JarCastingepsilon-runtime
Eclipse Epsilon Runtime for Maven and OSGi. There are builders and helper classes, URI handlers that can help the usage of Epsilon out of Eclipse ecosystem.
What is Epsilon?
Epsilon is a family of languages and tools for code generation, model-to-model transformation, model validation, comparison, migration and refactoring that work out of the box with EMF, UML, Simulink, XML and other types of models.
The currently supported epsilon language dialects are: - EOL (Epsilon Object Language) - ETL (Epsilon Transformation Language) - EVL (Epsilon Validation Language) - EGL (Epsilon Generation Language) - EGX (Epsilon Generation XML(?)) - EML (Epsilon Merging Language) - ECL (Epsilon Comparison Language)
To understand the epsilon stack recommended to read the free epsilon book: https://www.eclipse.org/epsilon/doc/book/
Example
This example there is a model definition which can define a simple class structure with attributes and references. That models can be transformed to Liquibase (https://www.liquibase.org/) scripts. Liquibase XML format used which is defined with an XSD file, which techcally the meta model of an XML file. The original XSD file was modified (https://github.com/BlackBeltTechnology/epsilon-runtime/blob/develop/epsilon-runtime-execution/src/test/resources/liquibase.xsd) to be compatible with Ecore metamodel structure, so the output of transformation will be an XML file which is a Liquibase XML itself.
1. Define a meta-model. The meta-model contains the definition of our structure:
<?xml version="1.0" encoding="UTF-8"?>
<ecore:EPackage xmi:version="2.0" xmlns:xmi="http://www.omg.org/XMI" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:ecore="http://www.eclipse.org/emf/2002/Ecore" name="data" nsURI="http://www.blackbelt.hu/epsilon-runtime/test" nsPrefix="data">
<eClassifiers xsi:type="ecore:EClass" name="DataModel">
<eStructuralFeatures xsi:type="ecore:EAttribute" name="name" eType="ecore:EDataType http://www.eclipse.org/emf/2002/Ecore#//EString"/>
<eStructuralFeatures xsi:type="ecore:EReference" name="entity" upperBound="-1"
eType="#//Entity" containment="true"/>
</eClassifiers>
<eClassifiers xsi:type="ecore:EClass" name="Entity">
<eStructuralFeatures xsi:type="ecore:EAttribute" name="name" eType="ecore:EDataType http://www.eclipse.org/emf/2002/Ecore#//EString"/>
<eStructuralFeatures xsi:type="ecore:EReference" name="attribute" lowerBound="1"
upperBound="-1" eType="#//Attribute" containment="true"/>
<eStructuralFeatures xsi:type="ecore:EReference" name="reference" upperBound="-1"
eType="#//EntityReference" containment="true"/>
</eClassifiers>
<eClassifiers xsi:type="ecore:EClass" name="Attribute">
<eStructuralFeatures xsi:type="ecore:EAttribute" name="name" eType="ecore:EDataType http://www.eclipse.org/emf/2002/Ecore#//EString"/>
<eStructuralFeatures xsi:type="ecore:EAttribute" name="type" eType="ecore:EDataType http://www.eclipse.org/emf/2002/Ecore#//EString"/>
</eClassifiers>
<eClassifiers xsi:type="ecore:EClass" name="EntityReference">
<eStructuralFeatures xsi:type="ecore:EAttribute" name="name" eType="ecore:EDataType http://www.eclipse.org/emf/2002/Ecore#//EString"/>
<eStructuralFeatures xsi:type="ecore:EAttribute" name="toMany" eType="ecore:EDataType http://www.eclipse.org/emf/2002/Ecore#//EBoolean"/>
<eStructuralFeatures xsi:type="ecore:EReference" name="target" lowerBound="1"
eType="#//Entity"/>
</eClassifiers>
</ecore:EPackage>
|
Note
|
In EMF (Emfatic fomat) - You can convert between .ecore and .emf within eclipse. The epsilon-runtime will support emfatic format directly soon. |
@namespace(uri="http://www.blackbelt.hu/epsilon-runtime/test", prefix="data")
package data;
class DataModel {
attr String name;
val Entity[*] entity;
}
class Entity { // (1)
attr String name;
val Attribute[+] attribute;
val EntityReference[*] reference;
}
class Attribute { // (2)
attr String name;
attr String type;
}
class EntityReference { // (3)
attr String name;
attr boolean toMany;
ref Entity[1] target;
}-
Entity - Represents a class
-
Attribute - Represents an attribute of class
-
Reference - Represents a reference to a class
2. Define the model based on meta-model
<?xml version="1.0" encoding="ASCII"?>
<data:DataModel xmi:version="2.0" xmlns:xmi="http://www.omg.org/XMI" xmlns:data="http://www.blackbelt.hu/epsilon-runtime/test" xmi:id="_CeiO8EAJEemOdvXw1zCXyw">
<entity xmi:id="_Ds1OEEAJEemOdvXw1zCXyw" name="Test1">
<attribute xmi:id="_FB4VcEAJEemOdvXw1zCXyw" name="attr1" type="String"/>
</entity>
<entity xmi:id="_H8fscEAJEemOdvXw1zCXyw" name="Test2">
<attribute xmi:id="_Ja6yQEAJEemOdvXw1zCXyw" name="attr2" type="String"/>
<reference xmi:id="_LwhXsEAJEemOdvXw1zCXyw" name="test1" target="_Ds1OEEAJEemOdvXw1zCXyw"/>
</entity>
</data:DataModel>
|
Note
|
In HUTN (Emfatic fomat) - You can convert between .model and .hutn within eclipse. The epsilon-runtime will support hutn format directly soon. |
@Spec {
metamodel "http://www.blackbelt.hu/epsilon-runtime/test" {
nsUri: "http://www.blackbelt.hu/epsilon-runtime/test"
}
}
package {
DataModel "DataModel1" {
entity:
Entity "Test1" {
name: "Test1"
attribute:
Attribute "attr1" {
name: "attr1"
type: "String"
}
Entity "Test2" {
name: "Test2"
attribute:
Attribute "attr2" {
name: "attr2"
type: "String"
}
reference:
EntityReference "test1" {
name: "test1"
target: Entity "Test1"
}
}
}
}3. Define the transformation rules
The rules can be defined in ETL language (Epsilon Transformation Language).
