spreadsheets are models too - richard paige at sems 2014

1

Spreadsheets are models too

Richard Paige, Dimitris Kolovos, Nicholas Matragkas Department of Computer Science

University of York @richpaige, @kolovos, @nmatragkas

2 MDE

•  Aims to improve the quality and efficiency of the software development process – Promotes models to first-class citizens – Reduces the need for human compilers – Models are purposeful descriptions that are

processable by automated tools. •  Not restricted to a particular modelling

technology / model representation format

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3 Models?

EMF XML XSD

Spreadsheets Visio RDBMS

4 The MDE Community

EMF XML XSD

Spreadsheets

Visio RDBMS

5 Everyone else

EMF

XML XSD

Spreadsheets Visio RDBMS

6 EMF Consolidation?

•  Benefit from modern modelling languages, DSLs, language workbenches, tools.

•  Benefit from use of generic tools for model management (e.g., for transformation, validation, migration).

•  Benefit from consolidated technology platforms. – Possibly better tool interoperability.

7 Spreadsheets for SE •  Versatile and intuitive •  Fill gaps in software development process

– When no specialised tool exist for the job – When specialised tools are too expensive/

complicated – When information needs to be collected from non-

programmers •  Some problems are inherently tabular (e.g.,

certification/assurance arguments, control law modelling, data modelling, traceability).

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8 Spreadsheet = Model

•  Spreadsheets are models with interesting (valuable) properties. – Structure is largely read-only – Fixed implicit metamodel vs variable explicit

metamodel (with EMF/Ecore) •  Model editing vs metamodel then model editing.

– Specialised rather than generic tools. •  Excel/Google Spreadsheets interface vs. Eclipse

interface…

9 Treat Spreadsheets Like (EMF) Models?

•  What are the benefits? – Use generic tools (transformation, validation,

merging, comparison) on spreadsheets. – Support richer heterogeneity in the MDE

space (not just EMF!). – Better support for early stages of SE: bridge

between early requirements and structured modelling.

– Support for large legacy models, e.g., 200 sheet x 500 row sheets, never re-engineered.

10 Treat Spreadsheets Like (EMF) Models (2)

•  What are the benefits? – No need to build DS(M)Ls for tabular

problems. – Synergy with existing skills. – Exploit MDE tools for pattern detection, repair/

update, …. •  Sometimes a spreadsheet is all that’s

needed; EMF and DSLs are overkill.

11 How?

•  Injectors: – Generate models (in EMF) from

spreadsheets. – May need to generate spreadsheets

from models, i.e., some form of (partially) bidirectional transformations.

– Specification blow-up?

12 How? •  Model management operations for

spreadsheets. –  i.e., implement typical MDE operations on

spreadsheets, using spreadsheet APIs, Google Spreadsheet Service etc.

– Transformation, code generation, validation, etc.

•  Badly reinvented wheels? – Weigh against maintaining traditional

spreadsheet interface/interaction model.

13 How? •  Provide a spreadsheet driver for MDE

languages/tools for – Model querying – Model-to-model transformation – Model validation – Model-to-text transformation – Model comparison – Model merging

•  ... so that spreadsheets can be used in any step of an MDE process

14 Basic Idea?

•  Spreadsheet -> Model •  Worksheet -> Type •  Column -> Property •  Row -> Model element

modules

MSD,HCI

F

MSD,RQE

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mt506supervisor

mt506

4 jd5023 SmithJane 22jd501 232 ThompsonJoe

D age

C lastname

Bfirstname

Aid

1

Student Staff

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dj5123 JacksonDaniel HCImt506 MSD,RQE2 ThomasMatthew

D teaches

C lastname

Bfirstname

Aid

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Student Staff

Module

Module

Student Staff ModuleHuman Computer Interaction Spring 4 HCI

D

RQE3 SpringRequirements EngineeringMSD2 AutumnModelling and System Design

C term

Btitle

Aid

1

Mark

Mark

Mark

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jd5023 74ICAR jd5012 62TPOP

D C mark

Bmodule

Astudent

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Student Staff Module Mark

15 eclipse.org/Epsilon

16 Example (Query)

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Student.allInstances-> select(s | s.age >= 18).println();

17 Example (M2T)

modules

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<ul> [%for (s in Student.allInstances){%] <li> [%=s.firstname] [%=s.lastname] [%}%] </ul>

18 Example (Validation)

context Mark { constraint WithinRange { check: self.mark <= 100 and self.mark >= 0 message: “Mark ” + self.mark + “ must be between 0-100”

} }

modules

MSD,HCI

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MSD,RQE

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mt506supervisor

mt506


D age

C lastname

Bfirstname

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1

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C lastname

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19 How?

•  Develop a native spreadsheets driver for Epsilon’s pluggable type system (EMC)

•  Pros – No intermediate artefacts – No stale data – Direct updates to the spreadsheet – Can leverage native querying capabilities

20 Query Translation •  The implementation of primitive query

operations can be overloaded. •  The Google Spreadsheets driver rewrites

(EOL) queries at runtime, e.g., to: – https://spreadsheets.google.com/feeds/list/tb-

<mark-worksheet-guid>/od6/private/full?sq=mark>70

•  Search is performed on the server – Composite queries are supported

21 Conclusions •  How do we interface MDE approaches with

spreadsheets? – Cannot/will not be re-engineered! – Need to use “real” models in combination with

spreadsheets (and other “inferior” tech). •  Currently working on extending Google

Spreadsheets work with annotations. – Health care data project (York+TU/e+Lille).

•  Driver available at: https://code.google.com/p/epsilonlabs/

spreadsheets are models too - richard paige at sems 2014

Technology