class QNetworkReply

The QNetworkReply class contains the data and headers for a request sent with QNetworkAccessManager . More…

Inheritance diagram of PySide6.QtNetwork.QNetworkReply

Synopsis

Methods

Virtual methods

Signals

Note

This documentation may contain snippets that were automatically translated from C++ to Python. We always welcome contributions to the snippet translation. If you see an issue with the translation, you can also let us know by creating a ticket on https:/bugreports.qt.io/projects/PYSIDE

Detailed Description

The QNetworkReply class contains the data and meta data related to a request posted with QNetworkAccessManager . Like QNetworkRequest , it contains a URL and headers (both in parsed and raw form), some information about the reply’s state and the contents of the reply itself.

QNetworkReply is a sequential-access QIODevice, which means that once data is read from the object, it is no longer kept by the device. It is therefore the application’s responsibility to keep this data if it needs to. Whenever more data is received from the network and processed, the readyRead() signal is emitted.

The downloadProgress() signal is also emitted when data is received, but the number of bytes contained in it may not represent the actual bytes received, if any transformation is done to the contents (for example, decompressing and removing the protocol overhead).

Even though QNetworkReply is a QIODevice connected to the contents of the reply, it also emits the uploadProgress() signal, which indicates the progress of the upload for operations that have such content.

Note

Do not delete the object in the slot connected to the errorOccurred() or finished() signal. Use deleteLater().

See also

QNetworkRequest QNetworkAccessManager

class NetworkError

Indicates all possible error conditions found during the processing of the request.

Constant

Description

QNetworkReply.NoError

no error condition.

Note

When the HTTP protocol returns a redirect no error will be reported. You can check if there is a redirect with the RedirectionTargetAttribute attribute.

Constant

Description

QNetworkReply.ConnectionRefusedError

the remote server refused the connection (the server is not accepting requests)

QNetworkReply.RemoteHostClosedError

the remote server closed the connection prematurely, before the entire reply was received and processed

QNetworkReply.HostNotFoundError

the remote host name was not found (invalid hostname)

QNetworkReply.TimeoutError

the connection to the remote server timed out

QNetworkReply.OperationCanceledError

the operation was canceled via calls to abort() or close() before it was finished.

QNetworkReply.SslHandshakeFailedError

the SSL/TLS handshake failed and the encrypted channel could not be established. The sslErrors() signal should have been emitted.

QNetworkReply.TemporaryNetworkFailureError

the connection was broken due to disconnection from the network, however the system has initiated roaming to another access point. The request should be resubmitted and will be processed as soon as the connection is re-established.

QNetworkReply.NetworkSessionFailedError

the connection was broken due to disconnection from the network or failure to start the network.

QNetworkReply.BackgroundRequestNotAllowedError

the background request is not currently allowed due to platform policy.

QNetworkReply.TooManyRedirectsError

while following redirects, the maximum limit was reached. The limit is by default set to 50 or as set by QNetworkRequest::setMaxRedirectsAllowed(). (This value was introduced in 5.6.)

QNetworkReply.InsecureRedirectError

while following redirects, the network access API detected a redirect from a encrypted protocol (https) to an unencrypted one (http). (This value was introduced in 5.6.)

QNetworkReply.ProxyConnectionRefusedError

the connection to the proxy server was refused (the proxy server is not accepting requests)

QNetworkReply.ProxyConnectionClosedError

the proxy server closed the connection prematurely, before the entire reply was received and processed

QNetworkReply.ProxyNotFoundError

the proxy host name was not found (invalid proxy hostname)

QNetworkReply.ProxyTimeoutError

the connection to the proxy timed out or the proxy did not reply in time to the request sent

QNetworkReply.ProxyAuthenticationRequiredError

the proxy requires authentication in order to honour the request but did not accept any credentials offered (if any)

QNetworkReply.ContentAccessDenied

the access to the remote content was denied (similar to HTTP error 403)

QNetworkReply.ContentOperationNotPermittedError

the operation requested on the remote content is not permitted

QNetworkReply.ContentNotFoundError

the remote content was not found at the server (similar to HTTP error 404)

QNetworkReply.AuthenticationRequiredError

the remote server requires authentication to serve the content but the credentials provided were not accepted (if any)

QNetworkReply.ContentReSendError

the request needed to be sent again, but this failed for example because the upload data could not be read a second time.

