A passive item model for a datasync data store. More...

#include <datastoremodel.h>

Inheritance diagram for QtDataSync::DataStoreModel:

Public Slots
void	setTypeId (int typeId)
	WRITE accessor for DataStoreModel::typeId.

void	setTypeId (int typeId, bool resetColumns)
	WRITE accessor for DataStoreModel::typeId.

void	setEditable (bool editable)
	WRITE accessor for DataStoreModel::editable.

void	reload ()
	Reloads all data in the model.

Signals
void	storeError (const QException &exception, QPrivateSignal)
	Emitted when the underlying DataStore throws an exception.

void	typeIdChanged (int typeId, QPrivateSignal)
	NOTIFY accessor for DataStoreModel::typeId.

void	editableChanged (bool editable, QPrivateSignal)
	NOTIFY accessor for DataStoreModel::editable.

Public Member Functions
	DataStoreModel (QObject *parent=nullptr)
	Constructs a model for the default setup. More...

	DataStoreModel (const QString &setupName, QObject *parent=nullptr)
	Constructs a model for the given setup. More...

	DataStoreModel (DataStore store, QObject parent=nullptr)
	Constructs a model on the given store. More...

DataStore *	store () const
	Returns the data store the model works on. More...

QString	setupName () const
	Returns the name of the setup this class operates on. More...

int	typeId () const
	READ accessor for DataStoreModel::typeId.

template<typename T >
void	setTypeId (bool resetColumns=true)
	WRITE accessor for DataStoreModel::typeId.

bool	isEditable () const
	READ accessor for DataStoreModel::editable.

QVariant	headerData (int section, Qt::Orientation orientation, int role=Qt::DisplayRole) const override
	Inherits QAbstractTableModel::headerData.

int	rowCount (const QModelIndex &parent=QModelIndex()) const override
	Inherits QAbstractTableModel::rowCount.

int	columnCount (const QModelIndex &parent) const override
	Inherits QAbstractTableModel::columnCount.

bool	canFetchMore (const QModelIndex &parent) const override
	Inherits QAbstractTableModel::canFetchMore.

void	fetchMore (const QModelIndex &parent) override
	Inherits QAbstractTableModel::fetchMore.

QModelIndex	index (int row, int column=0, const QModelIndex &parent=QModelIndex()) const override
	Inherits QAbstractTableModel::index.

Q_INVOKABLE QModelIndex	idIndex (const QString &id) const
	Returns the index of the item with the given id.

template<typename T >
QModelIndex	idIndex (const T &id) const
	Returns the index of the item with the given id.

Q_INVOKABLE QString	key (const QModelIndex &index) const
	Returns the key of the item at the given index.

template<typename T >
T	key (const QModelIndex &index) const
	Returns the key of the item at the given index.

QVariant	data (const QModelIndex &index, int role=Qt::DisplayRole) const override
	Inherits QAbstractTableModel::data.

bool	setData (const QModelIndex &index, const QVariant &value, int role) override
	Inherits QAbstractTableModel::setData.

Q_INVOKABLE QVariant	object (const QModelIndex &index) const
	Returns the object at the given index. More...

template<typename T >
T	object (const QModelIndex &index) const
	Returns the object at the given index. More...

Q_INVOKABLE QVariant	loadObject (const QModelIndex &index) const
	Loads the object at the given index from the store via DataStore::load. More...

template<typename T >
T	loadObject (const QModelIndex &index) const
	Loads the object at the given index from the store via DataStore::load. More...

Qt::ItemFlags	flags (const QModelIndex &index) const override
	Inherits QAbstractTableModel::flags.

QHash< int, QByteArray >	roleNames () const override
	Inherits QAbstractTableModel::roleNames.

int	addColumn (const QString &text)
	Add a new column with the given title. More...

int	addColumn (const QString &text, const char *propertyName)
	Add a new column and set the given property as its Qt::DisplayRole. More...

void	addRole (int column, int role, const char *propertyName)
	Adds the given property as a new role to the given column. More...

void	clearColumns ()
	Removes all customly added columns and roles.