rule DataModelToChangeLog
transform s : TEST1!DataModel
to t : LIQUIBASE!databaseChangeLog {
}
rule DataModelToChangeSet
transform s : TEST1!DataModel
to t : LIQUIBASE!ChangeSet {
t.id = s.name;
t.author = "test1toliquibase";
s.equivalent("DataModelToChangeLog").changeSet.add(t);
}
rule EntityToCreateTable
transform s : TEST1!Entity
to t : LIQUIBASE!CreateTable {
t.tableName = s.name;
TEST1!DataModel.all.selectOne(e | e.entity.contains(s)).equivalent("DataModelToChangeSet").createTable.add(t);
}
rule EntityToIdColumn
transform s : TEST1!Entity
to t : LIQUIBASE!Column {
t.name = "ID";
t.type = "Identifier";
s.equivalent("EntityToCreateTable").column.add(t);
}
rule EntityToPrimaryKey
transform s : TEST1!Entity
to t : LIQUIBASE!AddPrimaryKey {
t.tableName = s.name;
t.columnNames = "ID";
TEST1!DataModel.all.selectOne(d | d.entity.contains(s)).equivalent("DataModelToChangeSet").addPrimaryKey.add(t);
}
rule AttributeToColumn
transform s : TEST1!Attribute
to t : LIQUIBASE!Column {
t.name = s.name;
t.type = s.type;
TEST1!Entity.all.selectOne(e | e.attribute.contains(s)).equivalent("EntityToCreateTable").column.add(t);
}
rule EntityReferenceToColumn
transform s : TEST1!EntityReference
to t : LIQUIBASE!Column {
t.name = "ID_" + s.name;
t.type = "Identifier";
TEST1!Entity.all.selectOne(e | e.reference.contains(s)).equivalent("EntityToCreateTable").column.add(t);
}
rule EntityReferenceToAddForeignKeyConstraint
transform s : TEST1!EntityReference
to t : LIQUIBASE!AddForeignKeyConstraint {
var entity : TEST1!Entity = TEST1!Entity.all.selectOne(e | e.reference.contains(s));
t.constraintName = "FK_" + entity.name + "_" + s.`target`.name;
t.baseTableName = entity.name;
t.baseColumnNames = "ID_" + s.`target`.name;
t.referencedColumnNames = "ID";
t.referencedTableName = s.`target`.name;
TEST1!DataModel.all.selectOne(e | e.entity.contains(entity)).equivalent("DataModelToChangeSet").addForeignKeyConstraint.add(t);
}4. Run the transformation
// Preparing URI handler
uriHandler = new NioFilesystemnRelativePathURIHandlerImpl("urn", FileSystems.getDefault(),
new File(targetDir(), "test-classes").getAbsolutePath());
// Setup resourcehandler used to load metamodels
executionResourceSet = new CachedResourceSet();
executionResourceSet.getURIConverter().getURIHandlers().add(0, uriHandler);
// Executrion context
ExecutionContext executionContext = executionContextBuilder()
.log(slf4jLogger)
.resourceSet(executionResourceSet)
.metaModels(ImmutableList.of(
"urn:epsilon-runtime-test.ecore"))
.modelContexts(ImmutableList.of(
emfModelContextBuilder()
.log(slf4jLogger)
.name("TEST1")
.emf("urn:epsilon-runtime-test1.model")
.build(),
xmlModelContextBuilder()
.log(slf4jLogger)
.name("LIQUIBASE")
// TODO: XSDEcoreBuilder creating separate ResourceSet, so URIHandlers are not
// working. Have to find a way to inject
// .xsd("urn:liquibase.xsd")
.xsd(new File(targetDir(), "test-classes/liquibase.xsd").getAbsolutePath())
.xml("urn:epsilon-transformedliquibase.xml")
.readOnLoad(false)
.storeOnDisposal(true)
.build()))
.sourceDirectory(scriptDir())
.build();
// run the loading
executionContext.load();
// Transformation script
executionContext.executeProgram(
etlExecutionContextBuilder()
.source("transformTest1ToLiquibase.etl")
.build());
executionContext.commit();
executionContext.close();
The output liquibase model is:
<?xml version="1.0" encoding="UTF-8"?>
<databaseChangeLog xmlns="http://www.liquibase.org/xml/ns/dbchangelog">
<changeSet author="test1toliquibase">
<createTable tableName="Test1">
<column name="ID" type="Identifier"/>
<column name="attr1" type="String"/>
</createTable>
<createTable tableName="Test2">
<column name="ID" type="Identifier"/>
<column name="attr2" type="String"/>
<column name="ID_test1" type="Identifier"/>
</createTable>
<addForeignKeyConstraint baseColumnNames="ID_Test1" baseTableName="Test2" constraintName="FK_Test2_Test1"
referencedColumnNames="ID" referencedTableName="Test1"/>
<addPrimaryKey columnNames="ID" tableName="Test1"/>
<addPrimaryKey columnNames="ID" tableName="Test2"/>
</changeSet>
</databaseChangeLog>