QNetworkReply.ContentConflictError

the request could not be completed due to a conflict with the current state of the resource.

QNetworkReply.ContentGoneError

the requested resource is no longer available at the server.

QNetworkReply.InternalServerError

the server encountered an unexpected condition which prevented it from fulfilling the request.

QNetworkReply.OperationNotImplementedError

the server does not support the functionality required to fulfill the request.

QNetworkReply.ServiceUnavailableError

the server is unable to handle the request at this time.

QNetworkReply.ProtocolUnknownError

the Network Access API cannot honor the request because the protocol is not known

QNetworkReply.ProtocolInvalidOperationError

the requested operation is invalid for this protocol

QNetworkReply.UnknownNetworkError

an unknown network-related error was detected

QNetworkReply.UnknownProxyError

an unknown proxy-related error was detected

QNetworkReply.UnknownContentError

an unknown error related to the remote content was detected

QNetworkReply.ProtocolFailure

a breakdown in protocol was detected (parsing error, invalid or unexpected responses, etc.)

QNetworkReply.UnknownServerError

an unknown error related to the server response was detected

See also

error() errorOccurred()

__init__([parent=None])
Parameters:

parent – QObject

Creates a QNetworkReply object with parent parent.

You cannot directly instantiate QNetworkReply objects. Use QNetworkAccessManager functions to do that.

abstract abort()

Aborts the operation immediately and close down any network connections still open. Uploads still in progress are also aborted.

The finished() signal will also be emitted.

See also

close() finished()

attribute(code)
Parameters:

code – Attribute

Return type:

object

Returns the attribute associated with the code code. If the attribute has not been set, it returns an invalid QVariant (type QMetaType::UnknownType).

You can expect the default values listed in Attribute to be applied to the values returned by this function.

downloadProgress(bytesReceived, bytesTotal)
Parameters:

  • bytesReceived – int

  • bytesTotal – int

This signal is emitted to indicate the progress of the download part of this network request, if there’s any. If there’s no download associated with this request, this signal will be emitted once with 0 as the value of both bytesReceived and bytesTotal.

The bytesReceived parameter indicates the number of bytes received, while bytesTotal indicates the total number of bytes expected to be downloaded. If the number of bytes to be downloaded is not known, bytesTotal will be -1.

The download is finished when bytesReceived is equal to bytesTotal. At that time, bytesTotal will not be -1.

Note that the values of both bytesReceived and bytesTotal may be different from size(), the total number of bytes obtained through read() or readAll(), or the value of the header(ContentLengthHeader). The reason for that is that there may be protocol overhead or the data may be compressed during the download.

encrypted()

This signal is emitted when an SSL/TLS session has successfully completed the initial handshake. At this point, no user data has been transmitted. The signal can be used to perform additional checks on the certificate chain, for example to notify users when the certificate for a website has changed. If the reply does not match the expected criteria then it should be aborted by calling abort() by a slot connected to this signal. The SSL configuration in use can be inspected using the sslConfiguration() method.

Internally, QNetworkAccessManager may open multiple connections to a server, in order to allow it process requests in parallel. These connections may be reused, which means that the encrypted() signal would not be emitted. This means that you are only guaranteed to receive this signal for the first connection to a site in the lifespan of the QNetworkAccessManager .

error()
Return type:

NetworkError

Returns the error that was found during the processing of this request. If no error was found, returns NoError .

See also

setError()

errorOccurred(arg__1)
Parameters:

arg__1 – NetworkError

This signal is emitted when the reply detects an error in processing. The finished() signal will probably follow, indicating that the connection is over.

