POLITECNICO DI MILANO
Dipartimento di Elettronica e Informazione
DEEPSE Group
MASHLIGHT:
A
LIGHTWEIGHTMASHUPFRAME
WORKFOREVERYONE
M. Albinola, M. Carcano,
L. Baresi, S.Guinea
2nd Workshop on Mashups, EnterpriseMashups
and LightweightComposition on the Web

2
Mashups in a nutshell
• Reuse and integrationofcomponents
▫ Lower design and developmentcosts
▫ Lowertime-to-market
• Software as a Service (SaaS)
▫ Simple and lightweightmodel
▫ Universallyaccessible (through a browser)
▫ No needtoinstall
• Do-it-yourself (DIY)
▫ Anyone can beanauthor
▫ On–the-flydevelopment

3
Mashlightgoals
Qualitydimensions:
▫ Flexibility
 Suppportforallthree “natures”
(Data, Logic and Presentation)
▫ Usability
 Abstractionlevelthatanykindofuser can understand
(End Users and Developers)
▫ Lightweight
 Can bedeployedtodifferentkindsofdevices
(Android/iPhone)

4
Mashlight: the Idea
Starting Point:
Mashups are createdthrough the process-
likedispositionoflogicactivities
Maincharacteristics:
• Single activities are Web 2.0 applications
▫ Mac OS XDashboard, Vista sidebar, etc.
• Processlanguageisextremelysimple
▫ Blocksdefineabstractionlevel
• Show oneactivity at a time
▫ Provideintrinsicrollback

5
The Model: MashlightBlocks
Independentfunctionalunitwithclear goal
▫ Es: Weather service, calculator, yellow pages,
Remote Service Invocation
• Parameters input
Block Block
output
entry connection
• Links Block
Block
outlink
outlink2
outlink1
outlink1

6
Real-worldblocks…
• Widgetlike Web 2.0 applications
• Modifiedversionsof Google Widgets
▫ Supportfor I/O parameters
▫ SupportforinteractionwithMashlightEngine

7
The Model: MashlightProcesses
• Graphrepresentationof the process
▫ Activationorder (Process Flow)
▫ Data dependencies (Data Flow)
Process Flow Execution Flows Data Flow
A
A A
A
B
B D
D
B D
C E
C E
C E
E
• High levelofabstraction
▫ No explicitconditional branching or looping

8
The Model: AdvancedAspects
Execution flow
• Complex Data A B C
Assignment A
B
street
city
address.city
address.street
C
• Data with Multiple
Cardinality A A A
address[1].stree address[1].city
city address[2].cit
t street address[*].city
y
B B B
• Prioritized data A B
A
assignments address[2].street address[1].city
address[1].city
city[*]
address.street address.city
B
C

9
The Model: AdvancedAspects
• Undooperation
▫ Goes back to the beginningof the
previouslycompleted block
Process Flow
Evolutionof the execution flow
A A A
A
D B D
B D
E C
C E
1 2 3

10
Mashlight: architecture
• Fourmainmodules
Runtime
Engine
Blocks Library
Block
Mashup Mashup
Builder Process
Block Builder

11
RuntimeEngine
Control toolbar
Map
Mashup area

12
Example-NightPlan
Userwantstoorganize a night out:
restaurant + cinema
Mashlightblocks:
▫ PagineGialle
 Italian Yellow Pages
▫ Google Maps
 Visualizationof interest point
▫ MovieTickets
 Buy tickets online
▫ Google Maps Navigator
 Mapdrivinginstructions
DEMO

13
Process Flow Data Flow
what: ristorante
where: Milano
streetName: piazza leonardo false
searchQuery autoQuery
A - PagineGialle
A - Pagine gialle
out
resultItem.coordinates
resultItem.coordinates
address coordinates
resultItem.city
B - Google Maps cinema
B - Google Maps
resultItem.address
out
false
searchQuery autoQuery
C - PagineGialle
C - Pagine gialle
out
resultItem.name resultItem.coordinates
address coordinates
D - Google Maps
B - Google Maps
out Matteo
CinemaName accountUsername
E - MovieTickets
E - MovieTickets
out
resultItem.coordinates
steps[0] travelMode
from to
F - Google Maps
F - Google Maps
Navigator
Navigator
city: Milano
out
address: via Golgi, 40

14
Future Work
• EnrichlibraryofMashlightblocks
▫ Specificblocksforspecificdomains
• Block Builder
▫ Eclipsepluginforsemi-automatic block creation
▫ WADL-generatedMashlightblocks
• Mashup Builder
▫ Generalpurposeprocess design environment
▫ Domain-
specificabstractionsthatuseMashlightasbackend
• Supportfor mobile devices
▫ Processstarts on PC and continues on Android/iPhone

15
Example - Prototype
Developerwantstoprototype service
interactions
Mashlightblocks:
▫ SOAP Client
 Service invocationthrough SOAP
▫ Selector
 Selectorcomponentsimilartoforeach
in programminglanguages
▫ Choose
 Chooseanoutlinkbased on
conditionparameter

16
Process flow Data flow
http://www. getList
methodName parameter
wsdlUrl
s
A - SoapClient
A - SoapClient
ok
soapResponseObjects
soapResponseXml
itemIndex itemList
0
B - Selector
B – Selector
end
loop selectedItemIndex
nextItemIndex
item
parameters[0
getList methodName
]
wsdlUrl
http://www.
C - SoapClient
C - SoapClient
ok
soapResponseXml soapResponseObjects[0]
condition
D - Choose
D – Choose
false
true
getList parameter
wsdlUrl methodName
s
http://www.
E - SoapClient
E - SoapClient
ok
soapResponseXml soapResponseObjects
methodName parameters[1]
wsdlUrl
getList
parameters[0]
F - SoapClient
F - SoapClient
http://www.
ok
soapResponseObjects
soapResponseXml