Executable UML modeling in txtUML

Agenda

● Part I: Introduction● Part II: Class modeling● Part III: State modeling● Part IV: Executable modeling● Part V: Component modeling

Part I: Introduction

Webpage of the toolto be used for this course:

txtuml.inf.elte.hu/

What is modeling?

Abstraction

Software modeling:We use abstractions of real-world objects and notions

in the software programs.We help understanding with graphical diagrams.

What is UML?

● UML = Unified Modeling Language– Standardized modeling language (OMG)– It defines the semantics (= meaning) of model elements, the

ways they can be used and their graphical format– Usage:

business processes, planning of systems and software

Executable UML

● UML is most often used for planningplanning. The plans are then implemented in a programming language (C++, Java, Python, …).

● However, UML is applicable for executable modeling.“The model is the software.”

● Development environments:– BridgePoint: xtuml.org– Papyrus: eclipse.org/papyrus/– txtUML: txtuml.inf.elte.hu

txtUML

● txtUML: Textual, executable, translatable UML– Textual description of models– Generated diagrams– Model execution, debugging possibilities– C++ code can be generated (in progress)

● Developed and maintained by the “Model Driven Development Research Group” at ELTE University, Faculty of Informatics

● Web: txtuml.inf.elte.hu● It is an open source project:

github.com/ELTE-Soft/txtUML

Part II: Class modeling

Object, class

PushOpen

Welcome

Attributes

Operations

Object, class

PushOpen

Welcome

Attributes

Operations

Objects

Class

Class definition in txtUML

Base types: int, boolean, String

Association

Name of association

Role name

“A poem is written byexactly onepoet.”

“A poet can haveany number ofpoems.”

Role name

Multiplicities

Association in txtUML

Association examples

Composition

He wheels are integral partsof a car!

Exactly 4 wheels.

A wheel is mounted onat most one car.Wheels that are not mountedare allowed.

Multiplicity at the container iseither 1 or 0..1.

Composition in txtUML

Generalization

Generalization in txtUML

Class modeling example● Does this model allow

homeless persons?

● How many addresses can a person have?

● Do all family houses have kitchen and garden?

● Can a flat have a garden?

● Can 100 persons live in one single flat?

● Do all gardens have an address?

Class modeling example● Does this model allow

homeless persons?

● How many addresses can a person have?

● Do all family houses have kitchen and garden?

● Can a flat have agarden?

● Can 100 persons live in one single flat?

● Do all gardens have address?

NO

NO

NO

1

YES

NO

Diagram generation using txtUML

● Model + Diagram description ==> Graphical diagram

Diagram generation using txtUML

● The diagram descriptions are Java classes with annotations.● These are not parts of the model, should be placed in a different package.● Available annotations:

– @Show(A.class): “Should be in the diagram, but it does not matter where.”– @Row({A.class, B.class, … }): “In one row.”– @Column({A.class, B.class, … }): “in one column.”– @Left(from = A.class, val = B.class): “B is the left neighbour of A.”– @Right, @Below, @Above: similarly– @Diamond(top = A.class, right = B.class,

bottom = C.class, left = D.class): “Organized in a diamond shape.”– …

● Generation: txtUML menu / Generate diagrams from txtUML

Part III: State modeling

State machineThe class containing the state machine

Initial state

State machine

Initial transition TransitionSignal

State machine in txtUML

Guards

Choice state

Composite states

Composite states in txtUML

What is the problem?

A safer microwave oven :)

State machine diagram generationusing txtUML

The class owning thestate machine.

● Generation:txtUML menu / Generate diagrams from txtUML

Part IV: Executable modeling

Action code

● Action code is a sequence of instructions that are executed when the model is in a given situation.

Location of action code When is it called?

Operation body Operation call

Entry action State machine enters the state

Exit action State machine leaves the state

Effect The transition is executed

Action code examplesOperation(constructor of theMicrowaveOven class)

Entry and exit actionsof a state.

Effect of a transition.

Action code elements

● Local variable definition– int x = 10;– Lamp lamp;

● Value assignment– x = 11;– lamp = otherLamp;

● Basic arithmetic and logic– boolean b = (x < 11) && !(x <= 0)

Action code elements

● Accessing attributes of a class– int x = lamp.serialNumber;

● Operation call– lamp.setSerialNumber(111222);

● Accessing attributes of a signal(in entry, exit or effect)– int x = trigger.data + trigger.otherData

● Control statements– if, for, while (like in Java)

Action code elements

● Object instantiation– Lamp lamp = create(Lamp);

● Starting the state machine of an object– start(lamp);

● Object deletion– delete(lamp);

● Signal sending– send new LampOff() to lamp;– send new SignalWithData(1,false) to myObject;

Action code elements

● Linking objects through an association– link(MicroHasLamp.lamp, myLamp,

MicroHasLamp.micro, myMicro);

● Unlinking objects– link(MicroHasLamp.lamp, myLamp,

MicroHasLamp.micro, myMicro);

Associationends

Objectsto be linked

Action code elements

● Association navigation– Collection<Lamp> lamps = micro->(MicroHasLamp.lamp);

● Selecting one element from the collection– Lamp oneLamp = lamps.selectAny();

● Number of elements in a collection– int num = lamps.count();

● Iteration over the elements– for(Lamp item in lamps) { … }

Starting a model from Java code

● To be completed...

Part V: Component modeling

● To be completed...