QHelpEngineCore

The QHelpEngineCore class provides the core functionality of the help system. More…

Inheritance diagram of PySide2.QtHelp.QHelpEngineCore

Inherited by: QHelpEngine

Synopsis

Functions

Signals

Static functions

Detailed Description

Before the help engine can be used, it must be initialized by calling setupData() . At the beginning of the setup process the signal setupStarted() is emitted. From this point on until the signal setupFinished() is emitted, is the help data in an undefined meaning unusable state.

The core help engine can be used to perform different tasks. By calling documentsForIdentifier() the engine returns URLs specifying the file locations inside the help system. The actual file data can then be retrived by calling fileData() .

The help engine can contain any number of custom filters. The management of the filters, including adding new filters, changing filter definitions, or removing existing filters, is done through the QHelpFilterEngine class, which can be accessed by the filterEngine() method.

Note

QHelpFilterEngine replaces the older filter API that is deprecated since Qt 5.13. Call setUsesFilterEngine() with true to enable the new functionality.

The help engine also offers the possibility to set and read values in a persistent way comparable to ini files or Windows registry entries. For more information see or value().

This class does not offer any GUI components or functionality for indices or contents. If you need one of those use QHelpEngine instead.

When creating a custom help viewer the viewer can be configured by writing a custom collection file which could contain various keywords to be used to configure the help engine. These keywords and values and their meaning can be found in the help information for creating a custom help collection file for Assistant.

class PySide2.QtHelp.QHelpEngineCore(collectionFile[, parent=None])
param parent:

PySide2.QtCore.QObject

param collectionFile:

str

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.

PySide2.QtHelp.QHelpEngineCore.addCustomFilter(filterName, attributes)
Parameters:

  • filterName – str

  • attributes – list of strings

Return type:

bool

setFilterData() should be used instead.

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() removeCustomFilter()

PySide2.QtHelp.QHelpEngineCore.autoSaveFilter()
Return type:

bool

This property holds whether QHelpEngineCore is in auto save filter mode or not..

If QHelpEngineCore is in auto save filter mode, the current filter is automatically saved when it is changed by the setActiveFilter() function. The filter is saved persistently in the help collection file.

By default, this mode is on.

PySide2.QtHelp.QHelpEngineCore.collectionFile()
Return type:

str

This property holds the absolute file name of the collection file currently used..

Setting this property leaves the help engine in an invalid state. It is important to invoke setupData() or any getter function in order to setup the help engine again.

PySide2.QtHelp.QHelpEngineCore.copyCollectionFile(fileName)
Parameters:

fileName – str

Return type:

bool

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.

PySide2.QtHelp.QHelpEngineCore.currentFilter()
Return type:

str

This property holds the name of the custom filter currently applied..

activeFilter() should be used instead.

Setting this property will save the new custom filter permanently in the help collection file. To set a custom filter without saving it permanently, disable the auto save filter mode.

See also

autoSaveFilter()

PySide2.QtHelp.QHelpEngineCore.currentFilterChanged(newFilter)
Parameters:

newFilter – str

PySide2.QtHelp.QHelpEngineCore.customFilters()
Return type:

list of strings

filters() should be used instead.

Returns a list of custom filters.

See also

addCustomFilter() removeCustomFilter()

PySide2.QtHelp.QHelpEngineCore.customValue(key[, defaultValue=None])
Parameters:

  • key – str

  • defaultValue – object

Return type:

object

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

See also

setCustomValue() removeCustomValue()

PySide2.QtHelp.QHelpEngineCore.documentationFileName(namespaceName)
Parameters:

namespaceName – str

Return type:

str

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()

PySide2.QtHelp.QHelpEngineCore.documentsForIdentifier(id)
Parameters:

id – str

Return type:

Returns a list of all the document links found for the id . The returned list contents depend on the current filter, and therefore only the keywords registered for the current filter will be returned.

PySide2.QtHelp.QHelpEngineCore.documentsForIdentifier(id, filterName)
Parameters:

  • id – str

  • filterName – str

Return type:

Returns a list of the document links found for the id , filtered by filterName . The returned list contents depend on the passed filter, and therefore only the keywords registered for this filter will be returned. If you want to get all results unfiltered, pass empty string as filterName .

PySide2.QtHelp.QHelpEngineCore.documentsForKeyword(keyword)
Parameters:

keyword – str

Return type:

Returns a list of all the document links found for the keyword . The returned list contents depend on the current filter, and therefore only the keywords registered for the current filter will be returned.

PySide2.QtHelp.QHelpEngineCore.documentsForKeyword(keyword, filterName)
Parameters:

  • keyword – str

  • filterName – str

Return type:

Returns a list of the document links found for the keyword , filtered by filterName . The returned list contents depend on the passed filter, and therefore only the keywords registered for this filter will be returned. If you want to get all results unfiltered, pass empty string as filterName .

PySide2.QtHelp.QHelpEngineCore.error()
Return type:

str

Returns a description of the last error that occurred.

PySide2.QtHelp.QHelpEngineCore.fileData(url)
Parameters:

url – PySide2.QtCore.QUrl

Return type:

PySide2.QtCore.QByteArray

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

See also

findFile()

PySide2.QtHelp.QHelpEngineCore.files(namespaceName, filterName[, extensionFilter=""])
Parameters:

  • namespaceName – str

  • filterName – str

  • extensionFilter – str

Return type:

PySide2.QtHelp.QHelpEngineCore.files(namespaceName, filterAttributes[, extensionFilter=""])
Parameters:

  • namespaceName – str

  • filterAttributes – list of strings

  • extensionFilter – str

Return type:

PySide2.QtHelp.QHelpEngineCore.filterAttributeSets(namespaceName)
Parameters:

namespaceName – str

Return type:

filterData() should be used instead.