Public Member Functions inherited from QAbstractTableModel
virtual const QMetaObject *	metaObject () const const

virtual void *	qt_metacast (const char *)

virtual int	qt_metacall (QMetaObject::Call, int, void **)

	QAbstractTableModel (QObject *parent)

virtual QModelIndex	sibling (int row, int column, const QModelIndex &idx) const const override

virtual bool	dropMimeData (const QMimeData *data, Qt::DropAction action, int row, int column, const QModelIndex &parent) override

Public Member Functions inherited from QAbstractItemModel
	QAbstractItemModel (QObject *parent)

bool	hasIndex (int row, int column, const QModelIndex &parent) const const

virtual QModelIndex	parent (const QModelIndex &index) const const=0

virtual bool	hasChildren (const QModelIndex &parent) const const

virtual bool	setHeaderData (int section, Qt::Orientation orientation, const QVariant &value, int role)

virtual QMap< int, QVariant >	itemData (const QModelIndex &index) const const

virtual bool	setItemData (const QModelIndex &index, const QMap< int, QVariant > &roles)

virtual QStringList	mimeTypes () const const

virtual QMimeData *	mimeData (const QModelIndexList &indexes) const const

virtual bool	canDropMimeData (const QMimeData *data, Qt::DropAction action, int row, int column, const QModelIndex &parent) const const

virtual Qt::DropActions	supportedDropActions () const const

virtual Qt::DropActions	supportedDragActions () const const

void	setSupportedDragActions (Qt::DropActions actions)

virtual bool	insertRows (int row, int count, const QModelIndex &parent)

virtual bool	insertColumns (int column, int count, const QModelIndex &parent)

virtual bool	removeRows (int row, int count, const QModelIndex &parent)

virtual bool	removeColumns (int column, int count, const QModelIndex &parent)

virtual bool	moveRows (const QModelIndex &sourceParent, int sourceRow, int count, const QModelIndex &destinationParent, int destinationChild)

virtual bool	moveColumns (const QModelIndex &sourceParent, int sourceColumn, int count, const QModelIndex &destinationParent, int destinationChild)

bool	insertRow (int row, const QModelIndex &parent)

bool	insertColumn (int column, const QModelIndex &parent)

bool	removeRow (int row, const QModelIndex &parent)

bool	removeColumn (int column, const QModelIndex &parent)

bool	moveRow (const QModelIndex &sourceParent, int sourceRow, const QModelIndex &destinationParent, int destinationChild)

bool	moveColumn (const QModelIndex &sourceParent, int sourceColumn, const QModelIndex &destinationParent, int destinationChild)

virtual void	sort (int column, Qt::SortOrder order)

virtual QModelIndex	buddy (const QModelIndex &index) const const

virtual QModelIndexList	match (const QModelIndex &start, int role, const QVariant &value, int hits, Qt::MatchFlags flags) const const

virtual QSize	span (const QModelIndex &index) const const

bool	checkIndex (const QModelIndex &index, QAbstractItemModel::CheckIndexOptions options) const const

void	dataChanged (const QModelIndex &topLeft, const QModelIndex &bottomRight, const QVector< int > &roles)

void	headerDataChanged (Qt::Orientation orientation, int first, int last)

void	layoutChanged (const QList< QPersistentModelIndex > &parents, QAbstractItemModel::LayoutChangeHint hint)

void	layoutAboutToBeChanged (const QList< QPersistentModelIndex > &parents, QAbstractItemModel::LayoutChangeHint hint)

void	rowsAboutToBeInserted (const QModelIndex &parent, int start, int end)

void	rowsInserted (const QModelIndex &parent, int first, int last)

void	rowsAboutToBeRemoved (const QModelIndex &parent, int first, int last)

void	rowsRemoved (const QModelIndex &parent, int first, int last)

void	columnsAboutToBeInserted (const QModelIndex &parent, int first, int last)

void	columnsInserted (const QModelIndex &parent, int first, int last)

void	columnsAboutToBeRemoved (const QModelIndex &parent, int first, int last)

void	columnsRemoved (const QModelIndex &parent, int first, int last)

