Wiki source code of WebObjects with Scala
Version 247.1 by Ravi Mendis on 2009/09/15 20:43
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21.1 | 1 | === What is Scala? === |
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195.1 | 2 | |
| 3 | Scala is a modern language not unlike Groovy. | ||
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209.1 | 4 | It is said to be more powerful (and faster) than Groovy or Rails which has been the reason for its adoption at sites like Twitter. |
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195.1 | 5 | |
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247.1 | 6 | Many of its features and paradigms favor multi-threaded and concurrent development which may not be unfamiliar to Objective-C developers: |
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195.1 | 7 | |
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247.1 | 8 | |= |= Objective-C |= Java |= Scala |
| 9 | |= Mutable/Immuable Datatypes |Collections //e.g: NSArray/NSMutableArray// | No | //All datatypes// | ||
| 10 | |= Closures | //Extension// | No | //Built-in// | ||
| 11 | |= Static variables | Yes | Yes | No | ||
| 12 | |= Static methods/functions | Yes | Yes | No | ||
| 13 | |= Concurrency | Grand Central Dispatch (//Extension//) | //Threads// | Actors | ||
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195.1 | 14 | |
| 15 | Other notable features include: | ||
| 16 | |||
| 17 | |= |= Objective-C |= Java |= Scala | ||
| 18 | |= Parametered methods | Yes //e.g: addObject: to~:// | No | Yes //e.g: add(object= ,to=)// | ||
| 19 | |= Class composition | Categories | Interfaces | Traits | ||
| 20 | |||
| 21 | A fuller description of Scala can be found [[here>>http://en.wikipedia.org/wiki/Scala_(programming_language)]]. | ||
| 22 | |||
| 23 | === Why Use Scala? === | ||
| 24 | |||
| 25 | With Web 2.0, building concurrent WebObjects applications is a must. | ||
| 26 | Developing and maintaining a concurrent or multi-threaded WebObjects application can be challenging. | ||
| 27 | |||
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247.1 | 28 | Scala offers concurrency built into the language and is inherently thread-safe. |
| 29 | So it may offer new solutions to allowing concurrency in WebObjects. | ||
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195.1 | 30 | |
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247.1 | 31 | === Can WebObjects be Programmed With Scala? === |
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195.1 | 32 | |
| 33 | Yes. It is very simple. | ||
| 34 | Scala compiles to java bytecode. Hence using it with WebObjects is fairly straightforward. | ||
| 35 | |||
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247.1 | 36 | == How to Develop WebObjects With Scala == |
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195.1 | 37 | |
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231.1 | 38 | 1. [[Install the Scala eclipse IDE>>http://www.scala-lang.org/node/94]] |
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247.1 | 39 | 1. Add Scala support to your project |
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231.1 | 40 | 11. Right-click your project in the WO Explorer |
| 41 | 11. In the context menu select Scala -> Add Scala Nature | ||
| 42 | 1. Convert or use ##.scala## instead of ##.java## source | ||
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195.1 | 43 | |
| 44 | {{note title="Note"}} | ||
| 45 | |||
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247.1 | 46 | This is for Eclipse/WOLips developers |
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195.1 | 47 | |
| 48 | {{/note}} | ||
| 49 | |||
| 50 | == WO Scala Example == | ||
| 51 | |||
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205.1 | 52 | The following is a mixed Java/Scala version of the WO Movies D2W app. |
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195.1 | 53 | All the EO logic and WO components are in Scala. |
| 54 | Only the Application class is Java. | ||
| 55 | |||
| 56 | {{attachments patterns=".*zip"}}{{/attachments}} | ||
| 57 | |||
| 58 | === Setup === | ||
| 59 | |||
| 60 | 1. Install and run the OpenBase OBMovies database. | ||
| 61 | 1. Right-click on Application.java and run as a WOApplication (as usual). | ||
| 62 | |||
| 63 | ==== EO Templates ==== | ||
| 64 | |||
| 65 | See: [[Scala templates>>http://wiki.objectstyle.org/confluence/display/WOL/EOGenerator+Templates+and+Additions]] |