Roma introduction and concepts


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Fast introduction to the most innovative framework to build web applications

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Roma introduction and concepts

  1. 1. JL-1 Roma <Meta> Framework Introduction and main concepts Luca Garulli CTO at AssetData, Technical Manager at Romulus consortium, Author of Roma Framework and OrientDB Open Source projects
  2. 2. Development Scenario I Choose the right framework between hundreds Each framework is proprietary, so migration is too much difficult, or sometimes impossible Learning curve often is steep and requires a lot of time to learn before to understand if it's the right one for us 2
  3. 3. Development Scenario II What happens if you discover that the tool or the framework you choose doesn’t support some features we need or that the best choice was another one? Changing it’s too costly, sometime “impossible” 3
  4. 4. Do you need a <meta> framework? Set of behavior interfaces instead of framework APIs directly. The aim is to cover the 80-90% of the most common use cases. For the uncovered 10- 20% you can use the framework implementation directly Migration to another supported framework without change the code 4
  5. 5. Domain centric view Echo2 Janiculum Modules can implement JDO Java Resource aspects of the JPA View Bundle meta-framework Internatio Persistence (repository) nalization (I18N) CRUD Domain model Login Custom, Http Authentication and Session LDAP business Portlet User & Profile logic Jetty Workflow Others Monitoring Tevere Aspects define the interfaces JMX (behaviour) of the meta-framework 5
  6. 6. Aspects Authentication •Scheduler •Flow •Security •Enterprise •Semantic •Hook •Serialization •I18n (internationalization) •Service •Logging •Session •Monitoring •Validation •Persistence •View •Registry •Workflow •Reporting 6
  7. 7. POJO is the answer for all •POJO • • •(Plain Old Java Object) 7
  8. 8. Everything is a POJO •The application model is composed by POJOs • •The domain entities synchronized with the database are POJOs The Business Logic is written in POJOs • •The Web Services are POJOs • •Guess the Web pages? 8
  9. 9. Enriched Meta Model I •Roma auto discovers all the model of your •application and generate: • •Forms, •Database tables •OR-mapping configuration, •Web services, •and much more! 9
  10. 10. Enriched Meta Model II •But Java as language is not enough to express a complete model. What means this? • •private List<Contact> contacts; • •Is it a relationship? 1-N or N-M? If yes it's embedded or not? • •How can I render it in my Web Page? •A List, a Table or a Select field? 10
  11. 11. Enriched Meta Model III •We need a way to enrich the meta-model using Java5+ Annotations or Xml Annotations • • •public class ContactInstance{ • @ViewField(render = ViewConstants.RENDER_TABLE) Java5+ Annotations pro: • private List<Contact> contacts; All in one file, •} faster to write •ContactInstance.xml: • •<?xml version="1.0"?> Xml Annotations pro: •<class> • <fields> Use of separate files so the • <field name="contacts"> Java sources remain clean • <aspects> • <view render="table"/> • </aspects> • </field> • </fields> •</class> 11
  12. 12. Auto rendering: POJO instead of GUI components •public class User { • private String name; • private String surname; • private City city; • private String web; • • @ViewField(render=”textarea”) • private String notes; • • public void ok(){...} • public void cancel(){...} • public void print(){...} •} 12
  13. 13. Auto rendering: POJO → Form 13
  14. 14. Binding POJO ↔ Form 14
  15. 15. Composite Forms •To build complex forms you need to composite POJOs all together • • •public class ContactForm { • @ViewField(render = “objectembedded”, label=”Personal Information”) • private Contact me; • • @ViewField(render = “tab”) • private Contact[] colleagues = new Contact[]{ • new Contact(“Joy”,“Miner”), • new Contact(“Tim”, “King”) }; • • @ViewField(style = “{width: 400px;}”) • private String description; • • public void sendEmail(){ • ... • } •} 15
  16. 16. Extension by composition I Classic Inheritance Extension by Composition ComposedEntityInstance Employee <Employee> EmployeeFilter EmployeeFilter Doesn't work very well with some All Employee fields and actions frameworks such as JDO and are merged with Employee ones. Hibernate: you need to use the You can override fields, actions class declared in the ORMapping and events just redefine it in the tool and not its extension. EmployeeFilter class. The object contained is in the field called “entity”. 16
  17. 17. Extension by composition II 17
  18. 18. Getting started! Connect to Download latest version Download the Handbook Start with the first tutorial Ask to the forum or the online support Enjoy! 18
  19. 19. Demo pleeeease! 19