Dsl로 만나는 groovy
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The document discusses Domain Specific Languages (DSLs) and how Groovy is well-suited for creating DSLs. It provides examples of DSLs like XML, HTML, and SQL. It then explains how Groovy features like dynamic typing, closures, meta-programming capabilities via metaclasses, and chaining methods allow it to easily define and implement DSLs. Specific Groovy DSL examples discussed include builders for XML/HTML, the GORM for object-relational mapping, and a Korean language DSL.
![Groovy Builder DSL - HTML
def writer = new StringWriter()
def html = new groovy.xml.MarkupBuilder(writer)
html.html {
head { title 'Constructed by MarkupBuilder' }
body {
h1 'What can I do with MarkupBuilder?'
form (action:'whatever') {
for (line in [
'Produce HTML',
'Produce XML',
'Have some fun'
]){
input(type:'checkbox',checked:'checked', id:line, '')
label(for:line, line)
br('')
}
}
}
}
println writer](https://image.slidesharecdn.com/dslgroovy-131013002037-phpapp01/85/Dsl-groovy-5-320.jpg)
![MOP Hooks – methodMissing
class GORM {
}
def dynamicMethods = [...] // an array of dynamic methods that use regex
def methodMissing(String name, args) {
def method = dynamicMethods.find { it.match(name) }
if(method) {
GORM.metaClass."$name" = { Object[] varArgs ->
method.invoke(delegate, name, varArgs)
}
return method.invoke(delegate,name, args)
}
else throw new MissingMethodException(name, delegate, args)
}
http://groovy.codehaus.org/Using+methodMissing+and+propertyMissing](https://image.slidesharecdn.com/dslgroovy-131013002037-phpapp01/85/Dsl-groovy-13-320.jpg)
Dsl로 만나는 groovy
- 2. DSL •DSLR? DSL? A domain-specific language (DSL) is a computer language specialized to a particular application domain. http://en.wikipedia.org/wiki/Domain-specific_language http://www.aladin.co.kr/shop/wproduct.aspx?ISBN=8991268994 •DSL <-> GPL(General Purpose Language) •DSL = Mini Languages •DSL Example => XML, HTML, CSS, SQL •Groovy로 해석되는 DSL – 각종 Builder, GORM, gradle, Grails
- 3. Groovy? • • • • Ruby? Dynamic Language? 다양한 빌더 Grails, gradle, GORM 등
- 4. Groovy Builder DSL – XML writer = new StringWriter() builder = new groovy.xml.MarkupBuilder(writer) builder.numbers { description 'Squares and factors of 10..15' for (i in 10..15) { number (value: i, square: i*i) { //#1 for ( j in 2..<i) { if (i % j == 0) { factor (value: j) //#2 } } } } } println writer http://groovyconsole.appspot.com/
- 5. Groovy Builder DSL - HTML def writer = new StringWriter() def html = new groovy.xml.MarkupBuilder(writer) html.html { head { title 'Constructed by MarkupBuilder' } body { h1 'What can I do with MarkupBuilder?' form (action:'whatever') { for (line in [ 'Produce HTML', 'Produce XML', 'Have some fun' ]){ input(type:'checkbox',checked:'checked', id:line, '') label(for:line, line) br('') } } } } println writer
- 6. GORM – DSL • ORM DSL – Mapping • Table, Column mapping • Relational mapping – ORM관련 설정 • • • • Cache 전략 Custom ID 전략 Composite Primary Keys Index 설정 – http://grails.org/doc/latest/guide/single.html#ormdsl • Query DSL – Basic Query • list, get, getAll – Dynamic Finders • findByXXX – – Book.findByTitle(„정글만리‟), findByTitleLike(„%정글‟) http://grails.org/doc/latest/ref/Domain%20Classes/findBy.html
