presentation evrythng

A Model-Driven, Component Generation Approach for the WoTUniversity of Fribourg

Overview

• Vision

• Short Technological Background

• The xWoT

• A component approach for the xWoT

• Meta-Modeling

• The xWoT Compiler

• S2Mashup Editor

• Semantic Discovery for the xWoT

Université de fribourg | FACULTÉ des sciences | Andreas / Ruppen | A Model-Driven, Component Generation Approach for the WoT

08/07/2015

INTRODUCTION& Vision


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Vision

• Instead of finding better approaches on how to combine smart devices we have to re-think how to build smart devices.• The current WoT needs to be extended to take into consideration

algorithms and handle events gracefully.

• Re-usable and easy to deploy components, taking care of aspects like events (and discovery in the future) are the way out of the “things-crisis”.

• Adopt Model Driven Architecture.

• Allow Models to be enhanced semantically.


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BACKGROUNDHistorical and Technological


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Software Components

• According to Cox the solution to the software crisis in the early 80’s.

• A software component is a unit of composition with contractually specified interfaces and explicit context dependencies only. A software component can be deployed independently and is subject to composition by third parties. (Szyperski)


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Meta-Model

• Given• α:S→M

• Then

• ∃ SUS1, SUS2 ∈ S|α(SUS1) = α(SUS2) ⇏SUS1 = SUS2


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Meta-Model

• Given• α′ : M → MM

• Then• ∃ m1,m2 ∈ M | α′

(m1) = α′(m2) ⇏ m1 = m2


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The xWoTAn Extension for the WoT


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WoT Problems

• Data Integration: Treat Algorithms and other RESTful services as first class citizens.

• Event Architecture: Define a common event architecture suitable for a wide range of applications.

• Building Blocks: Introduce components as the building blocks of the xWoT.


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Data Integration

• Mashups already rely on services like Facebook or Twitter.

• How to turn a Book into a Smart-Book?• Leveraging the power of established computational

resources to the WoT, e.g. Business Processes.


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Events

• Today: use of IoTaaS platforms like Xively.• Problem: Smart-Devices are no longer WoT Compliant.

Instead the IoTaaS Platform is.• Events must propagate in an (energy) efficient manner.• WebHooks: spare events, alerting• WebSockets: many events, live monitoring


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Components

• Hide the inner guts from clients.• Define a clear interface for users (RESTful).• Build reusable components.• Use Meaningful URIs.• Use Predictable URIs (plus HATEOAS)


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Formal Definition

• The extended WoT is a web made of sensors, actuators and tags forming the classical WoT plus services respecting RESTful principles.

• The aim of the xWoT is to introduce a standard approach on how to design the building blocks for novel applications and mashups exploiting the capabilities offered by smart things and other virtual goods. To achieve this goal, the xWoT introduces a component- based methodology which is underlined by a meta-model guiding the developers during crucial architectural decisions. Finally, since the architecture respects the xWoT’s meta-model, component skeletons are generated out of the specifications.


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COMPONENTSReusable xWoT Components


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Corridor - ExampleUniversité de fribourg | FACULTÉ des sciences | Andreas / Ruppen | A Model-Driven, Component Generation Approach for the WoT

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Expected Output

• One component representing the corridor.• One component for each instantiated corridor.


