 1900 built-in language terms and keywords may be extended by external libraries written in C and other lower level languages.

LiveCode project files are binary-compatible across platforms. They inherit each platform's unique look and feel and behaviors with no modification. For example, buttons, scrollbars, progress bars and menus behave correctly without any intervention on the part of the developer.

Compiling a standalone produces a single-file executable (minimum size ~1.5MB) for each platform targeted. There is no separate runtime necessary.

The Wikipedia article on Hypercard, being at root quite similar, contains a more detailed discussion about the basics of the development environment and scripting language. LiveCode is a much richer and far more powerful evolution of that original program, supporting multiple platforms, devices and many fundamental language extensions such as object-oriented behaviors.

See also

Bibliography