Migration Generator

Closes gh-47

Author: rainboyan

build.gradle

@@ -55,6 +55,7 @@ dependencies {
     api "org.hibernate:hibernate-core-jakarta:$HibernateCoreVersion"
 
     compileOnly "org.graceframework:grace-boot"
+    compileOnly "org.graceframework:grace-cli"
     compileOnly 'jakarta.servlet:jakarta.servlet-api:6.0.0'
     implementation "org.graceframework:grace-datastore-gorm:$gormVersion"
     compileOnly "org.graceframework.plugins:hibernate:$hibernatePluginVersion"

src/main/groovy/org/grails/plugins/databasemigration/generator/MigrationGenerator.groovy

@@ -0,0 +1,63 @@
+/*
+ * Copyright 2022-2025 the original author or authors.
+ *
+ * Licensed 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
+ *
+ *      https://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.
+ */
+package org.grails.plugins.databasemigration.generator
+
+import java.time.ZonedDateTime
+import java.time.ZoneId
+import java.time.format.DateTimeFormatter
+
+import groovy.transform.CompileStatic
+
+import grails.cli.generator.AbstractGenerator
+
+/**
+ * @author Michael Yan
+ * @since 6.3.0
+ */
+@CompileStatic
+class MigrationGenerator extends AbstractGenerator {
+
+    @Override
+    boolean generate() {
+        String[] args = commandLine.remainingArgs.toArray(new String[0])
+        if (args.size() < 2) {
+            return
+        }
+
+        boolean overwrite = commandLine.hasOption('force') || commandLine.hasOption('f')
+
+        ZonedDateTime now = ZonedDateTime.now(ZoneId.of('UTC'))
+        String migrationNumber = now.format(DateTimeFormatter.ofPattern('yyyyMMddHHmmss'))
+        String migrationName = args[1].uncapitalize()
+        String migrationFileName = [migrationNumber, migrationName].join('_') + '.groovy'
+
+        File changelogFile = new File(baseDir, 'db/migrations/changelog.groovy')
+        Map<String, Object> model = new HashMap<>()
+        model.put('id', System.currentTimeMillis().toString())
+
+        String migrationFile = 'db/migrations/' + migrationFileName
+        createFile('Migration.groovy.tpl', migrationFile, model, overwrite)
+
+        if (changelogFile.exists()) {
+            String content = changelogFile.text
+            changelogFile.text = content.substring(0, content.length() - 3) +
+                    "\n    include file: '${migrationFileName}'\n}\n"
+        }
+
+        true
+    }
+
+}

src/main/resources/META-INF/services/grails.cli.generator.Generator

@@ -0,0 +1 @@
+org.grails.plugins.databasemigration.generator.MigrationGenerator

src/main/resources/META-INF/templates/generators/migration/Migration.groovy.tpl

@@ -0,0 +1,7 @@
+databaseChangeLog = {
+
+    changeSet(author: "dbm", id: "$id-1") {
+
+    }
+
+}