jgs CSE 564 Software Design Lecture 23: Model-Driven Development Dr. Javier Gonzalez-Sanchez [email protected] javiergs.engineering.asu.edu | javiergs.com PERALTA 230U Office Hours: By appointment 

jgs Frameworks vs Libraries 

jgs 564 00010100 Johnson (1997) § Component represent code reuse A framework is a reusable design represented by a set of components and the way they interact. A framework implement an architecture § Framework = Components + Design + Domain Specific Solution 

jgs 564 00010100 Framework vs Library § Inversion of Control: the framework determines the flow of control i.e., reuse of main § Model-View-Controller - a framework or an architectural pattern? 

jgs 564 00010100 Eric Gamma 

jgs Next Model-Driven Development 

jgs 564 00010100 Definition Model-driven software development (MDD) § Write and implement software quickly, effectively and at minimum cost. § The approach focuses on the construction of a software model. § The model (text or graphic) specifies how the software system should work before the code is generated. § The software is created automatically (translate the model to code) § Tested and then deployed. 

jgs 564 00010100 MDD Development Process http://www.theenterprisearchitect.eu/blog/2009/08/05/a-metaphor-for-model-driven-engineering/ 

jgs 564 00010100 MDD Development Process 

jgs 564 00010100 MDD Development Process 

jgs 564 00010100 MDD Development Process 

jgs 564 00010100 MDD Development Process 

jgs 0. The Tool: Eclipse Modeling Framework 

jgs 564 00010100 Eclipse § Eclipse is a universal platform for integrating development tools § Architecture based on plug-ins § SWT (Standard Widget Toolkit) is a generic graphics and GUI widget set § JFace is set of UI frameworks for common UI tasks § Workbench and Workspace are core – Editors, Views, and Perspectives 

jgs 564 00010100 Eclipse Modeling Framework 2. Model specification (it is stored as XMI but defined as text or diagram). A subset of UML class diagrams semantics 1. EMF provides tools and runtime environment. 3. Translate to Java Classes and Interfaces 

jgs 564 00010100 Download Eclipse Modeling Tools 

jgs 564 00010100 Eclipse Modeling Tools 

jgs 1. Define the Model 

jgs 564 00010100 Model UML Class Diagram Description 

jgs 564 00010100 Step 1 :: Project § Create an empty modeling project in your workspace File → New → Other… and choose Empty EMF Project § Click Next, enter a name for the project, e.g., org.eclipse.example.mymodel, and hit Finish 

jgs 564 00010100 Step 2 :: Model § Please right click the model folder in your new modeling project then New → Other… → Ecore Model, then click Next and give the ecore file the name myModel.ecore. § It will open in the default Ecore editor, which allows the definition of Ecore models in a tree-based view 

jgs 564 00010100 Step 2 :: Model :: Package § Give the package of your new model a name and an URI. This will be done in the properties view. The URI is used to identify the model later. Name the package myModel, Set the Ns Prefix to org.eclipse.example.myModel and the Ns URI to https://org/eclipse/example/myModel. 

jgs 564 00010100 Step 2 :: Model :: Classes and Attributes § Define model elements as children of the root package by right clicking on the myModel package and on the EClass respectively Add EClass as children, New Child → EClass Add EAttribute as children, New Child → EAttribute 

jgs 564 00010100 Step 2 :: Model :: Relationships § EReference between Course and Student, New Child → EReference EType of the reference to “Student” upper bound to “-1”, the equivalent of “many”. set the property Containment to “true” 

jgs 564 00010100 Step 2 :: Model :: Relationships § EReference between Student and Computer, New Child → EReference EType of the reference to “Computer” upper bound to “1” (default) set the property Containment to “false” § Save all 

jgs 2. Code Generation 

jgs 564 00010100 Eclipse Modeling Framework 

jgs 564 00010100 Generator Model § Create a generator model. This allows to configure properties for the code generation that are not part of the model itself. § Generate a maximum of four different plugins for a defined model: 1. Model plugin contains all entities, packages and factories to create instances of the model. 2. Edit plugin contains providers to display a model in a UI. For example, the providers offer a label for every model element, which can be used to display an entity showing an icon and a name. 3. Editor plugin is a generated example editor to create and modify instances of a model. 4. Test plugin contains templates to write tests cases for a model. 

jgs 564 00010100 Step 3 :: Generate Code § Right click the model folder in the project then § New → Other… → EMF Generator Model → Next § and enter myModel.genmodel as the file name. § Select Ecore model as the model importer. § select Browse Workspace… and select our previously created myModel.ecore 

jgs 564 00010100 Step 3 :: Generate Code § Based on the generator model, we can now generate the source code. § EMF allows you to generate 4 different plugins. § To generate the plugins, right-click on the root node of the genmodel and select the plugin. For our tutorial, please select “generate all”. 

