5. C code compiles as Objective-C code

7. Implementing methods

8. Instantiating classes and objects

9. Invoking class and object methods

10. Protocols, categories, selectors, forwarding

12. Is is a simple extension of C

14. It can be as high-level and flexible as Smalltalk if you use the object-oriented extensions

16. Powerful “ Foundation ” class library

18. High-level language. Organize your server code using high-level, object-orientated design patterns.

19. Powerful Foundation library (GNUstep-base). The API originates from OpenStep and the implementation has been polished for 13+ years.

21. Basic data classes : NSString, NSNumber, NSData, NSNull

22. Collection classes : NSArray, NSDictionary, NSSet

23. Execution control classes : NSRunLoop, NSTimer, NSThread, NSLock

24. I/O classes : NSTask, NSFileHandle

25. Notification classes: NSNotification, NSDistributedNotification

26. Serialization classes: NSArchiver, NSCoder

27. Resource management classes: NSBundle, NSUserDefaults

28. Distributed Objects Classes: NSConnection, NSPort

29. And many more... Application Foundation Kit Application Kit Operating System OS Graphical System Objective-C Runtime

30. GNUstep-base Application GNUstep Base GNUstep GUI Operating System (Any!) Graphical System (Any!) GNU Objective-C Runtime GNUstep Back

34. Provides “core” non-graphical Objective-C classes

38. Install it from your GNU/Linux distribution

39. Typical Quick Installation (Ubuntu) apt-get libgnustep-base-dev

40. Typical Manual Installation (RedHat) yum install gcc-objc libxml-devel openssl-devel wget ftp://sourceware.org/pub/libffi/libffi-3.0.1.tar.gz tar xfvz libffi-3.0.1.tar.gz cd libffi-3.0.1 ./configure make su -c 'make install' <edit /etc/ld.so.conf adding /usr/local/lib, then run ldconfig as root> wget ftp://ftp.gnustep.org/pub/gnustep/core/gnustep-make-2.0.8.tar.gz tar xfvz gnustep-make-2.0.8.tar.gz cd gnustep-make-2.0.8.tar.gz ./configure make su -c 'make install' . /usr/GNUstep/System/Library/Makefiles/GNUstep.sh wget ftp://ftp.gnustep.org/pub/gnustep/core/gnustep-base-1.18.0.tar.gz tar xfvz gnustep-base-1.18.0.tar.gz cd gnustep-base-1.18.0 ./configure –enable-openssl make su -c 'make install'

47. When you create a NSString or NSArray you actually get an instance of a subclass optimized to perform best in your situation

48. Method dispatch is dynamic, so that works

50. NSString is for constant strings that never change

51. NSMutableString is for strings that might change

52. Allows a lot of optimizations inside the library

54. Full Unicode support

55. Class cluster implementation means ASCII strings are still extremely fast

60. Description = “GNUstep GUI Builder Application”;

63. Event-based model

64. NSFileHandle

66. NSLock

68. Objects can “observe” a notification and specify which method

69. they want invoked when that notification is posted

70. Anything can “post” a notification

73. A delegate allows you to extend a class without subclassing it

74. Subclassing can be heavy, and not that flexible

75. Delegates are more flexible – you can delegate part of the code to

76. an object of any class

77. -setDelegate: (NSObject *)delegate;

78. -delegate;

80. High-level

81. You can expose objects in one process to other processes

82. Other processes can then contact the object and invoke methods

83. of the objects, as if they were local objects

84. Very natural to use

85. Excellent for building networks of processes that work cooperatively

86. See http://www.gnustep.it/nicola/Tutorials/ for a tutorial on Distributed Objects.

89. Apple Cocoa non-GUI frameworks can sometime be used

93. Not so interesting if you're not

96. Advanced transaction support

97. Query caching

98. Update Batching

100. Object-to-relationship mapping

101. Extensive use of KVC

103. DBModeler (GUI program)

105. You have to write your SQL code

106. Performance-oriented

108. You works with models and objects – you do not need to write SQL

109. Can be a bit hard to get into, but people love it once they get used to it

110. Excellent for large and properly structured OO projects

111. Performance is generally good

113. Appropriate to develop efficient APIs for your system

114. Could be used for web pages but that is not the focus

115. Provides a full web server

116. Usually used with Apache in front as a reverse-proxy

118. And allows you to use Java libraries or objects from Objective-C

119. Objects and classes in Objective-C are mapped to objects and

121. Problems can be hard to debug

122. Limited support for cross-language subclassing

123. Not easy to port to other platforms

125. A complete “Web application server” environment

126. Apple WebObjects compatible app server extended with Zope concepts

127. XML processing (SAX2, DOM, XML-RPC)

128. MIME/IMAP4 processing

129. LDAP connectivity

130. RDBMS connectivity

132. Questions ?