QWebEngineDownloadRequest Class

The QWebEngineDownloadRequest class provides information about a download. More...

Header:	#include <QWebEngineDownloadRequest>
CMake:	find_package(Qt6 COMPONENTS WebEngineCore REQUIRED) target_link_libraries(mytarget PRIVATE Qt6::WebEngineCore)
qmake:	QT += webenginecore
Instantiated By:	WebEngineDownloadRequest
Inherits:	QObject

• List of all members, including inherited members

Public Types

enum	DownloadInterruptReason { NoReason, FileFailed, FileAccessDenied, FileNoSpace, FileNameTooLong, …, UserCanceled }
enum	DownloadState { DownloadRequested, DownloadInProgress, DownloadCompleted, DownloadCancelled, DownloadInterrupted }
enum	SavePageFormat { UnknownSaveFormat, SingleHtmlSaveFormat, CompleteHtmlSaveFormat, MimeHtmlSaveFormat }

Properties

• isFinished : const bool
• isPaused : const bool

Public Functions

QString	downloadDirectory() const
QString	downloadFileName() const
quint32	id() const
QWebEngineDownloadRequest::DownloadInterruptReason	interruptReason() const
QString	interruptReasonString() const
bool	isFinished() const
bool	isPaused() const
bool	isSavePageDownload() const
QString	mimeType() const
QWebEnginePage *	page() const
qint64	receivedBytes() const
QWebEngineDownloadRequest::SavePageFormat	savePageFormat() const
void	setDownloadDirectory(const QString &directory)
void	setDownloadFileName(const QString &fileName)
void	setSavePageFormat(QWebEngineDownloadRequest::SavePageFormat format)
QWebEngineDownloadRequest::DownloadState	state() const
QString	suggestedFileName() const
qint64	totalBytes() const
QUrl	url() const

Public Slots

void	accept()
void	cancel()
void	pause()
void	resume()

Signals

void	downloadDirectoryChanged()
void	downloadFileNameChanged()
void	interruptReasonChanged()
void	isFinishedChanged()
void	isPausedChanged()
void	receivedBytesChanged()
void	savePageFormatChanged()
void	stateChanged(QWebEngineDownloadRequest::DownloadState state)
void	totalBytesChanged()

Detailed Description

QWebEngineDownloadRequest models a download throughout its life cycle, starting with a pending download request and finishing with a completed download. It can be used, for example, to get information about new downloads, to monitor progress, and to pause, resume, and cancel downloads.

Downloads are usually triggered by user interaction on a web page. It is the QWebEngineProfile's responsibility to notify the application of new download requests, which it does by emitting the downloadRequested signal together with a newly created QWebEngineDownloadRequest. The application can then examine this item and decide whether to accept it or not. A signal handler must explicitly call accept() on the item for Qt WebEngine to actually start downloading and writing data to disk. If no signal handler calls accept(), then the download request will be automatically rejected and nothing will be written to disk.

Object Life Cycle

All items are guaranteed to be valid during the emission of the downloadRequested signal. If accept() is not called by any signal handler, then the item will be deleted immediately after signal emission. This means that the application must not keep references to rejected download items. It also means the application should not use a queued connection to this signal.

If accept() is called by a signal handler, then the QWebEngineProfile will take ownership of the item. However, it is safe for the application to delete the item at any time, except during the handling of the downloadRequested signal. The QWebEngineProfile being a long-lived object, it is in fact recommended that the application delete any items it is no longer interested in.

Web Page Downloads

In addition to normal file downloads, which consist simply of retrieving some raw bytes from the network and writing them to disk, Qt WebEngine also supports saving complete web pages, which involves parsing the page's HTML, downloading any dependent resources, and potentially packaging everything into a special file format (savePageFormat). To check if a download is for a file or a web page, use isSavePageDownload.

See also QWebEngineProfile, QWebEngineProfile::downloadRequested, QWebEnginePage::download, and QWebEnginePage::save.