The code parameter contains the code of the error that was detected. Call errorString() to obtain a textual representation of the error condition.

Note

Do not delete the object in the slot connected to this signal. Use deleteLater().

See also

error() errorString()

finished()

This signal is emitted when the reply has finished processing. After this signal is emitted, there will be no more updates to the reply’s data or metadata.

Unless close() or abort() have been called, the reply will still be opened for reading, so the data can be retrieved by calls to read() or readAll(). In particular, if no calls to read() were made as a result of readyRead(), a call to readAll() will retrieve the full contents in a QByteArray.

This signal is emitted in tandem with finished() where that signal’s reply parameter is this object.

Note

Do not delete the object in the slot connected to this signal. Use deleteLater().

You can also use isFinished() to check if a QNetworkReply has finished even before you receive the finished() signal.

hasRawHeader(headerName)
Parameters:

headerName – str

Return type:

bool

Returns true if the raw header of name headerName was sent by the remote server

Note

In Qt versions prior to 6.7, this function took QByteArray only.

See also

rawHeader()

header(header)
Parameters:

header – KnownHeaders

Return type:

object

Returns the value of the known header header, if that header was sent by the remote server. If the header was not sent, returns an invalid QVariant.

headers()
Return type:

QHttpHeaders

Returns headers that were sent by the remote server.

ignoreSslErrors()

If this function is called, SSL errors related to network connection will be ignored, including certificate validation errors.

Warning

Be sure to always let the user inspect the errors reported by the sslErrors() signal, and only call this method upon confirmation from the user that proceeding is ok. If there are unexpected errors, the reply should be aborted. Calling this method without inspecting the actual errors will most likely pose a security risk for your application. Use it with great care!

This function can be called from the slot connected to the sslErrors() signal, which indicates which errors were found.

Note

If HTTP Strict Transport Security is enabled for QNetworkAccessManager , this function has no effect.

See also

sslConfiguration() sslErrors() ignoreSslErrors()

ignoreSslErrors(errors)
Parameters:

errors – .list of QSslError

Warning

This section contains snippets that were automatically translated from C++ to Python and may contain errors.

This is an overloaded function.

If this function is called, the SSL errors given in errors will be ignored.

Note

Because most SSL errors are associated with a certificate, for most of them you must set the expected certificate this SSL error is related to. If, for instance, you want to issue a request to a server that uses a self-signed certificate, consider the following snippet:

cert = QSslCertificate.fromPath("server-certificate.pem")
error = QSslError(QSslError.SelfSignedCertificate, cert.at(0))
expectedSslErrors = QList()
expectedSslErrors.append(error)
reply = manager.get(QNetworkRequest(QUrl("https://server.tld/index.html")))
reply.ignoreSslErrors(expectedSslErrors)
# here connect signals etc.

Multiple calls to this function will replace the list of errors that were passed in previous calls. You can clear the list of errors you want to ignore by calling this function with an empty list.

Note

If HTTP Strict Transport Security is enabled for QNetworkAccessManager , this function has no effect.

See also

sslConfiguration() sslErrors() ignoreSslErrors() setStrictTransportSecurityEnabled()

ignoreSslErrorsImplementation(arg__1)
Parameters:

arg__1 – .list of QSslError

This virtual method is provided to enable overriding the behavior of ignoreSslErrors() . ignoreSslErrors() is a public wrapper for this method. errors contains the errors the user wishes ignored.

isFinished()
Return type:

bool

Returns true when the reply has finished or was aborted.

See also

isRunning()

isRunning()
Return type:

bool

Returns true when the request is still processing and the reply has not finished or was aborted yet.