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

PySide2.QtHelp.QHelpEngineCore.filterAttributes()
Return type:

list of strings

availableComponents() should be used instead.

Returns a list of all defined filter attributes.

PySide2.QtHelp.QHelpEngineCore.filterAttributes(filterName)
Parameters:

filterName – str

Return type:

list of strings

filterData() should be used instead.

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

PySide2.QtHelp.QHelpEngineCore.filterEngine()
Return type:

PySide2.QtHelp.QHelpFilterEngine

Returns the filter engine associated with this help engine. The filter engine allows for adding, changing, and removing existing filters for this help engine. To use the engine you also have to call setUsesFilterEngine() set to true .

PySide2.QtHelp.QHelpEngineCore.findFile(url)
Parameters:

url – PySide2.QtCore.QUrl

Return type:

PySide2.QtCore.QUrl

Returns the corrected URL for the url that may refer to a different namespace defined by the virtual folder defined as a part of the url . If the virtual folder matches the namespace of the url , the method just checks if the file exists and returns the same url . When the virtual folder doesn’t match the namespace of the url , it tries to find the best matching namespace according to the active filter. When the namespace is found, it returns the corrected URL if the file exists, otherwise it returns an invalid URL.

PySide2.QtHelp.QHelpEngineCore.linksForIdentifier(id)
Parameters:

id – str

Return type:

Note

This function is deprecated.

Use documentsForIdentifier() instead.

Returns a map of the documents found for the id . The map contains the document titles and their URLs. The returned map contents depend on the current filter, and therefore only the identifiers registered for the current filter will be returned.

PySide2.QtHelp.QHelpEngineCore.linksForKeyword(keyword)
Parameters:

keyword – str

Return type:

Note

This function is deprecated.

Use documentsForKeyword() instead.

Returns a map of all the documents found for the keyword . The map contains the document titles and URLs. The returned map contents depend on the current filter, and therefore only the keywords registered for the current filter will be returned.

static PySide2.QtHelp.QHelpEngineCore.metaData(documentationFileName, name)
Parameters:

  • documentationFileName – str

  • name – str

Return type:

object

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 PySide2.QtHelp.QHelpEngineCore.namespaceName(documentationFileName)
Parameters:

documentationFileName – str

Return type:

str

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()

PySide2.QtHelp.QHelpEngineCore.readersAboutToBeInvalidated()
PySide2.QtHelp.QHelpEngineCore.registerDocumentation(documentationFileName)
Parameters:

documentationFileName – str

Return type:

bool

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() error()

PySide2.QtHelp.QHelpEngineCore.registeredDocumentations()
Return type:

list of strings

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).

PySide2.QtHelp.QHelpEngineCore.removeCustomFilter(filterName)
Parameters:

filterName – str

Return type:

bool

removeFilter() should be used instead.

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

See also

addCustomFilter() customFilters()

PySide2.QtHelp.QHelpEngineCore.removeCustomValue(key)
Parameters:

key – str

Return type:

bool

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

See also

customValue() setCustomValue()

PySide2.QtHelp.QHelpEngineCore.setAutoSaveFilter(save)
Parameters:

save – bool

This property holds whether QHelpEngineCore is in auto save filter mode or not..

If QHelpEngineCore is in auto save filter mode, the current filter is automatically saved when it is changed by the setActiveFilter() function. The filter is saved persistently in the help collection file.

By default, this mode is on.

PySide2.QtHelp.QHelpEngineCore.setCollectionFile(fileName)
Parameters:

fileName – str

This property holds the absolute file name of the collection file currently used..

Setting this property leaves the help engine in an invalid state. It is important to invoke setupData() or any getter function in order to setup the help engine again.

PySide2.QtHelp.QHelpEngineCore.setCurrentFilter(filterName)
Parameters:

filterName – str

This property holds the name of the custom filter currently applied..

activeFilter() should be used instead.

Setting this property will save the new custom filter permanently in the help collection file. To set a custom filter without saving it permanently, disable the auto save filter mode.

See also

autoSaveFilter()

PySide2.QtHelp.QHelpEngineCore.setCustomValue(key, value)
Parameters:

  • key – str

  • value – object

Return type:

bool

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() removeCustomValue()

PySide2.QtHelp.QHelpEngineCore.setUsesFilterEngine(uses)
Parameters:

uses – bool

Enables or disables the new filter engine functionality inside the help engine, according to the passed uses parameter.

See also

usesFilterEngine() filterEngine()

PySide2.QtHelp.QHelpEngineCore.setupData()
Return type:

bool

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.

PySide2.QtHelp.QHelpEngineCore.setupFinished()
PySide2.QtHelp.QHelpEngineCore.setupStarted()
PySide2.QtHelp.QHelpEngineCore.unregisterDocumentation(namespaceName)
Parameters:

namespaceName – str

Return type:

bool

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

See also

registerDocumentation() error()

PySide2.QtHelp.QHelpEngineCore.usesFilterEngine()
Return type:

bool

Returns whether the help engine uses the new filter functionality.

See also

setUsesFilterEngine() filterEngine()

PySide2.QtHelp.QHelpEngineCore.warning(msg)
Parameters:

msg – str