API

Status	Action	Method
DONE	Remove	explicit DataEngine(QObject *parent , KService::Ptr service);
DONE	Add	explicit DataEngine(QObject *parent, const KPluginInfo &info);
DONE	Remove	DataEngine(QObject *parent, const QVariantList &args);
DONE	Keep	~DataEngine();
DONE	Remove?	virtual void init(); can be removed is there will be only one constructor
DONE	Keep	virtual QStringList sources() const;
DONE	Keep	virtual Service *serviceForSource(const QString &source);
DONE	Add	KPluginInfo pluginInfo() const;
DONE	Remove	QString name() const;
DONE	Remove	QString icon() const;
DONE	Remove	QString pluginName() const;
DONE	Keep	void connectSource(const QString &source, QObject *visualization, uint pollingInterval, Plasma::IntervalAlignment intervalAlignment ) const;
DONE	Keep	void connectAllSources(QObject *visualization, uint pollingInterval, Plasma::IntervalAlignment intervalAlignment) const;
DONE	Keep	void disconnectSource(const QString &source, QObject *visualization) const;
DONE	Keep	DataContainer *containerForSource(const QString &source);
DONE	Remove	DataEngine::Data query(const QString &source) const;
DONE	Keep	bool isValid() const;
DONE	Keep	bool isEmpty() const;
DONE	Keep	Package package() const;
DONE	Remove	Service* createDefaultService(QObject *parent );
DONE	Move	static QStringList listAllEngines(const QString &parentApp); -> in PluginLoader
DONE	Move	static KPluginInfo::List listEngineInfo(const QString &parentApp); -> in PluginLoader
DONE	Move	static KPluginInfo::List listEngineInfoByCategory(const QString &category, const QString &parentApp);
DONE	Keep	void sourceAdded(const QString &source);
DONE	Keep	void sourceRemoved(const QString &source);
DONE	Keep	virtual bool sourceRequestEvent(const QString &source);
DONE	Keep	virtual bool updateSourceEvent(const QString &source);
DONE	Keep	void setData(const QString &source, const QVariant &value);
DONE	Keep	void setData(const QString &source, const QString &key, const QVariant &value);
DONE	Signature	void setData(const QString &source, const Data ->QHash<QString, QVariant> &data); -> Data becomes QHash<QString, QVariant>
DONE	Keep	void removeAllData(const QString &source);
DONE	Keep	void removeData(const QString &source, const QString &key);
DONE	Keep	void addSource(DataContainer *source);
DONE	Keep	void setMinimumPollingInterval(int minimumMs);
DONE	Keep	int minimumPollingInterval() const;
DONE	Keep	void setPollingInterval(uint frequency);
DONE	Keep	void removeAllSources();
DONE	Keep	void setValid(bool valid);
DONE	Signature	SourceDict -> QHash<QString, DataContainer*> containerDict() const;
DONE	Keep	void timerEvent(QTimerEvent *event);
DONE	Remove	void setName(const QString &name);
DONE	Remove	void setIcon(const QString &icon);
DONE	Remove	void setDefaultService(const QString &serviceName);
DONE	Keep	void setStorageEnabled(const QString &source, bool store);
DONE	Move	slot void scheduleSourcesUpdated(); -> to private class
DONE	Keep	slot void removeSource(const QString &source);
DONE	Keep	slot void updateAllSources();
DONE	Keep	slot void forceImmediateUpdateOfAllVisualizations();

DataEngine functionality currently:

   * Timed updates
   * Ease of item creation and update
   * Item destruction when not used
   * Service integration

DataEngine functionality missing:

   * Introspection / self-documenting structures
   * Ability to represent as model internally

Open Questions

These questions have come up during review-review, and should be clarified to users of our API:

   * When to write a DataEngine, when to use an import? (In a world, where we have import security)
   * Add possibility to expose QObject*s in the API, much like QAIM*s
   * Why have QVariant(Map,Hash) *and* models, why not deprecate one?
   * Should we deprecate the QVariant*, now we have models?

QML Access

   * Can haz a model?

