QHelpEngineCore Class

Member Function Documentation

QHelpEngineCore::QHelpEngineCore(const QString &collectionFile, QObject *parent = nullptr)

Constructs a new core help engine with a parent. The help engine uses the information stored in the collectionFile to provide help. If the collection file does not exist yet, it'll be created.

[virtual] QHelpEngineCore::~QHelpEngineCore()

Destructs the help engine.

bool QHelpEngineCore::addCustomFilter(const QString &filterName, const QStringList &attributes)

Adds the new custom filter filterName. The filter attributes are specified by attributes. If the filter already exists, its attribute set is replaced. The function returns true if the operation succeeded, otherwise it returns false.

See also customFilters() and removeCustomFilter().

bool QHelpEngineCore::copyCollectionFile(const QString &fileName)

Creates the file fileName and copies all contents from the current collection file into the newly created file, and returns true if successful; otherwise returns false.

The copying process makes sure that file references to Qt Collection files (.qch) files are updated accordingly.

[signal] void QHelpEngineCore::currentFilterChanged(const QString &newFilter)

This signal is emitted when the current filter is changed to newFilter.

QStringList QHelpEngineCore::customFilters() const

Returns a list of custom filters.

See also addCustomFilter() and removeCustomFilter().

QVariant QHelpEngineCore::customValue(const QString &key, const QVariant &defaultValue = QVariant()) const

Returns the value assigned to the key. If the requested key does not exist, the specified defaultValue is returned.

See also setCustomValue() and removeCustomValue().

QString QHelpEngineCore::documentationFileName(const QString &namespaceName)

Returns the absolute file name of the Qt compressed help file (.qch) identified by the namespaceName. If there is no Qt compressed help file with the specified namespace registered, an empty string is returned.

See also namespaceName().

QString QHelpEngineCore::error() const

Returns a description of the last error that occurred.

QByteArray QHelpEngineCore::fileData(const QUrl &url) const

Returns the data of the file specified by url. If the file does not exist, an empty QByteArray is returned.

See also findFile().

QList<QUrl> QHelpEngineCore::files(const QString namespaceName, const QStringList &filterAttributes, const QString &extensionFilter = QString())

Returns a list of files contained in the Qt compressed help file namespaceName. The files can be filtered by filterAttributes as well as by their extension extensionFilter (e.g. 'html').

QList<QStringList> QHelpEngineCore::filterAttributeSets(const QString &namespaceName) const

Returns a list of filter attributes for the different filter sections defined in the Qt compressed help file with the given namespace namespaceName.

QStringList QHelpEngineCore::filterAttributes() const

Returns a list of all defined filter attributes.

QStringList QHelpEngineCore::filterAttributes(const QString &filterName) const

Returns a list of filter attributes used by the custom filter filterName.

QUrl QHelpEngineCore::findFile(const QUrl &url) const

Returns an invalid URL if the file url cannot be found. If the file exists, either the same url is returned or a different url if the file is located in a different namespace which is merged via a common virtual folder.

QMap<QString, QUrl> QHelpEngineCore::linksForIdentifier(const QString &id) const

Returns documents found for the id. The map contains the document titles and their URLs. The returned map contents depends on the current filter, meaning only the keywords registered for the current filter will be returned.

QMap<QString, QUrl> QHelpEngineCore::linksForKeyword(const QString &keyword) const

Returns all documents found for the keyword. The returned map consists of the document titles and their URLs.

This function was introduced in Qt 4.5.

[static] QVariant QHelpEngineCore::metaData(const QString &documentationFileName, const QString &name)

Returns the meta data for the Qt compressed help file documentationFileName. If there is no data available for name, an invalid QVariant() is returned. The meta data is defined when creating the Qt compressed help file and cannot be modified later. Common meta data includes e.g. the author of the documentation.

[static] QString QHelpEngineCore::namespaceName(const QString &documentationFileName)

Returns the namespace name defined for the Qt compressed help file (.qch) specified by its documentationFileName. If the file is not valid, an empty string is returned.

See also documentationFileName().

[signal] void QHelpEngineCore::readersAboutToBeInvalidated()

bool QHelpEngineCore::registerDocumentation(const QString &documentationFileName)

Registers the Qt compressed help file (.qch) contained in the file documentationFileName. One compressed help file, uniquely identified by its namespace can only be registered once. True is returned if the registration was successful, otherwise false.

See also unregisterDocumentation() and error().

QStringList QHelpEngineCore::registeredDocumentations() const

Returns a list of all registered Qt compressed help files of the current collection file. The returned names are the namespaces of the registered Qt compressed help files (.qch).

bool QHelpEngineCore::removeCustomFilter(const QString &filterName)

Returns true if the filter filterName was removed successfully, otherwise false.

See also addCustomFilter() and customFilters().

bool QHelpEngineCore::removeCustomValue(const QString &key)

Removes the key from the settings section in the collection file. Returns true if the value was removed successfully, otherwise false.

See also customValue() and setCustomValue().

bool QHelpEngineCore::setCustomValue(const QString &key, const QVariant &value)

Save the value under the key. If the key already exist, the value will be overwritten. Returns true if the value was saved successfully, otherwise false.

See also customValue() and removeCustomValue().

bool QHelpEngineCore::setupData()

Sets up the help engine by processing the information found in the collection file and returns true if successful; otherwise returns false.

By calling the function, the help engine is forced to initialize itself immediately. Most of the times, this function does not have to be called explicitly because getter functions which depend on a correctly set up help engine do that themselves.

Note: qsqlite4.dll needs to be deployed with the application as the help system uses the sqlite driver when loading help collections.

[signal] void QHelpEngineCore::setupFinished()

This signal is emitted when the setup is complete.

[signal] void QHelpEngineCore::setupStarted()

This signal is emitted when setup is started.

bool QHelpEngineCore::unregisterDocumentation(const QString &namespaceName)

Unregisters the Qt compressed help file (.qch) identified by its namespaceName from the help collection. Returns true on success, otherwise false.

See also registerDocumentation() and error().

[signal] void QHelpEngineCore::warning(const QString &msg)

This signal is emitted when a non critical error occurs. The warning message is stored in msg.