Member Type Documentation

enum QWebEngineDownloadRequest::DownloadInterruptReason

Describes the reason why a download was interrupted:

Constant	Value	Description
QWebEngineDownloadRequest::NoReason	0	Unknown reason or not interrupted.
QWebEngineDownloadRequest::FileFailed	1	General file operation failure.
QWebEngineDownloadRequest::FileAccessDenied	2	The file cannot be written locally, due to access restrictions.
QWebEngineDownloadRequest::FileNoSpace	3	Insufficient space on the target drive.
QWebEngineDownloadRequest::FileNameTooLong	5	The directory or file name is too long.
QWebEngineDownloadRequest::FileTooLarge	6	The file size exceeds the file system limitation.
QWebEngineDownloadRequest::FileVirusInfected	7	The file is infected with a virus.
QWebEngineDownloadRequest::FileTransientError	10	Temporary problem (for example the file is in use, out of memory, or too many files are opened at once).
QWebEngineDownloadRequest::FileBlocked	11	The file was blocked due to local policy.
QWebEngineDownloadRequest::FileSecurityCheckFailed	12	An attempt to check the safety of the download failed due to unexpected reasons.
QWebEngineDownloadRequest::FileTooShort	13	An attempt was made to seek past the end of a file when opening a file (as part of resuming a previously interrupted download).
QWebEngineDownloadRequest::FileHashMismatch	14	The partial file did not match the expected hash.
QWebEngineDownloadRequest::NetworkFailed	20	General network failure.
QWebEngineDownloadRequest::NetworkTimeout	21	The network operation has timed out.
QWebEngineDownloadRequest::NetworkDisconnected	22	The network connection has been terminated.
QWebEngineDownloadRequest::NetworkServerDown	23	The server has gone down.
QWebEngineDownloadRequest::NetworkInvalidRequest	24	The network request was invalid (for example, the original or redirected URL is invalid, has an unsupported scheme, or is disallowed by policy).
QWebEngineDownloadRequest::ServerFailed	30	General server failure.
QWebEngineDownloadRequest::ServerBadContent	33	The server does not have the requested data.
QWebEngineDownloadRequest::ServerUnauthorized	34	The server did not authorize access to the resource.
QWebEngineDownloadRequest::ServerCertProblem	35	A problem with the server certificate occurred.
QWebEngineDownloadRequest::ServerForbidden	36	Access forbidden by the server.
QWebEngineDownloadRequest::ServerUnreachable	37	Unexpected server response (might indicate that the responding server may not be the intended server).
QWebEngineDownloadRequest::UserCanceled	40	The user canceled the download.

enum QWebEngineDownloadRequest::DownloadState

This enum describes the state of the download:

Constant	Value	Description
QWebEngineDownloadRequest::DownloadRequested	0	Download has been requested, but has not been accepted yet.
QWebEngineDownloadRequest::DownloadInProgress	1	Download is in progress.
QWebEngineDownloadRequest::DownloadCompleted	2	Download completed successfully.
QWebEngineDownloadRequest::DownloadCancelled	3	Download has been cancelled.
QWebEngineDownloadRequest::DownloadInterrupted	4	Download has been interrupted (by the server or because of lost connectivity).

enum QWebEngineDownloadRequest::SavePageFormat

This enum describes the format that is used to save a web page.

Constant	Value	Description
QWebEngineDownloadRequest::UnknownSaveFormat	-1	This is not a request for downloading a complete web page.
QWebEngineDownloadRequest::SingleHtmlSaveFormat	0	The page is saved as a single HTML page. Resources such as images are not saved.
QWebEngineDownloadRequest::CompleteHtmlSaveFormat	1	The page is saved as a complete HTML page, for example a directory containing the single HTML page and the resources.
QWebEngineDownloadRequest::MimeHtmlSaveFormat	2	The page is saved as a complete web page in the MIME HTML format.

Member Function Documentation

[slot] void QWebEngineDownloadRequest::accept()

Accepts the current download request, which will start the download.

If the item is in the DownloadRequested state, then it will transition into the DownloadInProgress state and the downloading will begin. If the item is in any other state, then nothing will happen.

See also isFinished and stateChanged().

[slot] void QWebEngineDownloadRequest::cancel()

Cancels the current download.

If the item is in the DownloadInProgress state, then it will transition into the DownloadCancelled state, the downloading will stop, and partially downloaded files will be deleted from disk.

If the item is in the DownloadCompleted state, then nothing will happen. If the item is in any other state, then it will transition into the DownloadCancelled state without further effect.

See also isFinished and stateChanged().