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SmartDoor Component

http://service1.com/door/ GET

http://service1.com/door/oc/ GET / PUT

http://service1.com/door/oc/pub/ various

http://service1.com/door/lu/ GET / PUT

http://service1.com/door/lu/pub/ variousSmartCorridor

http://service2.com/corridor/ GET

http://service2.com/corridor/{id} GET

http://service2.com/corridor/{id}/oc GET / PUT

http://service2.com/corridor/{id}/oc/pub/ various

http://service2.com/corridor/{id}/lu/ GET / PUT

http://service2.com/corridor/{id}/lu/pub/ various

META-MODELINGThe xWoT Meta-Model


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Partial xWoT Meta-Model

Virtual Entity

Resource

Actuator Resource

Sensor Resource

Service Resource

1..*

Publisher Resource

Context Resource

Physical Entity

Entity

0..1 1

DeviceTag SensorActuator

1..*


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Full xWoT Meta-Model

Virtual Entity

Resource

Actuator Resource

Sensor Resource

Service Resource

1..*

Publisher Resource

Context Resource

Physical Entity

Entity

0..1 1

DeviceTag SensorActuator

1..*

name: EStringmethod: MethodOperationoutput: MethodOutputinput: MethodInput

Method

style: MethodStyleMethodParam

style: MethodStyleVEntityParam

name: EStringtype: EString

ParamTEMPLATEQUERY

MethodStyleXMLJSONMULTIPARTRELATEDFORMNONE

MethodInputXMLJSONMULTIPARTRELATEDFORMNONE

MethodOutputGETPUTPOSTDELETE

MethodOperation

0..* 0..*

0..*


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Smart Door Example (UC)Université de fribourg | FACULTÉ des sciences | Andreas / Ruppen | A Model-Driven, Component Generation Approach for the WoT

08/07/2015

Smart Door Example (HW)Université de fribourg | FACULTÉ des sciences | Andreas / Ruppen | A Model-Driven, Component Generation Approach for the WoT

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Smart Door Example (M)Université de fribourg | FACULTÉ des sciences | Andreas / Ruppen | A Model-Driven, Component Generation Approach for the WoT

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COMPILERA Model Compiler for the xWoT


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Model Enhancer

• Since there is a one-to-one mapping from the Physical Entity to the Virtual Entity, for each physical model, its virtual side can be generated.

• The generated virtual side can be further refined manually.

• Takes as input an xWoT Model and generates a new, enhanced xWoT Model.

• Where additional information is needed, the compiler asks for user input.


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Smart Door Example (rev)Université de fribourg | FACULTÉ des sciences | Andreas / Ruppen | A Model-Driven, Component Generation Approach for the WoT

08/07/2015

Model Compiler

• Once the model finished, it can be compiled into code skeletons.

• The compiler takes care of:• Resources hierarchy.

• Allowed Methods.

• It can generate:• Python Code (Autobahn)

• Node.js

• Etc.


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Model Compiler

• Takes as input an xWoT model and automatically generates a REST service for each component.

• Each components contains code skeletons to be filled in by the developer.


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Smart Door Example (rev)Université de fribourg | FACULTÉ des sciences | Andreas / Ruppen | A Model-Driven, Component Generation Approach for the WoT

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Reusability

• The Compiler takes care of:• The reusability of the generated components.• To create a new RESTful service for each Composite

(according to the composed flag).

• Of the Application Scenario Service


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Smart Room Example (UC)Université de fribourg | FACULTÉ des sciences | Andreas / Ruppen | A Model-Driven, Component Generation Approach for the WoT

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METHODOLOGY


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Three Steps

• Entity Modeling (blue)• Data Modeling (green)• Implementation (yellow)


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Methodology

Implement HTTP Responses

Define Entity

Model Entity

Physical2

Virtual

RESTSkeleton

ModelPhysical Entity

ModelVirtual Entity

RefineVirtual Entity

Create SeverSkeleton

Link Code to Hardware

Build Hardware

Model Representations

CreateXSD

Create Code Artifacts

Model Database

CreateERM

Forward Engineer

DB

Create Code

Artifacts


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S2MashupSmart, Semantic Mashup Editor

Ingredients

• Consumer friendly Mashup Editor (drag and drop).

• Include Semantics:• Discovery.

• Late-Binding.

• (Semi)-Automatic-Binding.

• Write once, deploy everywhere.

08/07/2015Université de fribourg | FACULTÉ des sciences | Andreas / Ruppen | A Model-Driven, Component Generation Approach for the WoT

DISCOVERYA quick Outlook


Requirements

• Implement a discovery mechanism respecting RESTful principles (as far as applicable).

• Inject semantics into the discovery based on the meta-model.

• Extend semantics depending on a situation’s needs.• Adopt current standards (JSON-LD, Tuples)


Limitations

• Implementation based on multicast/unicast between devices.

• Limited to the multicast network boundaries.• Startup a little wiggly.


Demo08/07/2015


CONCLUSION& Outlook


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Benefits

• Allow fast prototyping.

• Support developers.

• Give end users the possibility to build re-usable mashup applications.


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Future Work

• Bring the different projects together• S2Mashup

• Semantics

• Discovery

• Meta-Model

• Propose a fully integrated tool for developers as well as for end users to either create new smart Things or exploit deployed ones.


presentation evrythng

Software

component approach

component generation

fribourg facult

sciences andreas ruppen

model driven architecture

xwot universit

sus2 universit

m2 universit