void	modelAboutToBeReset ()

void	modelReset ()

void	rowsAboutToBeMoved (const QModelIndex &sourceParent, int sourceStart, int sourceEnd, const QModelIndex &destinationParent, int destinationRow)

void	rowsMoved (const QModelIndex &parent, int start, int end, const QModelIndex &destination, int row)

void	columnsAboutToBeMoved (const QModelIndex &sourceParent, int sourceStart, int sourceEnd, const QModelIndex &destinationParent, int destinationColumn)

void	columnsMoved (const QModelIndex &parent, int start, int end, const QModelIndex &destination, int column)

virtual bool	submit ()

virtual void	revert ()

Public Member Functions inherited from QObject
	QObject (QObject *parent)

virtual bool	event (QEvent *e)

virtual bool	eventFilter (QObject watched, QEvent event)

QString	objectName () const const

void	setObjectName (const QString &name)

bool	isWidgetType () const const

bool	isWindowType () const const

bool	signalsBlocked () const const

bool	blockSignals (bool block)

QThread *	thread () const const

void	moveToThread (QThread *targetThread)

int	startTimer (int interval, Qt::TimerType timerType)

int	startTimer (std::chrono::milliseconds time, Qt::TimerType timerType)

void	killTimer (int id)

T	findChild (const QString &name, Qt::FindChildOptions options) const const

QList< T >	findChildren (const QString &name, Qt::FindChildOptions options) const const

QList< T >	findChildren (const QRegExp &regExp, Qt::FindChildOptions options) const const

QList< T >	findChildren (const QRegularExpression &re, Qt::FindChildOptions options) const const

const QObjectList &	children () const const

void	setParent (QObject *parent)

void	installEventFilter (QObject *filterObj)

void	removeEventFilter (QObject *obj)

QMetaObject::Connection	connect (const QObject sender, const char signal, const char *method, Qt::ConnectionType type) const const

bool	disconnect (const char signal, const QObject receiver, const char *method) const const

bool	disconnect (const QObject receiver, const char method) const const

void	dumpObjectTree ()

void	dumpObjectInfo ()

void	dumpObjectTree () const const

void	dumpObjectInfo () const const

bool	setProperty (const char *name, const QVariant &value)

QVariant	property (const char *name) const const

QList< QByteArray >	dynamicPropertyNames () const const

void	destroyed (QObject *obj)

void	objectNameChanged (const QString &objectName)

QObject *	parent () const const

bool	inherits (const char *className) const const

void	deleteLater ()

Properties
int	typeId
	Holds the type the model loads data for. More...

bool	editable
	Specifies whether the model items can be edited. More...

Properties inherited from QObject
	objectName

Additional Inherited Members
Static Public Member Functions inherited from QAbstractTableModel
QString	tr (const char s, const char c, int n)

QString	trUtf8 (const char s, const char c, int n)

Static Public Member Functions inherited from QAbstractItemModel
QString	tr (const char s, const char c, int n)

QString	trUtf8 (const char s, const char c, int n)

Static Public Member Functions inherited from QObject
QString	tr (const char sourceText, const char disambiguation, int n)

QString	trUtf8 (const char sourceText, const char disambiguation, int n)

QMetaObject::Connection	connect (const QObject sender, const char signal, const QObject receiver, const char method, Qt::ConnectionType type)

QMetaObject::Connection	connect (const QObject sender, const QMetaMethod &signal, const QObject receiver, const QMetaMethod &method, Qt::ConnectionType type)

QMetaObject::Connection	connect (const QObject sender, PointerToMemberFunction signal, const QObject receiver, PointerToMemberFunction method, Qt::ConnectionType type)

QMetaObject::Connection	connect (const QObject *sender, PointerToMemberFunction signal, Functor functor)

QMetaObject::Connection	connect (const QObject sender, PointerToMemberFunction signal, const QObject context, Functor functor, Qt::ConnectionType type)

bool	disconnect (const QObject sender, const char signal, const QObject receiver, const char method)

bool	disconnect (const QObject sender, const QMetaMethod &signal, const QObject receiver, const QMetaMethod &method)

bool	disconnect (const QMetaObject::Connection &connection)

bool	disconnect (const QObject sender, PointerToMemberFunction signal, const QObject receiver, PointerToMemberFunction method)

