QNetworkRequest Class | Qt Network 5.6

Qt 5.6 | Qt Network | C++ Classes | QNetworkRequest

Qt 5.6.2 Reference Documentation

# QNetworkRequest Class

The QNetworkRequest class holds a request to be sent with QNetworkAccessManager. More...

Header: | #include <QNetworkRequest>
qmake: | QT += network
Since: | Qt 4.4

- List of all members, including inherited members

## Public Types

enum | Attribute { HttpStatusCodeAttribute, HttpReasonPhraseAttribute, RedirectionTargetAttribute, ConnectionEncryptedAttribute, ..., UserMax }
enum | CacheLoadControl { AlwaysNetwork, PreferNetwork, PreferCache, AlwaysCache }
enum | KnownHeaders { ContentDispositionHeader, ContentTypeHeader, ContentLengthHeader, LocationHeader, ..., ServerHeader }
enum | LoadControl { Automatic, Manual }
enum | Priority { HighPriority, NormalPriority, LowPriority }

## Public Functions

| QNetworkRequest(const QUrl &url = QUrl())
| QNetworkRequest(const QNetworkRequest &other)
| ~QNetworkRequest()
QVariant | attribute(Attribute code, const QVariant &defaultValue = QVariant()) const
bool | hasRawHeader(const QByteArray &headerName) const
QVariant | header(KnownHeaders header) const
int | maximumRedirectsAllowed() const
QObject * | originatingObject() const
Priority | priority() const
QByteArray | rawHeader(const QByteArray &headerName) const
QList<QByteArray> | rawHeaderList() const
void | setAttribute(Attribute code, const QVariant &value)
void | setHeader(KnownHeaders header, const QVariant &value)
void | setMaximumRedirectsAllowed(int maxRedirectsAllowed)
void | setOriginatingObject(QObject *object)
void | setPriority(Priority priority)
void | setRawHeader(const QByteArray &headerName, const QByteArray &headerValue)
void | setSslConfiguration(const QSslConfiguration &config)
void | setUrl(const QUrl &url)
QSslConfiguration | sslConfiguration() const
void | swap(QNetworkRequest &other)
QUrl | url() const
bool | operator!=(const QNetworkRequest &other) const
QNetworkRequest & | operator=(QNetworkRequest &&other)
QNetworkRequest & | operator=(const QNetworkRequest &other)
bool | operator==(const QNetworkRequest &other) const

## Detailed Description

The QNetworkRequest class holds a request to be sent with QNetworkAccessManager.

QNetworkRequest is part of the Network Access API and is the class holding the information necessary to send a request over the network. It contains a URL and some ancillary information that can be used to modify the request.

See also QNetworkReply and QNetworkAccessManager.

## Member Type Documentation

### enum QNetworkRequest::Attribute

Attribute codes for the QNetworkRequest and QNetworkReply.

Attributes are extra meta-data that are used to control the behavior of the request and to pass further information from the reply back to the application. Attributes are also extensible, allowing custom implementations to pass custom values.

The following table explains what the default attribute codes are, the QVariant types associated, the default value if said attribute is missing and whether it's used in requests or replies.