- 7. Groovy로 만든 한글 DSL Object.metaClass.을 = Object.metaClass.를 = Object.metaClass.의 = { clos -> clos(delegate) } 먼저 = { it } 표시하라 = { println it } 제곱근 = { Math.sqrt(it) } 먼저 100 의 제곱근 을 표시하라 먼저(100).의(제곱근).을(표시하라) 출처: http://it.gilbird.com/textyle/8318
- 8. Groovy는 왜 DSL에 강한가? • Dynamic Language – Dynamic Type num = 10; str = “20” assert num instanceof Integer assert str instanceof String – Closure • Caller에게 양보하기 – MOP(Meta Class, Expando Class) • 요술상자, 아메바 – Groovy‟s chain method calls (GEP 3) • 괄호 빼기 먼저 100 의 제곱근 을 표시하라 먼저(100).의(제곱근).을(표시하라) • JVM 기반 – Groovy는 결국 Java Class로 컴파일 – 거의 95%이상 Java와 동일하게 코딩 가능 – Java와 Groovy의 혼용
- 9. Groovy MOP • MOP(Meta Object Protocol) – MetaObjectProtocol • http://en.wikipedia.org/wiki/Metaobject • MetaClass, ExpandoMetaClass http://mrhaki.blogspot.kr/2009/10/groovy-goodness-expando-as-dynamic-bean.html – 요술을 부리는 MOP Hooks • invokeMethod, methodMissing, get/setProperty, propertyMissing
- 10. Groovy MetaClass
- 11. MOP Hooks - invokeMethod import org.codehaus.groovy.runtime.StringBufferWriter import org.codehaus.groovy.runtime.InvokerHelper class Traceable implements GroovyInterceptable { Writer writer = new PrintWriter(System.out) private int indent = 0 Object invokeMethod(String name, Object args){ writer.write("n" + ' '*indent + "before method '$name'") writer.flush() indent++ def metaClass = InvokerHelper.getMetaClass(this) def result = metaClass.invokeMethod(this, name, args) indent-writer.write("n" + ' '*indent + "after method '$name'") writer.flush() return result } } class Whatever extends Traceable { int outer(){ return inner() } int inner(){ return 1 } } def log = new StringBuffer() def traceMe = new Whatever(writer: new StringBufferWriter(log)) assert 1 == traceMe.outer() println log
- 12. Method 실행 순서
- 13. MOP Hooks – methodMissing class GORM { } def dynamicMethods = [...] // an array of dynamic methods that use regex def methodMissing(String name, args) { def method = dynamicMethods.find { it.match(name) } if(method) { GORM.metaClass."$name" = { Object[] varArgs -> method.invoke(delegate, name, varArgs) } return method.invoke(delegate,name, args) } else throw new MissingMethodException(name, delegate, args) } http://groovy.codehaus.org/Using+methodMissing+and+propertyMissing
- 14. Groovy Closure def lineFile = new File(getClass().getResource("numbers.txt").getPath()) def sumValue = 0, multiflyValue = 1, concateValue = '' lineFile.eachLine { sumValue += Integer.parseInt(it) multiflyValue *= Integer.parseInt(it) concateValue += it } assert sumValue == 10 assert multiflyValue == 24 assert concateValue == '1234'
- 15. 한국어 DSL로 돌아와서 Object.metaClass.을 = Object.metaClass.를 = Object.metaClass.의 = { clos -> clos(delegate) } 먼저 = { it } 표시하라 = { println it } 제곱근 = { Math.sqrt(it) } 먼저 100 의 제곱근 을 표시하라 먼저(100).의(제곱근).을(표시하라) 100.제곱근 을 표시하라 출처: http://it.gilbird.com/textyle/8318
- 16. 관련 자료 • http://notes.3kbo.com/groovy-dsls • http://en.wikipedia.org/wiki/Domainspecific_language • DSL 번역본 • 프로그래밍 그루비 • 한국어 DSL • Groovy for Domain-Specific Languages • http://en.wikipedia.org/wiki/Metaobject • http://groovy.codehaus.org/api/overviewsummary.html • Groovy Grails 의 좋은 점 • ★ Groovy