Public Attributes inherited from QAbstractItemModel
typedef	CheckIndexOptions

Protected Member Functions inherited from QAbstractItemModel
void	resetInternalData ()

QModelIndex	createIndex (int row, int column, void *ptr) const const

QModelIndex	createIndex (int row, int column, quintptr id) const const

void	beginInsertRows (const QModelIndex &parent, int first, int last)

void	endInsertRows ()

void	beginRemoveRows (const QModelIndex &parent, int first, int last)

void	endRemoveRows ()

bool	beginMoveRows (const QModelIndex &sourceParent, int sourceFirst, int sourceLast, const QModelIndex &destinationParent, int destinationChild)

void	endMoveRows ()

void	beginInsertColumns (const QModelIndex &parent, int first, int last)

void	endInsertColumns ()

void	beginRemoveColumns (const QModelIndex &parent, int first, int last)

void	endRemoveColumns ()

bool	beginMoveColumns (const QModelIndex &sourceParent, int sourceFirst, int sourceLast, const QModelIndex &destinationParent, int destinationChild)

void	endMoveColumns ()

void	reset ()

void	beginResetModel ()

void	endResetModel ()

void	changePersistentIndex (const QModelIndex &from, const QModelIndex &to)

void	changePersistentIndexList (const QModelIndexList &from, const QModelIndexList &to)

QModelIndexList	persistentIndexList () const const

void	setRoleNames (const QHash< int, QByteArray > &roleNames)

Protected Member Functions inherited from QObject
QObject *	sender () const const

int	senderSignalIndex () const const

int	receivers (const char *signal) const const

bool	isSignalConnected (const QMetaMethod &signal) const const

virtual void	timerEvent (QTimerEvent *event)

virtual void	childEvent (QChildEvent *event)

virtual void	customEvent (QEvent *event)

virtual void	connectNotify (const QMetaMethod &signal)

virtual void	disconnectNotify (const QMetaMethod &signal)

Detailed Description

A passive item model for a datasync data store.

This model can be used to display the data from a DataStore as model. The model itself is typically readonly, as the data is updated automatically as the contents in the store changes. Check out the example below to see how to use it.

After creating the model, you can set the datatype it should display via setTypeId(). This will reset the model and let it load the data from it's store. The model is generic and can handle any object or gadget type. The properties of those objects/gadgets are translated to display roles, and each object/gadget is represented by one row in the model.

This makes the model easy to use with QML, as there you access data via roles, but requires additional code to display it via a QTreeView or similar. Here, another project of mine can help: QObjectListModel Provides a class called QObjectProxyModel. This class can map roles to columns, making it possible to display a model like this one in widgets properly. The example below shows how to.

To "modify" the model, use one of the datasync stores and insert, updated or remove data. Once the change is successfully done in the engine, the model updates automatically. Sorting the model itself is not possible, but you can make use of a QSortFilterProxyModel to display the data sorted.

The model is readonly by default, but you can make exising items editable via DataStoreModel::editable. This does not allow inserting or removing items via the model, but allows you to change properties via the setData() method.

Items can be loaded from the model use loadObject(). This allows you to get the item at a specific index and pass it to other components, update it and other. This method loads a new instance from the store, and this is safe in any case. With the object() method this can be done faster, but is not** safe for all types. Read the DataStoreModel::object documentation for details.

Example

Assuming your data class looks like this:

class Person
{
    Q_GADGET
    Q_PROPERTY(QString name MEMBER name)
    Q_PROPERTY(int age MEMBER age)
    //...
};

You can instanciate a model for this data as follows:

auto model = new QtDataSync::DataStoreModel(this);

model->setTypeId<Person>();

One additional feature of the model is, that it can also serve as model for table/tree views by delegating properties to multiple columns. This way you can use the model from QML by using the property names, and from widgets by delegating the properties to extra columns. For the above sample, the following code will result in a model with 2 columns, presenting the name and age properties as the Qt::DisplayRole of each column:

// setup first
auto model = new QtDataSync::DataStoreModel(this);
model->setTypeId<Person>();
// add the column config:
auto col0 = model->addColumn("Name");
model->addRole(col0, Qt::DisplayRole, "name");
// or as shortcut for the above:
model->addColumn("Age", "age");

See also: DataStore

Definition at line 13 of file datastoremodel.h.