See also

isFinished()

manager()
Return type:

QNetworkAccessManager

Returns the QNetworkAccessManager that was used to create this QNetworkReply object. Initially, it is also the parent object.

metaDataChanged()

This signal is emitted whenever the metadata in this reply changes. metadata is any information that is not the content (data) itself, including the network headers. In the majority of cases, the metadata will be known fully by the time the first byte of data is received. However, it is possible to receive updates of headers or other metadata during the processing of the data.

operation()
Return type:

Operation

Returns the operation that was posted for this reply.

See also

setOperation()

preSharedKeyAuthenticationRequired(authenticator)
Parameters:

authenticator – QSslPreSharedKeyAuthenticator

This signal is emitted if the SSL/TLS handshake negotiates a PSK ciphersuite, and therefore a PSK authentication is then required.

When using PSK, the client must send to the server a valid identity and a valid pre shared key, in order for the SSL handshake to continue. Applications can provide this information in a slot connected to this signal, by filling in the passed authenticator object according to their needs.

Note

Ignoring this signal, or failing to provide the required credentials, will cause the handshake to fail, and therefore the connection to be aborted.

Note

The authenticator object is owned by the reply and must not be deleted by the application.

See also

QSslPreSharedKeyAuthenticator

rawHeader(headerName)
Parameters:

headerName – str

Return type:

QByteArray

Returns the raw contents of the header headerName as sent by the remote server. If there is no such header, returns an empty byte array, which may be indistinguishable from an empty header. Use hasRawHeader() to verify if the server sent such header field.

Note

In Qt versions prior to 6.7, this function took QByteArray only.

See also

setRawHeader() hasRawHeader() header()

rawHeaderList()
Return type:

.list of QByteArray

Returns a list of headers fields that were sent by the remote server, in the order that they were sent. Duplicate headers are merged together and take place of the latter duplicate.

rawHeaderPairs()
Return type:

.list of std.pairQByteArray,QByteArray

Returns a list of raw header pairs.

readBufferSize()
Return type:

int

Returns the size of the read buffer, in bytes.

redirectAllowed()

When client code handling the redirected() signal has verified the new URL, it emits this signal to allow the redirect to go ahead. This protocol applies to network requests whose redirects policy is set to UserVerifiedRedirectPolicy

redirected(url)
Parameters:

url – QUrl

This signal is emitted if the ManualRedirectPolicy was not set in the request and the server responded with a 3xx status (specifically 301, 302, 303, 305, 307 or 308 status code) with a valid url in the location header, indicating a HTTP redirect. The url parameter contains the new redirect url as returned by the server in the location header.

See also

RedirectPolicy

request()
Return type:

QNetworkRequest

Returns the request that was posted for this reply. In special, note that the URL for the request may be different than that of the reply.

requestSent()

This signal is emitted 1 or more times when the request was sent. Useful for custom progress or timeout handling.

setAttribute(code, value)
Parameters:

Sets the attribute code to have value value. If code was previously set, it will be overridden. If value is an invalid QVariant, the attribute will be unset.

setError(errorCode, errorString)
Parameters:

Sets the error condition to be errorCode. The human-readable message is set with errorString.

Calling setError() does not emit the errorOccurred ( NetworkError ) signal.

setFinished(arg__1)
Parameters:

arg__1 – bool

Sets the reply as finished.

After having this set the replies data must not change.

setHeader(header, value)
Parameters:

Sets the known header header to be of value value. The corresponding raw form of the header will be set as well.

setHeaders(newHeaders)
Parameters:

newHeaders – QHttpHeaders

Sets newHeaders as headers in this network reply, overriding any previously set headers.

If some headers correspond to the known headers, they will be parsed and the corresponding parsed form will also be set.

setOperation(operation)
Parameters:

operation – Operation

Sets the associated operation for this object to be operation. This value will be returned by operation() .

Note

The operation should be set when this object is created and not changed again.

See also

operation() setRequest()

setRawHeader(headerName, value)
Parameters:

Sets the raw header headerName to be of value value. If headerName was previously set, it is overridden. Multiple HTTP headers of the same name are functionally equivalent to one single header with the values concatenated, separated by commas.