Constant | Value | Description
--- | --- | ---
`QNetworkRequest::HttpStatusCodeAttribute` | `0` | Replies only, type: QMetaType::Int (no default) Indicates the HTTP status code received from the HTTP server (like 200, 304, 404, 401, etc.). If the connection was not HTTP-based, this attribute will not be present.
`QNetworkRequest::HttpReasonPhraseAttribute` | `1` | Replies only, type: QMetaType::QByteArray (no default) Indicates the HTTP reason phrase as received from the HTTP server (like "Ok", "Found", "Not Found", "Access Denied", etc.) This is the human-readable representation of the status code (see above). If the connection was not HTTP-based, this attribute will not be present.
`QNetworkRequest::RedirectionTargetAttribute` | `2` | Replies only, type: QMetaType::QUrl (no default) If present, it indicates that the server is redirecting the request to a different URL. The Network Access API does not by default follow redirections: the application can determine if the requested redirection should be allowed, according to its security policies, or it can set QNetworkRequest::FollowRedirectsAttribute to true (in which case the redirection will be followed and this attribute will not be present in the reply). The returned URL might be relative. Use QUrl::resolved() to create an absolute URL out of it.
`QNetworkRequest::ConnectionEncryptedAttribute` | `3` | Replies only, type: QMetaType::Bool (default: false) Indicates whether the data was obtained through an encrypted (secure) connection.
`QNetworkRequest::CacheLoadControlAttribute` | `4` | Requests only, type: QMetaType::Int (default: QNetworkRequest::PreferNetwork) Controls how the cache should be accessed. The possible values are those of QNetworkRequest::CacheLoadControl. Note that the default QNetworkAccessManager implementation does not support caching. However, this attribute may be used by certain backends to modify their requests (for example, for caching proxies).
`QNetworkRequest::CacheSaveControlAttribute` | `5` | Requests only, type: QMetaType::Bool (default: true) Controls if the data obtained should be saved to cache for future uses. If the value is false, the data obtained will not be automatically cached. If true, data may be cached, provided it is cacheable (what is cacheable depends on the protocol being used).
`QNetworkRequest::SourceIsFromCacheAttribute` | `6` | Replies only, type: QMetaType::Bool (default: false) Indicates whether the data was obtained from cache or not.
`QNetworkRequest::DoNotBufferUploadDataAttribute` | `7` | Requests only, type: QMetaType::Bool (default: false) Indicates whether the QNetworkAccessManager code is allowed to buffer the upload data, e.g. when doing a HTTP POST. When using this flag with sequential upload data, the ContentLengthHeader header must be set.
`QNetworkRequest::HttpPipeliningAllowedAttribute` | `8` | Requests only, type: QMetaType::Bool (default: false) Indicates whether the QNetworkAccessManager code is allowed to use HTTP pipelining with this request.
`QNetworkRequest::HttpPipeliningWasUsedAttribute` | `9` | Replies only, type: QMetaType::Bool Indicates whether the HTTP pipelining was used for receiving this reply.
`QNetworkRequest::CustomVerbAttribute` | `10` | Requests only, type: QMetaType::QByteArray Holds the value for the custom HTTP verb to send (destined for usage of other verbs than GET, POST, PUT and DELETE). This verb is set when calling QNetworkAccessManager::sendCustomRequest().
`QNetworkRequest::CookieLoadControlAttribute` | `11` | Requests only, type: QMetaType::Int (default: QNetworkRequest::Automatic) Indicates whether to send 'Cookie' headers in the request. This attribute is set to false by Qt WebKit when creating a cross-origin XMLHttpRequest where withCredentials has not been set explicitly to true by the Javascript that created the request. See here for more information. (This value was introduced in 4.7.)
`QNetworkRequest::CookieSaveControlAttribute` | `13` | Requests only, type: QMetaType::Int (default: QNetworkRequest::Automatic) Indicates whether to save 'Cookie' headers received from the server in reply to the request. This attribute is set to false by Qt WebKit when creating a cross-origin XMLHttpRequest where withCredentials has not been set explicitly to true by the Javascript that created the request. See here for more information. (This value was introduced in 4.7.)
`QNetworkRequest::AuthenticationReuseAttribute` | `12` | Requests only, type: QMetaType::Int (default: QNetworkRequest::Automatic) Indicates whether to use cached authorization credentials in the request, if available. If this is set to QNetworkRequest::Manual and the authentication mechanism is 'Basic' or 'Digest', Qt will not send an an 'Authorization' HTTP header with any cached credentials it may have for the request's URL. This attribute is set to QNetworkRequest::Manual by Qt WebKit when creating a cross-origin XMLHttpRequest where withCredentials has not been set explicitly to true by the Javascript that created the request. See here for more information. (This value was introduced in 4.7.)
`QNetworkRequest::BackgroundRequestAttribute` | `17` | Type: QMetaType::Bool (default: false) Indicates that this is a background transfer, rather than a user initiated transfer. Depending on the platform, background transfers may be subject to different policies. The QNetworkSession ConnectInBackground property will be set according to this attribute.
`QNetworkRequest::SpdyAllowedAttribute` | `18` | Requests only, type: QMetaType::Bool (default: false) Indicates whether the QNetworkAccessManager code is allowed to use SPDY with this request. This applies only to SSL requests, and depends on the server supporting SPDY.
`QNetworkRequest::SpdyWasUsedAttribute` | `19` | Replies only, type: QMetaType::Bool Indicates whether SPDY was used for receiving this reply.
`QNetworkRequest::EmitAllUploadProgressSignalsAttribute` | `20` | Requests only, type: QMetaType::Bool (default: false) Indicates whether all upload signals should be emitted. By default, the uploadProgress signal is emitted only in 100 millisecond intervals. (This value was introduced in 5.5.)
`QNetworkRequest::FollowRedirectsAttribute` | `21` | Requests only, type: QMetaType::Bool (default: false) Indicates whether the Network Access API should automatically follow a HTTP redirect response or not. Currently redirects that are insecure, that is redirecting from "https" to "http" protocol, are not allowed. (This value was introduced in 5.6.)
`QNetworkRequest::User` | `1000` | Special type. Additional information can be passed in QVariants with types ranging from User to UserMax. The default implementation of Network Access will ignore any request attributes in this range and it will not produce any attributes in this range in replies. The range is reserved for extensions of QNetworkAccessManager.
`QNetworkRequest::UserMax` | `32767` | Special type. See User.