Constructor & Destructor Documentation

◆ DataStoreModel() [1/3]

QtDataSync::DataStoreModel::DataStoreModel ( QObject * parent = nullptr )

explicit

Constructs a model for the default setup.

Parameters

parent The parent object

Exceptions

SetupDoesNotExistException Thrown if the default setup was not created yet

◆ DataStoreModel() [2/3]

QtDataSync::DataStoreModel::DataStoreModel	(	const QString &	setupName,
		QObject *	parent = `nullptr`
	)

explicit

Constructs a model for the given setup.

Parameters

setupName	The name of the setup to connect to
parent	The parent object

Exceptions

SetupDoesNotExistException Thrown if the given setup was not created yet

◆ DataStoreModel() [3/3]

QtDataSync::DataStoreModel::DataStoreModel	(	DataStore *	store,
		QObject *	parent = `nullptr`
	)

explicit

Constructs a model on the given store.

Parameters

store	The store to be used by the model
parent	The parent object

Attention: The model does not take ownership of the passed store. Thus, the store must stay valid as long as the model exists.

Member Function Documentation

◆ addColumn() [1/2]

QVariant QtDataSync::DataStoreModel::addColumn ( const QString & text )

Add a new column with the given title.

Parameters

text	The display name of the column header

Returns: The index of the newly created column

The method add a column to the model that can be used to present propeties from the underlying data as specific roles.

Attention: If no custom columns have been added yet, the model with have a single column with the typeId class name as title. By calling this method the first time, this default column will be replaced by whatever column you specify. All subsequent columns are simply added as new columns.

See also: DataStoreModel, DataStoreModel::typeId, DataStore::addRole, DataStore::clearColumns

◆ addColumn() [2/2]

QVariant QtDataSync::DataStoreModel::addColumn	(	const QString &	text,
		const char *	propertyName
	)

Add a new column and set the given property as its Qt::DisplayRole.

Parameters

text	The display name of the column header
propertyName	The name of the property to presented as the display role of that column

Returns: The index of the newly created column

This method is basically a shortcut for:

auto column = model->addColumn(text);

model->addRole(column, Qt::DisplayRole, propertyName

See also: DataStoreModel, DataStoreModel::typeId, DataStore::addRole, DataStore::clearColumns

◆ addRole()

QVariant QtDataSync::DataStoreModel::addRole	(	int	column,
		int	role,
		const char *	propertyName
	)

Adds the given property as a new role to the given column.

Parameters

column	The existing column to add the role to
role	The role that should be added to the column
propertyName	The name of the property to presented as the give role of that column

This method adds a new role to an existing column. The new role will simply the the value of the given property of the object in each row. It's basically a delegate to the properties role.

See also: DataStoreModel, DataStoreModel::typeId, DataStore::addColumn, DataStore::clearColumns

◆ loadObject() [1/2]

QVariant QtDataSync::DataStoreModel::loadObject ( const QModelIndex & index ) const

Loads the object at the given index from the store via DataStore::load.

Parameters

index The model index to return the object for

Returns: The data at the index, or a default constructed value

Exceptions

NoDataException	In case no dataset for the given type and key was found
LocalStoreException	In case of an internal error

The method uses the store() to load a new instance of the data using the very key of the dataset the given index identifies. The returned data is owned by the caller. For more details, check DataStore::load.

See also: DataStoreModel::object, DataStore::load

◆ loadObject() [2/2]

template<typename T >

T QtDataSync::DataStoreModel::loadObject ( const QModelIndex & index ) const

Loads the object at the given index from the store via DataStore::load.

