Handles HTTP network content fetching in a background task. More...

#include <qgsnetworkcontentfetchertask.h>

Inheritance diagram for QgsNetworkContentFetcherTask:

[legend]

Signals
void	errorOccurred (QNetworkReply::NetworkError code, const QString &errorMsg)
	Emitted when an error with code error occurred while processing the request errorMsg is a textual description of the error.

void	fetched ()
	Emitted when the network content has been fetched, regardless of whether the fetch was successful or not.

Signals inherited from QgsTask
void	begun ()
	Will be emitted by task to indicate its commencement.

void	progressChanged (double progress)
	Will be emitted by task when its progress changes.

void	statusChanged (int status)
	Will be emitted by task when its status changes.

void	taskCompleted ()
	Will be emitted by task to indicate its successful completion.

void	taskTerminated ()
	Will be emitted by task if it has terminated for any reason other then completion (e.g., when a task has been canceled or encountered an internal error).

Public Member Functions
	QgsNetworkContentFetcherTask (const QNetworkRequest &request, const QString &authcfg=QString(), QgsTask::Flags flags=QgsTask::CanCancel, const QString &description=QString())
	Constructor for a QgsNetworkContentFetcherTask which fetches the specified network request.

	QgsNetworkContentFetcherTask (const QUrl &url, const QString &authcfg=QString(), QgsTask::Flags flags=QgsTask::CanCancel, const QString &description=QString())
	Constructor for a QgsNetworkContentFetcherTask which fetches the specified url.

	~QgsNetworkContentFetcherTask () override

void	cancel () override
	Notifies the task that it should terminate.

QString	contentAsString () const
	Returns the fetched content as a string.

QString	contentDispositionFilename () const
	Returns the associated filename from the reply's content disposition header, if present.

QNetworkReply *	reply ()
	Returns the network reply.

bool	run () override
	Performs the task's operation.

Public Member Functions inherited from QgsTask
	QgsTask (const QString &description=QString(), QgsTask::Flags flags=AllFlags)
	Constructor for QgsTask.

	~QgsTask () override

void	addSubTask (QgsTask *subTask, const QgsTaskList &dependencies=QgsTaskList(), SubTaskDependency subTaskDependency=SubTaskIndependent)
	Adds a subtask to this task.

bool	canCancel () const
	Returns `true` if the task can be canceled.

QList< QgsMapLayer * >	dependentLayers () const
	Returns the list of layers on which the task depends.

QString	description () const
	Returns the task's description.

qint64	elapsedTime () const
	Returns the elapsed time since the task commenced, in milliseconds.

Flags	flags () const
	Returns the flags associated with the task.

void	hold ()
	Places the task on hold.

bool	isActive () const
	Returns `true` if the task is active, ie it is not complete and has not been canceled.

double	progress () const
	Returns the task's progress (between 0.0 and 100.0)

void	setDependentLayers (const QList< QgsMapLayer * > &dependentLayers)
	Sets a list of layers on which the task depends.

void	setDescription (const QString &description)
	Sets the task's description.

TaskStatus	status () const
	Returns the current task status.

void	unhold ()
	Releases the task from being held.

bool	waitForFinished (int timeout=30000)
	Blocks the current thread until the task finishes or a maximum of timeout milliseconds.

Additional Inherited Members
Public Types inherited from QgsTask
enum	Flag { CanCancel = 1 << 1 , CancelWithoutPrompt = 1 << 2 , Hidden = 1 << 3 , Silent = 1 << 4 , AllFlags = CanCancel }
	Task flags. More...

typedef QFlags< Flag >	Flags

enum	SubTaskDependency { SubTaskIndependent = 0 , ParentDependsOnSubTask }
	Controls how subtasks relate to their parent task. More...

enum	TaskStatus { Queued , OnHold , Running , Complete , Terminated }
	Status of tasks. More...

Protected Slots inherited from QgsTask
void	setProgress (double progress)
	Sets the task's current progress.

Protected Member Functions inherited from QgsTask
virtual void	finished (bool result)
	If the task is managed by a QgsTaskManager, this will be called after the task has finished (whether through successful completion or via early termination).

bool	isCanceled () const
	Will return `true` if task should terminate ASAP.

Detailed Description

Handles HTTP network content fetching in a background task.

Provides a simple method for fetching remote HTTP content in a QgsTask. Url redirects are automatically handled.

After constructing a QgsNetworkContentFetcherTask, callers should connect to the QgsNetworkContentFetcherTask::fetched signal. They can then safely access the network reply() from the connected slot without danger of the task being first removed by the QgsTaskManager.

