QScxmlDataModel Class

The QScxmlDataModel class is the data model base class for a Qt SCXML state machine. More...

Header: #include <QScxmlDataModel>
qmake: QT += scxml
Since: Qt 5.7
Inherits: QObject
Inherited By:

QScxmlCppDataModel, QScxmlEcmaScriptDataModel, and QScxmlNullDataModel

This class was introduced in Qt 5.7.

Public Types

Properties

Public Functions

QScxmlDataModel(QObject *parent = nullptr)
virtual void evaluateAssignment(QScxmlExecutableContent::EvaluatorId id, bool *ok) = 0
virtual void evaluateForeach(QScxmlExecutableContent::EvaluatorId id, bool *ok, QScxmlDataModel::ForeachLoopBody *body) = 0
virtual void evaluateInitialization(QScxmlExecutableContent::EvaluatorId id, bool *ok) = 0
virtual bool evaluateToBool(QScxmlExecutableContent::EvaluatorId id, bool *ok) = 0
virtual QString evaluateToString(QScxmlExecutableContent::EvaluatorId id, bool *ok) = 0
virtual QVariant evaluateToVariant(QScxmlExecutableContent::EvaluatorId id, bool *ok) = 0
virtual void evaluateToVoid(QScxmlExecutableContent::EvaluatorId id, bool *ok) = 0
virtual bool hasScxmlProperty(const QString &name) const = 0
virtual QVariant scxmlProperty(const QString &name) const = 0
virtual void setScxmlEvent(const QScxmlEvent &event) = 0
virtual bool setScxmlProperty(const QString &name, const QVariant &value, const QString &context) = 0
void setStateMachine(QScxmlStateMachine *stateMachine)
virtual bool setup(const QVariantMap &initialDataValues) = 0
QScxmlStateMachine *stateMachine() const

Signals

void stateMachineChanged(QScxmlStateMachine *stateMachine)

Protected Functions

QScxmlDataModel(QScxmlDataModelPrivate &dd, QObject *parent = nullptr)

Detailed Description

SCXML data models are described in SCXML Specification - 5 Data Model and Data Manipulation. For more information about supported data models, see SCXML Compliance.

One data model can only belong to one state machine.

See also QScxmlStateMachine, QScxmlCppDataModel, QScxmlEcmaScriptDataModel, and QScxmlNullDataModel.

Property Documentation

stateMachine : QScxmlStateMachine*

This property holds the state machine this data model belongs to.

A data model can only belong to a single state machine and a state machine can only have one data model. This relation needs to be set up before the state machine is started. Setting this property on a data model will automatically set the corresponding dataModel property on the stateMachine.

Access functions:

QScxmlStateMachine *stateMachine() const
void setStateMachine(QScxmlStateMachine *stateMachine)

Notifier signal:

void stateMachineChanged(QScxmlStateMachine *stateMachine)

Member Function Documentation

[protected] QScxmlDataModel::QScxmlDataModel(QScxmlDataModelPrivate &dd, QObject *parent = nullptr)

Creates a new data model from the private object dd, with the parent object parent.

QScxmlDataModel::QScxmlDataModel(QObject *parent = nullptr)

Creates a new data model, with the parent object parent.

[pure virtual] void QScxmlDataModel::evaluateAssignment(QScxmlExecutableContent::EvaluatorId id, bool *ok)

Evaluates the assignment pointed to by id and sets ok to false if there was an error or to true if there was not.

[pure virtual] void QScxmlDataModel::evaluateForeach(QScxmlExecutableContent::EvaluatorId id, bool *ok, QScxmlDataModel::ForeachLoopBody *body)

Evaluates the foreach loop pointed to by id and sets ok to false if there was an error or to true if there was not. The body is executed on each iteration.

[pure virtual] void QScxmlDataModel::evaluateInitialization(QScxmlExecutableContent::EvaluatorId id, bool *ok)

Evaluates the initialization pointed to by id and sets ok to false if there was an error or to true if there was not.

[pure virtual] bool QScxmlDataModel::evaluateToBool(QScxmlExecutableContent::EvaluatorId id, bool *ok)

Evaluates the executable content pointed to by id and sets ok to false if there was an error or to true if there was not. Returns the result of the evaluation as a boolean value.

[pure virtual] QString QScxmlDataModel::evaluateToString(QScxmlExecutableContent::EvaluatorId id, bool *ok)

Evaluates the executable content pointed to by id and sets ok to false if there was an error or to true if there was not. Returns the result of the evaluation as a QString.

[pure virtual] QVariant QScxmlDataModel::evaluateToVariant(QScxmlExecutableContent::EvaluatorId id, bool *ok)

Evaluates the executable content pointed to by id and sets ok to false if there was an error or to true if there was not. Returns the result of the evaluation as a QVariant.

[pure virtual] void QScxmlDataModel::evaluateToVoid(QScxmlExecutableContent::EvaluatorId id, bool *ok)

Evaluates the executable content pointed to by id and sets ok to false if there was an error or to true if there was not. The execution is expected to return no result.

[pure virtual] bool QScxmlDataModel::hasScxmlProperty(const QString &name) const

Returns true if a property with the given name exists, false otherwise.

[pure virtual] QVariant QScxmlDataModel::scxmlProperty(const QString &name) const

Returns the value of the property name.

See also setScxmlProperty().

[pure virtual] void QScxmlDataModel::setScxmlEvent(const QScxmlEvent &event)

Sets the event to use in the subsequent executable content execution.

[pure virtual] bool QScxmlDataModel::setScxmlProperty(const QString &name, const QVariant &value, const QString &context)

Sets a the value value for the property name.

The context is a string that is used in error messages to indicate the location in the SCXML file where the error occurred.

Returns true if successful or false if an error occurred.

See also scxmlProperty().

void QScxmlDataModel::setStateMachine(QScxmlStateMachine *stateMachine)

Sets the state machine this model belongs to to stateMachine. There is a 1:1 relation between state machines and models. After setting the state machine once you cannot change it anymore. Any further attempts to set the state machine using this method will be ignored.

Note: Setter function for property stateMachine.

See also stateMachine().

[pure virtual] bool QScxmlDataModel::setup(const QVariantMap &initialDataValues)

Initializes the data model with the initial values specified by initialDataValues.

Returns false if parse errors occur or if any of the initialization steps fail. Returns true otherwise.

Note: This function can be invoked via the meta-object system and from QML. See Q_INVOKABLE.

QScxmlStateMachine *QScxmlDataModel::stateMachine() const

Returns the state machine associated with the data model.

Note: Getter function for property stateMachine.

See also setStateMachine().

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