DataEngine {
public:
	QAbstractItemModel *model() const;
}

DataSource {
	engine: “keystate”
	sources: “*Button”
	fields: {“Pressed”}
}

Example of source types of twitter engine

Twitter			tweets		posting
identi.ca 1		dents		posting
identi.ca 2 		dents		posting
avatars		model { name : picture }

TwitterModel *model = new TwitterModel(“twitter account foo”); setData(“twitter account foo”, model);

bool pressedState = false; setData(“key”, “pressed”, pressedState);

DataContainer -> model, or contains a model …

What do we want?

lifecycle management
ondemand creation
keep existing API (setData, service-related stuff)
make it easy to use “3rd party models” (e.g. some akonadi model)

Current dataengines

akonadi - Akonadi PIM data engine
applicationjobs - Application job updates (via kuiserver)
apps - Information and launching of all applications in * the app menu.
calendar - Calendar data engine
comic - Online comic strips
devicenotifications - Passive device notifications for the user.
dict - Look up word meanings
executable - Run Executable Data Engine
favicons - Data Engine for getting favicons of web sites
filebrowser - Information about files and directories.
geolocation - Geolocation Data Engine
hotplug - Tracks hot-pluggable devices as they appear and disappear.
kdeobservatory - A Data Engine for acquiring consolidated data about KDE projects
keystate - Keyboard modifier and mouse buttons states
kget - No description available
kimpanel - DataEngine for Kimpanel
kremotecontrol - Data engine for kremotecontrol
ktorrent - KTorrent data engine, for getting information from KTorrent
metadata - No description available
microblog - identi.ca and twitter micro-blogging services
mixer - No description available
mouse - Mouse position and cursor
mpris2 - Provides information from and control over media players via MPRIS2
network - Network interface information
networkmanagement - Network Manager data engine
notifications - Passive visual notifications for the user.
nowplaying - Lists currently playing music
obsdataengine - DataEngine to make API Calls to the Open Build Service
ocs - No description available
openstreetmap - The OpenStreetMap data engine can be used to query things near the user.
org.kde.active.apps - Information and launching of all applications in the app menu.
org.kde.active.bookmarks - Bookmarks from Nepomuk
org.kde.active.capabilities - Provides information and services for device-specific aspects
org.kde.active.customsearch - Provides metadata for custom searches in semantic resources
org.kde.active.metadata - Provides metadata for semantic resources
org.kde.active.persons - Provides metadata for custom searches in semantic resources
org.kde.activities - Information on Plasma Activities
org.kde.alarms - List and set Akonadi Alarms
org.kde.devicecapabilities - Provides information and services for device-specific aspects
org.kde.examples.customDataContainers - A demonstration of how to subclass DataContainer
org.kde.examples.simpleEngine - A very basic DataEngine implementation
org.kde.examples.sourcesOnRequest - A DataEngine example showing how to respond to requests for source creation and updates
org.kde.konqprofiles - List and launch Konqueror profiles
org.kde.konsoleprofiles - List and launch Konsole profiles
org.kde.mobilenetworkengine - Mobile network engine
org.kde.mobileprofileengine - No description available
org.kde.plasma.dataengine.share - Engine to share content using different services
org.kde.preview - Shows previews for webpages
org.kde.printers - No description available
org.kde.printjobs - No description available
org.kde.runner - Query KRunner and execute the results
org.kde.sharelikeconnect - Provider of actions for sharing resources
parley - Vocabulary data for Plasmoids
places - Places, as seen in the file manager and in file dialogs.
potd - Data Engine for getting various online Pictures of The Day.
powermanagement - Battery, AC, sleep and PowerDevil information.
publictransport - Plasma data engine for public transport
rss - RSS News Data Engine
rtm - An engine to work with Remember the Milk.
searchlaunch - Engine to handle queries to SAL containment
soliddevice - Device data via Solid
statusnotifieritem - Engine for applications' status information, based on the Status Notifier protocol.
systemmonitor - System status information
tasks - Information and management services for all available windows.
time - Date and time by timezone
weather - Weather data from multiple online sources
workareas - Workareas Data Engine, as described in the WorkFlow Project