jgs 564 00010100 Step 3 :: Generate Code 

jgs 564 00010100 Step 3 :: Generate Code Could you create a class diagram for the package myModel? 

jgs 3. Code 

jgs 564 00010100 § For each class in your model, there is a corresponding generated § Java interface § Java implementation class § For each package, there is a § XXXPackage interface and implementation class § XXXFactory interface and implementation class 

jgs 564 00010100 § These are singletons, to access the instances use § XXXPackage.eINSTANCE § XXXFactory.eINSTANCE § Use the Factory to create instances of your model classes, e.g: TaskList t = ExampleFactory.eINSTANCE.createTaskList(); § Use the Package to access the meta-model definition, e.g: EClass c = ExamplePackage.eINSTANCE.getTaskList(); List attrs = c.getEAttributes(); 

jgs 564 00010100 Interfaces package myModel; public interface Course extends EObject { String getName(); void setName(String value); EList getStudents(); } public interface Student extends EObject { String getName(); void setName(String value); int getGpa(); void setGpa(int value); boolean isHasScholarship(); void setHasScholarship(boolean value); Computer getComputer(); void setComputer(Computer value); } public interface Computer extends EObject { String getBrand(); void setBrand(String value); } 

jgs 564 00010100 Interfaces package myModel; public interface MyModelFactory extends EFactory { MyModelFactory eINSTANCE = myModel.impl.MyModelFactoryImpl.init(); Course createCourse(); Student createStudent(); Computer createComputer(); MyModelPackage getMyModelPackage(); } public interface MyModelPackage extends EPackage { String eNAME = "myModel"; String eNS_URI = "https://org/eclipse/example/myModel"; String eNS_PREFIX = "org.eclipse.example.myModel"; MyModelPackage eINSTANCE = myModel.impl.MyModelPackageImpl.init(); // more ... } 

jgs 564 00010100 Classes :: Course package myModel.impl; public class CourseImpl extends MinimalEObjectImpl.Container implements Course { protected static final String NAME_EDEFAULT = null; protected String name = NAME_EDEFAULT; protected EList students; protected CourseImpl() { super(); } @Override protected EClass eStaticClass() { return MyModelPackage.Literals.COURSE; } @Override public String getName() { return name; } @Override public void setName(String newName) { String oldName = name; name = newName; if (eNotificationRequired()) eNotify(new ENotificationImpl(this, Notification.SET, MyModelPackage.COURSE__NAME, oldName, name)); } // continue ... 

jgs 564 00010100 Classes :: Course @Override public EList getStudents() { if (students == null) { students = new EObjectContainmentEList (Student.class, this, MyModelPackage.COURSE__STUDENTS); } return students; } // more ... @Override public String toString() { if (eIsProxy()) return super.toString(); StringBuilder result = new StringBuilder(super.toString()); result.append(" (name: "); result.append(name); result.append(')’); return result.toString(); } } 

jgs 564 00010100 Classes :: Student package myModel.impl; public class StudentImpl extends MinimalEObjectImpl.Container implements Student { protected boolean hasScholarship = HAS_SCHOLARSHIP_EDEFAULT; protected Computer computer; @Override public void setComputer(Computer newComputer) { Computer oldComputer = computer; computer = newComputer; if (eNotificationRequired()) eNotify(new ENotificationImpl (this, Notification.SET, MyModelPackage.STUDENT__COMPUTER, oldComputer, computer)); } @Override public Computer getComputer() { if (computer != null && computer.eIsProxy()) { InternalEObject oldComputer = (InternalEObject)computer; computer = (Computer)eResolveProxy(oldComputer); if (computer != oldComputer) { if (eNotificationRequired()) eNotify(new ENotificationImpl (this, Notification.RESOLVE, MyModelPackage.STUDENT__COMPUTER, oldComputer, computer)); } } return computer; } } 

jgs 564 00010100 Why is This Better than Writing POJOs? § plain old Java object (POJO) § We have generated over 1,000 LOC, § Even very simple code is considered to be worth $1 per LOC. So, $1,000 just by clicking some buttons 

jgs 564 00010100 Questions 

jgs 564 00010100 Reference § Eclipse Modeling Framework by Frank Budinsky § EMF project on eclipse.org 

jgs CSE 564 Computer Systems Fundamentals Javier Gonzalez-Sanchez [email protected] Fall 2020 Disclaimer. These slides can only be used as study material for the class CSE564 at ASU. They cannot be distributed or used for another purpose.