See also: QgsNetworkContentFetcher

Since: QGIS 3.2

Definition at line 47 of file qgsnetworkcontentfetchertask.h.

Constructor & Destructor Documentation

◆ QgsNetworkContentFetcherTask() [1/2]

QgsNetworkContentFetcherTask::QgsNetworkContentFetcherTask	(	const QUrl &	url,
		const QString &	authcfg = `QString()`,
		QgsTask::Flags	flags = `QgsTask::CanCancel`,
		const QString &	description = `QString()`
	)

Constructor for a QgsNetworkContentFetcherTask which fetches the specified url.

Optionally, authentication configuration can be set via the authcfg argument.

Since QGIS 3.28 the optional description can be explicitly set. If not specified, a default task description will be generated.

Definition at line 25 of file qgsnetworkcontentfetchertask.cpp.

◆ QgsNetworkContentFetcherTask() [2/2]

QgsNetworkContentFetcherTask::QgsNetworkContentFetcherTask	(	const QNetworkRequest &	request,
		const QString &	authcfg = `QString()`,
		QgsTask::Flags	flags = `QgsTask::CanCancel`,
		const QString &	description = `QString()`
	)

Constructor for a QgsNetworkContentFetcherTask which fetches the specified network request.

Optionally, authentication configuration can be set via the authcfg argument.

Since QGIS 3.28 the optional description can be explicitly set. If not specified, a default task description will be generated.

Definition at line 30 of file qgsnetworkcontentfetchertask.cpp.

◆ ~QgsNetworkContentFetcherTask()

QgsNetworkContentFetcherTask::~QgsNetworkContentFetcherTask ( )

override

Definition at line 37 of file qgsnetworkcontentfetchertask.cpp.

Member Function Documentation

◆ cancel()

void QgsNetworkContentFetcherTask::cancel ( )

overridevirtual

Notifies the task that it should terminate.

Calling this is not guaranteed to immediately end the task, rather it sets the isCanceled() flag which task subclasses can check and terminate their operations at an appropriate time. Any subtasks owned by this task will also be canceled. Derived classes must ensure that the base class implementation is called from any overridden version.

See also: isCanceled()

Reimplemented from QgsTask.

Definition at line 82 of file qgsnetworkcontentfetchertask.cpp.

◆ contentAsString()

QString QgsNetworkContentFetcherTask::contentAsString ( ) const

Returns the fetched content as a string.

Warning: This should only be accessed from a slot connected directly to the QgsNetworkContentFetcherTask::fetched() signal.

Since: QGIS 3.10

Definition at line 100 of file qgsnetworkcontentfetchertask.cpp.

◆ contentDispositionFilename()

QString QgsNetworkContentFetcherTask::contentDispositionFilename ( ) const

Returns the associated filename from the reply's content disposition header, if present.

Since: QGIS 3.28

Definition at line 95 of file qgsnetworkcontentfetchertask.cpp.

◆ errorOccurred

void QgsNetworkContentFetcherTask::errorOccurred	(	QNetworkReply::NetworkError	code,
		const QString &	errorMsg
	)

signal

Emitted when an error with code error occurred while processing the request errorMsg is a textual description of the error.

Since: QGIS 3.22

◆ fetched

void QgsNetworkContentFetcherTask::fetched ( )

signal

Emitted when the network content has been fetched, regardless of whether the fetch was successful or not.

Users of QgsNetworkContentFetcherTask should connect to this signal, and from the associated slot they can then safely access the network reply() without danger of the task being first removed by the QgsTaskManager.

◆ reply()

QNetworkReply * QgsNetworkContentFetcherTask::reply ( )

Returns the network reply.

Ownership is not transferred.

May return nullptr if the request has not yet completed.

Warning: This should only be accessed from a slot connected directly to the QgsNetworkContentFetcherTask::fetched() signal.

Definition at line 90 of file qgsnetworkcontentfetchertask.cpp.

◆ run()

bool QgsNetworkContentFetcherTask::run ( )

overridevirtual

Performs the task's operation.

This method will be called when the task commences (ie via calling start() ), and subclasses should implement the operation they wish to perform in the background within this method.

A task must return a boolean value to indicate whether the task was completed successfully or terminated before completion.

Implements QgsTask.

Definition at line 43 of file qgsnetworkcontentfetchertask.cpp.

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

/build/qgis-3.41.0+git20241119+45a0abf3bec+99sid/src/core/network/qgsnetworkcontentfetchertask.h
/build/qgis-3.41.0+git20241119+45a0abf3bec+99sid/src/core/network/qgsnetworkcontentfetchertask.cpp

Signals

Public Member Functions

Additional Inherited Members