Importing external domain classes into Grails - grails

Question

I'm trying to create a sample project where domain classes are in an external normal groovy project and then used in a grails app (see https://github.com/ivanarrizabalaga/grails-domain-griffon):
book-svr
book-common
I'm also following the grails guide in order to get this (see http://grails.org/doc/latest/guide/hibernate.html) but the imported classes are not being recognized as domain classes.
The relevant parts:
External domain class:
package com.nortia.book
import grails.persistence.Entity
#Entity
class Book implements Serializable{
private static final long serialVersionUID = 1L;
String title
String author
static constraints = {
title blank:false
author blank:false
}
}
build.gradle:
....
dependencies {
// We use the latest groovy 2.x version for building this library
compile 'org.codehaus.groovy:groovy:2.1.7'
compile "org.grails:grails-datastore-gorm-hibernate4:3.0.0.RELEASE"
compile "org.grails:grails-spring:2.3.7"
....
In the grails app,
hibernate.cfg.xml:
<?xml version='1.0' encoding='UTF-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
'-//Hibernate/Hibernate Configuration DTD 3.0//EN'
'http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd'>
<hibernate-configuration>
<session-factory>
<mapping package='com.nortia.book' />
<mapping class='com.nortia.book.Book' />
</session-factory>
</hibernate-configuration>
BookController.groovy (I've tried an scaffolded and coded controller, and both failed):
...
class BookController{
static scaffold=Book
}
...
console.log (error):
ERROR ScaffoldingGrailsPlugin - Cannot generate controller logic for scaffolded class class com.nortia.book.Book. It is not a domain class!
Finally, suspicious log messages while initializing:
DEBUG cfg.Configuration - session-factory config [null] named package [com.nortia.book] for mapping
INFO cfg.Configuration - Mapping package com.nortia.book
WARN cfg.AnnotationBinder - Package not found or wo package-info.java: com.nortia.book
DEBUG cfg.Configuration - session-factory config [null] named class [com.nortia.book.Book] for mapping
INFO cfg.Configuration - Configured SessionFactory: null
So I'm wondering:
What's the missing piece?
According to the docs, looks like external 'domains' must be java classes but that's not a good option for my purpose.
I haven't try yet with a grails binary plugin instead of a groovy project, is it the way to go? (I need to use the domains in a griffon project that is why I opted this way first).

Answer 1

Finally solve it creating a 'sort of' a binary plugin manually.
Let's take a look step by step:
book-domain
Tree structure
src
main
groovy
demo
Book.groovy
resources
META-INF
grails-plugin.xml
build.gradle
Book.groovy
package demo
import grails.persistence.Entity
#Entity
class Book{
String title
static constraints = {
title blank: false
}
}
grails-plugin.xml
<plugin name='book-domain' version='1.0' grailsVersion='2.3 > *'>
<author>Ivan Arrizabalaga</author>
<title>External domains</title>
<description>An external domain plugin</description>
<documentation>http://grails.org/plugin/book-domain</documentation>
<type>demo.BookDomainGrailsPlugin</type>
<packaging>binary</packaging>
<resources>
<resource>demo.Book</resource>
</resources>
</plugin>
build.gradle
/*
* This build file was auto generated by running the Gradle 'init' task
* by 'arrizabalaga' at '5/26/14 12:34 PM' with Gradle 1.11
*
* This generated file contains a sample Groovy project to get you started.
* For more details take a look at the Groovy Quickstart chapter in the Gradle
* user guide available at http://gradle.org/docs/1.11/userguide/tutorial_groovy_projects.html
*/
// Apply the groovy plugin to add support for Groovy
apply plugin: 'groovy'
apply plugin: 'maven'
group = 'demo'
version = '1.0'
// In this section you declare where to find the dependencies of your project
repositories {
// Use 'maven central' for resolving your dependencies.
// You can declare any Maven/Ivy/file repository here.
mavenCentral()
mavenLocal()
}
// In this section you declare the dependencies for your production and test code
dependencies {
// We use the latest groovy 2.x version for building this library
compile 'org.codehaus.groovy:groovy-all:2.1.9'
//compile "org.grails:grails-datastore-gorm-hibernate4:3.1.0.RELEASE"
compile "org.grails:grails-datastore-gorm-hibernate:3.1.0.RELEASE"
compile "commons-lang:commons-lang:2.6"
// We use the awesome Spock testing and specification framework
testCompile 'org.spockframework:spock-core:0.7-groovy-2.0'
testCompile 'junit:junit:4.11'
}
task sourcesJar(type: Jar, dependsOn: classes) {
classifier = 'sources'
from sourceSets.main.allSource
}
task javadocJar(type: Jar, dependsOn: javadoc) {
classifier = 'javadoc'
from javadoc.destinationDir
}
artifacts {
archives sourcesJar
archives javadocJar
}
using it
Now the project can be built (gradle install to publish it into your local maven repo) and used (declaring the proper dependency) in any given project.
If the project that uses the jar is a Grails app it turns automatically the #Entity classes into real Domains.
Hope it helps.