Slides of our paper "EMF-REST: Generation of RESTful APIs from Models"

1. Hamza Ed-douibi, Javier Luis Cánovas
Izquierdo, Abel Gómez, Massimo Tisi, Jordi
Cabot
EMF-REST: Generation of RESTful
APIs from Models
1
ACM SAC 2016 - Pisa, Italy.
07/04/2016

2. EMF-REST: Generation of RESTful APIs
from Models
2
 The Model-driven engineering paradigm emphasizes the use of
models to raise the level of abstraction and to (semi)automate the
development of software.
Abstraction
Automation
MDE
Standar-
dization
 The Eclipse Modeling Framework (EMF) is the foundation for
modeling and data integration at Eclipse. (Models are described using
the Ecore language)

3. EMF-REST: Generation of RESTful APIs
from Models
3
Addressable resources (URI)
Representation-oriented (JSON,XML)
Statelessness
Uniform and Constrained Interface
Representational State Transfer (REST) is an architectural style
that specifies constraints such as:

4. Java
Environment
XMI
EMF-REST proposal
4
JAVA
+
Web
Environment
JAVASCRIPT
+
REST API
EMF-REST

5. EMF-REST benefits
5
Collaboration Scalability
Portability

6. EMF-REST approach
 EMF-REST generates RESTful Web APIs out of EMF
models.
 The generated API provides a direct mapping to
access data models following the REST principles :
– Addressable resources (URI)
– Representation-oriented (JSON,XML)
– Statelessness
– Uniform and Constrained Interface (HTTP verbs :
GET, POST,…)
 The generated application supports validation and
security.
 The generated RESTful Web API relies on well-known
libraries and standards.
6

7. EMF-REST features
7
REST API JSON Serialization XML Serialization
Validation Security

8. Running Example
8
IFML (Interaction Flow Modeling Language) model: A
form from a movie manager

9. Mapping EMF with REST
EMF
EMF-REST
9
Addressable resources
1. platform:/resource/project/AddMovie.xmi
2. platform:/resource/project/AddMovie.xmi#title
3. platform:/resource/project/AddMovie.xmi#//.../@viewComponentsParts.0
1. https://example.com/rest/IFMLModel/AddMovie
2. https://example.com/rest/IFMLModel/.../viewComponentsParts/title
3. https://example.com/rest/IFMLModel/.../viewComponentsParts?index=0

10. Mapping EMF with REST
XML JSON
10
Representation-Oriented
<form>
<name>AddMovieForm</name>
<viewComponentParts>
<simpleField>
<uri>https://example.com/.../
viewComponentsParts/picture</uri>
</simpleField>
<simpleField>
<uri>https://example.com/.../
viewComponentsParts/title</uri>
</simpleField>
...
</viewComponentParts>
<viewElementEvents>
<onSubmitEvent>
<uri>https://example.com/.../
viewElementEvents/add</uri>
</onSubmitEvent>
</viewElementEvents>
</form>
{
"form":{
"name":"addMovieForm",
"viewComponentParts":{
"simpleField":[
{
"uri":"https://.../
viewComponentsParts/picture"
},
{
"uri":"https://.../
viewComponentsParts/title"
}
,…]
},
"viewElementEvents":{
"onsubmitevent":{
"uri":"https://.../
viewelementevents/add"
}
}
}
}

11. Mapping EMF with REST: Uniform and
Constrained Interface & Statelessness
EMF
EMF-REST
11
PUT https :// example .com/rest/IFMLModel/AddMovie/
interactionFlowElements/AddMovieWindow/
viewElements /AddMovieForm
{"form":{
name :"toto"
}
}
addMovieFormObj . setName (" toto ");
//addMovieFormObj is of type Form

12. Extra features
 Validation
– Use of OCL annotations to enable validation each time the API is called
 Security
– Encryption: All the communications with the server are using HTTPS
– Authentication: Only authenticated users are allowed to access the API
– Authorization: Use of a Role-based mechanism to assign permissions for
each operation.
– Use of model annotations to support authentication and authorization
12

13. Architecture of EMF-REST generated application
13
EMF
JAX-RS
EJB/CDI
JAXB OCL JPA
JavaScript API
Browser
REST Client
Validation SecurityContent management
Web ClientWeb Application

14. EMF-REST generation process
14

15. Conclusion & future work
 EMF-REST generates truly RESTful APIs for EMF
models by mapping data models with REST
principles.
 EMF-REST complements the existing (Java-based) API
generation facilities EMF already provides and
extends them to the Web.
 Future work:
– Storage configuration
– Configuration of the generated API
– Definition of how model elements should be
serialized.
15

16. Thank you!
16
• Visit us at:
http://som-
research.uoc.edu/tools/emf-rest/
• Hamza Ed-douibi:
hed-douibi@uoc.edu
•Javier Cánovas:
jcanovasi@uoc.edu
•Jordi Cabot:
jordi.cabot@icrea.cat