If headerName matches a known header, the value value will be parsed and the corresponding parsed form will also be set.

setReadBufferSize(size)
Parameters:

size – int

Sets the size of the read buffer to be size bytes. The read buffer is the buffer that holds data that is being downloaded off the network, before it is read with QIODevice::read(). Setting the buffer size to 0 will make the buffer unlimited in size.

QNetworkReply will try to stop reading from the network once this buffer is full (i.e., bytesAvailable() returns size or more), thus causing the download to throttle down as well. If the buffer is not limited in size, QNetworkReply will try to download as fast as possible from the network.

Unlike setReadBufferSize() , QNetworkReply cannot guarantee precision in the read buffer size. That is, bytesAvailable() can return more than size.

See also

readBufferSize()

setRequest(request)
Parameters:

request – QNetworkRequest

Sets the associated request for this object to be request. This value will be returned by request() .

Note

The request should be set when this object is created and not changed again.

See also

request() setOperation()

setSslConfiguration(configuration)
Parameters:

configuration – QSslConfiguration

Sets the SSL configuration for the network connection associated with this request, if possible, to be that of config.

setSslConfigurationImplementation(arg__1)
Parameters:

arg__1 – QSslConfiguration

This virtual method is provided to enable overriding the behavior of setSslConfiguration() . setSslConfiguration() is a public wrapper for this method. If you override this method use configuration to set the SSL configuration.

setUrl(url)
Parameters:

url – QUrl

Sets the URL being processed to be url. Normally, the URL matches that of the request that was posted, but for a variety of reasons it can be different (for example, a file path being made absolute or canonical).

See also

url() request() url()

setWellKnownHeader(name, value)
Parameters:

Sets the header name to be of value value. If name was previously set, it is overridden.

socketStartedConnecting()

This signal is emitted 0 or more times, when the socket is connecting, before sending the request. Useful for custom progress or timeout handling.

sslConfiguration()
Return type:

QSslConfiguration

Returns the SSL configuration and state associated with this reply, if SSL was used. It will contain the remote server’s certificate, its certificate chain leading to the Certificate Authority as well as the encryption ciphers in use.

The peer’s certificate and its certificate chain will be known by the time sslErrors() is emitted, if it’s emitted.

sslConfigurationImplementation(arg__1)
Parameters:

arg__1 – QSslConfiguration

This virtual method is provided to enable overriding the behavior of sslConfiguration() . sslConfiguration() is a public wrapper for this method. The configuration will be returned in configuration.

sslErrors(errors)
Parameters:

errors – .list of QSslError

This signal is emitted if the SSL/TLS session encountered errors during the set up, including certificate verification errors. The errors parameter contains the list of errors.

To indicate that the errors are not fatal and that the connection should proceed, the ignoreSslErrors() function should be called from the slot connected to this signal. If it is not called, the SSL session will be torn down before any data is exchanged (including the URL).

This signal can be used to display an error message to the user indicating that security may be compromised and display the SSL settings (see sslConfiguration() to obtain it). If the user decides to proceed after analyzing the remote certificate, the slot should call ignoreSslErrors() .

uploadProgress(bytesSent, bytesTotal)
Parameters:

  • bytesSent – int

  • bytesTotal – int

This signal is emitted to indicate the progress of the upload part of this network request, if there’s any. If there’s no upload associated with this request, this signal will not be emitted.

The bytesSent parameter indicates the number of bytes uploaded, while bytesTotal indicates the total number of bytes to be uploaded. If the number of bytes to be uploaded could not be determined, bytesTotal will be -1.

The upload is finished when bytesSent is equal to bytesTotal. At that time, bytesTotal will not be -1.

url()
Return type:

QUrl

Returns the URL of the content downloaded or uploaded. Note that the URL may be different from that of the original request. If redirections were enabled in the request, then this function returns the current url that the network API is accessing, i.e the url of the resource the request got redirected to.