Template Parameters

T	The type of object to return. Must match DataStoreModel::typeId

Parameters

index The model index to return the object for

Returns: The data at the index, or a default constructed value

Exceptions

NoDataException	In case no dataset for the given type and key was found
LocalStoreException	In case of an internal error

The method uses the store() to load a new instance of the data using the very key of the dataset the given index identifies. The returned data is owned by the caller. For more details, check DataStore::load.

See also: DataStoreModel::object, DataStore::load

Definition at line 165 of file datastoremodel.h.

◆ object() [1/2]

QVariant QtDataSync::DataStoreModel::object ( const QModelIndex & index ) const

Returns the object at the given index.

Parameters

index The model index to return the object for

Returns: The data at the index, or a default constructed value

Warning: When working with QObjects, the method is potentially dangerous, as the returned object is owend by the model, and can be deleted any time. It is fine to use the returned object in a local scope. Do not leave a local scope, or use QPointer to be able to react in case the object gets deleted. To get a copy that you own, use the loadObject() method.

See also: DataStoreModel::loadObject, DataStore::data

◆ object() [2/2]

template<typename T >

T QtDataSync::DataStoreModel::object ( const QModelIndex & index ) const

inline

Returns the object at the given index.

Template Parameters

T	The type of object to return. Must match DataStoreModel::typeId

Parameters

index The model index to return the object for

Returns: The data at the index, or a default constructed value

Warning: When working with QObjects, the method is potentially dangerous, as the returned object is owend by the model, and can be deleted any time. It is fine to use the returned object in a local scope. Do not leave a local scope, or use QPointer to be able to react in case the object gets deleted. To get a copy that you own, use the loadObject() method.

See also: DataStoreModel::loadObject, DataStore::data

Definition at line 158 of file datastoremodel.h.

◆ setupName()

QString QtDataSync::DataStoreModel::setupName ( ) const

Returns the name of the setup this class operates on.

Returns: The name of the setup

See also: QtDataSync::Setup

◆ store()

QtDataSync::DataStoreModel::store ( ) const

Returns the data store the model works on.

Returns: A reference to the internally used store

Note: Most models do own their own datastore (only not the case if the store was passed via the constructor). The most returned stores are thus deleted as soon as the model gets destroyed.

Property Documentation

◆ editable

QtDataSync::DataStoreModel::editable

readwrite

Specifies whether the model items can be edited.

Default: false

By default, the model is not editable and servers as a normal read only model. By enabeling this property, the setData() method allows modification of items. These modifications will be automatically passed to the store and thus are permanent data changes.

Accessors
READ	isEditable()
WRITE	setEditable()
NOTIFY	editableChanged()

See also: DataStoreModel::setData

Definition at line 21 of file datastoremodel.h.

◆ typeId

QtDataSync::DataStoreModel::typeId

readwrite

Holds the type the model loads data for.

Default: QMetaType::UnknownType

The type id is essential for the model, and defines what data should be loaded. When changing the property, the model resets and the loads all data from it's store for the given type, and then reacts on changes for that type.

Setting it to an unknown or invalid type will lead to errors. The type should be set before passing the model to a view or proxy model, as these need the models roles to be defined to work properly.

Accessors
READ	typeId()
WRITE	setTypeId()
NOTIFY	typeIdChanged()

See also: DataStoreModel::storeError, DataStoreModel::reload, DataStoreModel::addColumn, DataStoreModel::addRole

Definition at line 19 of file datastoremodel.h.

The documentation for this class was generated from the following files:

datastoremodel.h
datastoremodel.dox

Public Slots

Signals

Public Member Functions

Properties

Additional Inherited Members

Detailed Description

Example

Constructor & Destructor Documentation

◆ DataStoreModel() [1/3]

◆ DataStoreModel() [2/3]

◆ DataStoreModel() [3/3]

Member Function Documentation

◆ addColumn() [1/2]

◆ addColumn() [2/2]

◆ addRole()

◆ loadObject() [1/2]

◆ loadObject() [2/2]

◆ object() [1/2]

◆ object() [2/2]

◆ setupName()

◆ store()

Property Documentation

◆ editable

◆ typeId