Changes for page WebObjects with Scala

Summary

• Page properties (1 modified, 0 added, 0 removed)

Details

Page properties

Content

...	...	@@ -1,18 +1,15 @@
1	1	=== What is Scala? ===
2	2
3		-[[Scala>>http://en.wikipedia.org/wiki/Scala_(programming_language)]] is a language for concurrent computing.
4		-In this day and age of multi-core processors, concurrent computing can't be ignored.
	3	+Scala is a modern language not unlike Groovy.
	4	+It is said to be more powerful (and faster) than Groovy or Ruby which has been the reason for its adoption at sites like Twitter.
5	5
6		-Many of Scala's features have been designed with concurrency in mind.
7		-Some of these may not be unfamiliar to Objective-C or WebObjects developers.
	6	+Many of its features and paradigms favor multi-threading and concurrency. Some of these may not be unfamiliar to Objective-C and WebObjects developers. Here's a summary:
8	8
9		-Here's a quick summary:
10		-
11	11	|= |= Objective-C |= Java |= Scala
12	12	|= Mutable/Immuable Datatypes | Collections //e.g: NSArray/NSMutableArray// | No | Yes
13	13	|= Closures | Blocks (//Extension//) | No | Anonymous Functions
14	14	|= Static variables | Yes | Yes | No
15		-|= Static methods or functions| Yes | Yes | No
	12	+|= Static methods/functions | Yes | Yes | No
16	16	|= Concurrency | [[Grand Central Dispatch>>http://en.wikipedia.org/wiki/Grand_Central_Dispatch]] (//Extension//)| //Threads// |[[Actors>>http://en.wikipedia.org/wiki/Actor_model]]
17	17	|= |= Weakly Typed |=--Strongly Typed--|= Strongly Typed
18	18
...	...	@@ -22,13 +22,18 @@
22	22	|= Parametered methods | Yes //e.g: addObject: to~:// | No | Yes //e.g: add(object= ,to=)//
23	23	|= Class composition | Categories | Interfaces | Traits
24	24
	22	+A fuller description of Scala can be found [[here>>http://en.wikipedia.org/wiki/Scala_(programming_language)]].
	23	+
25	25	=== Why Use Scala? ===
26	26
27		-Scala is inherently thread-safe.
28		-It has concurrency that is effectively built-in to the language.
	26	+With Web 2.0, building concurrent WebObjects applications is a must.
	27	+Developing and maintaining a concurrent or multi-threaded WebObjects application can be challenging.
29	29
30		-So for WebObjects developers, Scala offers itself as a powerful, safe and easy-to-use solution for [[concurrent applications>>Building Concurrent Applications with WebObjects and Scala]]. (In other words, Scala Actors can be used for problems that would have normally required threads).
	29	+Scala offers concurrency that is (effectively) built-in to the language and is inherently thread-safe.
	30	+In other words, developing Ajax (i.e asynchronous communication) with WO will require concurrent request handling and thread-safe code, for which Scala is a better choice than Java.
31	31
	32	+In addition it may offer new solutions for concurrency in WebObjects and EOF.
	33	+
32	32	=== Can WebObjects be Programmed In Scala? ===
33	33
34	34	Yes. It is very simple.
...	...	@@ -49,7 +49,7 @@
49	49
50	50	Java:
51	51
52		-{{code value="java"}}
	54	+{{code}}
53	53
54	54	public class _Talent extends EOGenericRecord {
55	55	public static final String ENTITY_NAME = "Talent";
...	...	@@ -71,7 +71,7 @@
71	71
72	72	In Java:
73	73
74		-{{code value="java"}}
	76	+{{code}}
75	75
76	76	import com.webobjects.eocontrol.EOGenericRecord;
77	77	import com.webobjects.eocontrol.EORelationshipManipulation;
...	...	@@ -94,7 +94,7 @@
94	94
95	95	In Java:
96	96
97		-{{code value="java"}}
	99	+{{code}}
98	98
99	99	public class MenuHeader extends WOComponent {
100	100
...	...	@@ -115,11 +115,11 @@
115	115	==== Simplified Exception Handling ====
116	116
117	117	Scala doesn't force you to catch exceptions unlike in Java.
118		-In addition, the syntax employs Scala's very powerful **pattern matching** to handle exceptions.
	120	+In addition, the syntax employs Scala's very powerful pattern matching to handle different exceptions.
119	119
120	120	In Java:
121	121
122		-{{code value="java"}}
	124	+{{code}}
123	123
124	124	try {
125	125	EditPageInterface epi = D2W.factory().editPageForNewObjectWithEntityNamed(_manipulatedEntityName, session());
...	...	@@ -153,7 +153,7 @@
153	153
154	154	{{/code}}
155	155
156		-==== Scala Annotations vs. Generated Accessors ====
	158	+==== Scala Annotations vs. Generic Accessors ====
157	157
158	158	An example of accessing variables in WebObjects with the following languages:
159	159
...	...	@@ -169,8 +169,6 @@
169	169
170	170	{{code}}
171	171
172		-import scala.reflect.BeanProperty
173		-
174	174	@BeanProperty var username = new String()
175	175	@BeanProperty var password = new String()
176	176	@BeanProperty var isAssistantCheckboxVisible = false
...	...	@@ -179,7 +179,7 @@
179	179
180	180	== How to Use Scala Collections with EOF ==
181	181
182		-One of the benefits of Scala is its very powerful, concurrency-ready collection classes - primarily ##List##, ##Map## and ##Set##.
	182	+One of the benefits of Scala is its very powerful, concurrency-ready collection classes - primarily ##List##, ##Map##, ##Seq## and ##Set##.
183	183	Employing these instead of ##NSArray## and ##NSDictionary## in WebObjects/EOF may be challenging.
184	184
185	185	But one may modify the EO templates to produce API such as:
...	...	@@ -233,7 +233,7 @@
233	233
234	234	== How to Build & Deploy a WebObjects Scala Project with Ant ==
235	235
236		-1. [[Download>>http://www.scala-lang.org/downloads]] and install Scala
237		-1. Set ##scala.home## (the location Scala has been installed onto) in the project ##build.properties## file
238		-1. [[Add the scalac task and properties>>Configuring Ant to Build Scala with WebObjects]] to the ant build.xml file
239		-1. Run from the project directory: ##sudo ant clean install##
	236	+1. Download an install Scala
	237	+1. The ##scala.home## (the location Scala has been installed onto) to the project ##build.properties## file
	238	+1. Add the ##scalac## tasks to the ant build.xml file
	239	+1. Customise the app classpath file. i.e either ##MacOSClasspath.txt## or ##UNIXClasspath.txt##. You will need to add an entry for ##scala-library.jar##