| /////////////////////////////////////////////////////////////// |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| /////////////////////////////////////////////////////////////// |
| |
| [[lang-scala, Scala Library]] |
| = Scala Support = |
| |
| [devstatus] |
| -------------- |
| source=libraries/lang-scala/dev-status.xml |
| -------------- |
| |
| The Scala Support Library allows Fragments and Composites to be written as Scala traits. |
| |
| include::../../build/docs/buildinfo/artifact.txt[] |
| |
| The Scala Support Library is a Generic mixin class that implements Composites by delegating to Scala traits. |
| |
| |
| == Composition == |
| |
| Example mixin declaration: |
| [snippet,scala] |
| ---- |
| source=libraries/lang-scala/src/test/scala/org/qi4j/sample/scala/HelloWorldMixin2.scala |
| tag=mixin |
| ---- |
| |
| Example composite declaration: |
| [snippet,scala] |
| ---- |
| source=libraries/lang-scala/src/test/scala/org/qi4j/sample/scala/HelloWorldComposite.scala |
| tag=composite |
| ---- |
| |
| Example typed concern: |
| [snippet,scala] |
| ---- |
| source=libraries/lang-scala/src/test/scala/org/qi4j/sample/scala/HelloThereConcern.scala |
| tag=typedconcern |
| ---- |
| |
| Example generic concern with filter: |
| [snippet,scala] |
| ---- |
| source=libraries/lang-scala/src/test/scala/org/qi4j/sample/scala/ExclamationGenericConcern.scala |
| tag=genericconcern |
| ---- |
| |
| And the assembly code. |
| Note that the `ScalaTraitMixin` must be added. |
| [snippet,java] |
| ---- |
| source=libraries/lang-scala/src/test/scala/org/qi4j/sample/scala/HelloWorldCompositeTest.java |
| tag=composite |
| ---- |
| |
| That pretty much covers the domain model part. |
| Usage from Java is transparent, since it looks just like interfaces and classes. |
| |
| |
| == Entity composites == |
| |
| The following example separate between command interface (suggestions to change), events (after the fact), and data, so they are in three separate traits below. |
| Only commands are called by client code. |
| |
| [snippet,scala] |
| ---- |
| source=libraries/lang-scala/src/test/scala/org/qi4j/sample/scala/TestEntity.scala |
| tag=entity |
| ---- |
| |
| The `self` operator thing solves the `@This` injection requirements, although it doesn't do private injections (i.e. the Entity *has* to extend Events and Data for it to work). |
| |
| Everything is statically typed. |
| |
| And the corresponding assembly code: |
| |
| [snippet,java] |
| ---- |
| source=libraries/lang-scala/src/test/scala/org/qi4j/sample/scala/HelloWorldCompositeTest.java |
| tag=entity |
| ---- |
| |
| |
| == Services composites == |
| |
| The following example is a pretty simple service written as a Scala trait: |
| |
| [snippet,scala] |
| ---- |
| source=libraries/lang-scala/src/test/scala/org/qi4j/sample/scala/TestService.scala |
| tag=service |
| ---- |
| |
| And the corresponding assembly code: |
| |
| [snippet,java] |
| ---- |
| source=libraries/lang-scala/src/test/scala/org/qi4j/sample/scala/HelloWorldCompositeTest.java |
| tag=service |
| ---- |