Fast introduction to the most innovative framework to build web applications

1. JL-1
Roma <Meta>
Framework
Introduction and main concepts
Luca Garulli
CTO@AssetData.it CTO at AssetData, Technical Manager
at Romulus consortium, Author of
http://zion-city.blogspot.com Roma Framework and OrientDB Open
http://twitter.com/lgarulli Source projects

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
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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”
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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
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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
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6. Aspects
Authentication •Scheduler
•Flow •Security
•Enterprise •Semantic
•Hook •Serialization
•I18n (internationalization) •Service
•Logging •Session
•Monitoring •Validation
•Persistence •View
•Registry •Workflow
•Reporting
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7. POJO is the answer for all
•POJO •
•
•(Plain Old Java Object)
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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?
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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!
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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?
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11. Enriched Meta Model III
•We need a way to enrich the meta-model using
Java5+ Annotations or Xml Annotations
•ContactInstance.java:
•
•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. 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(){...}
•}
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13. Auto rendering: POJO → Form
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14. Binding POJO ↔ Form
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15. Composite Forms
•To build complex forms you need to composite
POJOs all together
•ContactInstance.java:
•
•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(){
• ...
• }
•}
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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”.
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17. Extension by composition II
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18. Getting started!
Connect to http://www.romaframework.org
Download latest version
Download the Handbook
Start with the first tutorial
Ask to the forum or the online support
Enjoy!
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19. Demo pleeeease!
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