[signal] void QWebEngineDownloadRequest::isPausedChanged()

This signal is emitted whenever isPaused changes.

Note: Notifier signal for property isPaused.

See also pause() and isPaused.

[slot] void QWebEngineDownloadRequest::pause()

Pauses the download.

Has no effect if the state is not DownloadInProgress. Does not change the state.

See also resume() and isPaused().

[slot] void QWebEngineDownloadRequest::resume()

Resumes the current download if it was paused or interrupted.

Has no effect if the state is not DownloadInProgress or DownloadInterrupted. Does not change the state.

See also pause(), isPaused(), and state().

[signal] void QWebEngineDownloadRequest::stateChanged(QWebEngineDownloadRequest::DownloadState state)

This signal is emitted whenever the download's state changes.

Note: Notifier signal for property state.

See also state() and DownloadState.

QString QWebEngineDownloadRequest::downloadDirectory() const

Returns the download directory path.

Note: Getter function for property downloadDirectory.

See also setDownloadDirectory().

QString QWebEngineDownloadRequest::downloadFileName() const

Returns the file name to download the file to.

Note: Getter function for property downloadFileName.

See also setDownloadFileName().

quint32 QWebEngineDownloadRequest::id() const

Returns the download item's ID.

Note: Getter function for property id.

QWebEngineDownloadRequest::DownloadInterruptReason QWebEngineDownloadRequest::interruptReason() const

Returns the reason why the download was interrupted.

Note: Getter function for property interruptReason.

See also interruptReasonString().

QString QWebEngineDownloadRequest::interruptReasonString() const

Returns a human-readable description of the reason for interrupting the download.

Note: Getter function for property interruptReasonString.

See also interruptReason().

bool QWebEngineDownloadRequest::isSavePageDownload() const

Returns true if this is a download request for saving a web page.

Note: Getter function for property isSavePageDownload.

See also savePageFormat() and setSavePageFormat().

QString QWebEngineDownloadRequest::mimeType() const

Returns the MIME type of the download.

Note: Getter function for property mimeType.

QWebEnginePage *QWebEngineDownloadRequest::page() const

Returns the page the download was requested on. If the download was not triggered by content in a page, nullptr is returned.

qint64 QWebEngineDownloadRequest::receivedBytes() const

Returns the amount of data in bytes that has been downloaded so far.

-1 means the size is unknown.

Note: Getter function for property receivedBytes.

QWebEngineDownloadRequest::SavePageFormat QWebEngineDownloadRequest::savePageFormat() const

Returns the format the web page will be saved in if this is a download request for a web page.

Note: Getter function for property savePageFormat.

See also setSavePageFormat() and isSavePageDownload().

void QWebEngineDownloadRequest::setDownloadDirectory(const QString &directory)

Sets directory as the directory path to download the file to.

The download directory path can only be set in response to the QWebEngineProfile::downloadRequested() signal before the download is accepted. Past that point, this function has no effect on the download item's state.

Note: Setter function for property downloadDirectory.

See also downloadDirectory().

void QWebEngineDownloadRequest::setDownloadFileName(const QString &fileName)

Sets fileName as the file name to download the file to.

The download file name can only be set in response to the QWebEngineProfile::downloadRequested() signal before the download is accepted. Past that point, this function has no effect on the download item's state.

Note: Setter function for property downloadFileName.

See also downloadFileName().

void QWebEngineDownloadRequest::setSavePageFormat(QWebEngineDownloadRequest::SavePageFormat format)

Sets the format the web page will be saved in if this is a download request for a web page.

Note: Setter function for property savePageFormat.

See also savePageFormat() and isSavePageDownload().

QWebEngineDownloadRequest::DownloadState QWebEngineDownloadRequest::state() const

Returns the download item's current state.

Note: Getter function for property state.

See also DownloadState.

QString QWebEngineDownloadRequest::suggestedFileName() const

Returns the suggested file name.

Note: Getter function for property suggestedFileName.

qint64 QWebEngineDownloadRequest::totalBytes() const

Returns the the total amount of data to download in bytes.

-1 means the size is unknown.

Note: Getter function for property totalBytes.

QUrl QWebEngineDownloadRequest::url() const

Returns the download's origin URL.

Note: Getter function for property url.