Our hacky workaround of Grails' lacking snapshot dependency mechanism

_Events.groovy

/**
 * Libify version 1.0
 *
 * Copyright (C) 2012 Viaboxx Systems GmbH
 *
 * This is a copy of our base _Events.groovy script that serves in all our Grails plugins/projects.
 *
 * It goes into the "scripts" folder of a Grails project.
 *
 * NOTE: It requires a maven-ant-tasks-2.1.3.jar in your project, in a folder called "build-lib".
 *
 * Its main purpose is to work around Grails" lacking handling of snapshot dependencies.
 *
 * See http://www.viaboxxsystems.de/blog for more thoughts about it.
 *

 */

import groovy.xml.NamespaceBuilder

/**
 * Hook into grails clean
 */
eventCleanStart = {
    libifyClean()
}

/**
 * Hook into trigger libify
 */
eventResolveDependenciesEnd = {
    libify()
}

private libify() {
    File libifyDependenciesFile = new File("libify-dependencies.groovy")

    if (libifyDependenciesFile.exists()) {
        ant.echo "[Libify] Found libify definition in $libifyDependenciesFile"
        def deps = new GroovyShell().evaluate(libifyDependenciesFile)
        libifyDependencies(deps)
    }
    else println "No libify-dependencies.groovy found, so no deps will be added."
}

/**
 * Empty the libify directories
 * @return
 */
private libifyClean() {
    ant.echo "[Libify WARN] eventCleanStart was invoked, (deleting dir "target/libify-temp*")"
    ant.delete(includeemptydirs: true, failonerror: "false") {
        fileset(dir: "target", includes: "**/libify-temp*/**")
    }
}

def libifyDependencies(dependencies) {
    // Configure maven ant tasks:
    ant.path(id: "maven-ant-tasks.classpath", path: "build-lib/maven-ant-tasks-2.1.3.jar")
    ant.typedef(resource: "org/apache/maven/artifact/ant/antlib.xml",
            uri: "antlib:org.apache.maven.artifact.ant",
            classpathref: "maven-ant-tasks.classpath")
    def mvn = NamespaceBuilder.newInstance(ant, "antlib:org.apache.maven.artifact.ant")

    // Download dependencies into temp folder:
    def libifyTempDir = "target/libify-temp"
    ant.echo "[Libify] Copying maven dependencies into $libifyTempDir"

    mvn.dependencies(filesetId: "artifacts", versionsId: "dependency.versions") { dependencies.each { dependency(it) } }
    // Print the artifacts for debugging:
    // ant.fileScanner { fileset(refid: "artifacts") }.each { println it }

    ant.copy(todir: libifyTempDir, overwrite: true) {
        fileset(refid: "artifacts")
        mapper(classpathref: "maven-ant-tasks.classpath", classname: "org.apache.maven.artifact.ant.VersionMapper", from: "${dependency.versions}", to: "flatten")
    }

    ant.echo "[Libify] Adding direct dependencies to classpath: " + libifyDeps

    // Add dependencies to the classpath:
    dependencies.each {
        if (it.scope != "runtime" && it.scope != "provided") {
            def jar = new File(libifyTempDir, it.artifactId + "." + it.type)
            rootLoader.addURL(jar.toURL())
        }
    }

    // Create a space-separated string of file names to be included in the WAR:WEB-INF/lib:
    def includeDeps = ""
    dependencies.each {
        includeDeps += it.artifactId + "." + it.type + " "
    }

    // Reconfigure what goes into the WAR file:
    buildConfig.grails.war.dependencies = {   antBuilder ->
        // add libified files to war/WEB-INF/lib
        fileset(dir: libifyTempDir, includes: includeDeps)
        fileset(dir: "${basedir}/lib") {
            include(name: "*.jar")
        }
        grailsSettings.runtimeDependencies?.each { File f ->
            fileset(dir: f.parent, includes: f.name)
        }
    }
}