This enum was introduced or modified in Qt 4.7.

### enum QNetworkRequest::CacheLoadControl

Controls the caching mechanism of QNetworkAccessManager.

Constant | Value | Description
--- | --- | ---
`QNetworkRequest::AlwaysNetwork` | `0` | always load from network and do not check if the cache has a valid entry (similar to the "Reload" feature in browsers); in addition, force intermediate caches to re-validate.
`QNetworkRequest::PreferNetwork` | `1` | default value; load from the network if the cached entry is older than the network entry. This will never return stale data from the cache, but revalidate resources that have become stale.
`QNetworkRequest::PreferCache` | `2` | load from cache if available, otherwise load from network. Note that this can return possibly stale (but not expired) items from cache.
`QNetworkRequest::AlwaysCache` | `3` | only load from cache, indicating error if the item was not cached (i.e., off-line mode)

### enum QNetworkRequest::KnownHeaders

List of known header types that QNetworkRequest parses. Each known header is also represented in raw form with its full HTTP name.

Constant | Value | Description
--- | --- | ---
`QNetworkRequest::ContentDispositionHeader` | `6` | Corresponds to the HTTP Content-Disposition header and contains a string containing the disposition type (for instance, attachment) and a parameter (for instance, filename).
`QNetworkRequest::ContentTypeHeader` | `0` | Corresponds to the HTTP Content-Type header and contains a string containing the media (MIME) type and any auxiliary data (for instance, charset).
`QNetworkRequest::ContentLengthHeader` | `1` | Corresponds to the HTTP Content-Length header and contains the length in bytes of the data transmitted.
`QNetworkRequest::LocationHeader` | `2` | Corresponds to the HTTP Location header and contains a URL representing the actual location of the data, including the destination URL in case of redirections.
`QNetworkRequest::LastModifiedHeader` | `3` | Corresponds to the HTTP Last-Modified header and contains a QDateTime representing the last modification date of the contents.
`QNetworkRequest::CookieHeader` | `4` | Corresponds to the HTTP Cookie header and contains a QList<QNetworkCookie> representing the cookies to be sent back to the server.
`QNetworkRequest::SetCookieHeader` | `5` | Corresponds to the HTTP Set-Cookie header and contains a QList<QNetworkCookie> representing the cookies sent by the server to be stored locally.
`QNetworkRequest::UserAgentHeader` | `7` | The User-Agent header sent by HTTP clients.
`QNetworkRequest::ServerHeader` | `8` | The Server header received by HTTP clients.

See also header(), setHeader(), rawHeader(), and setRawHeader().

### enum QNetworkRequest::LoadControl

Indicates if an aspect of the request's loading mechanism has been manually overridden, e.g. by Qt WebKit.

Constant | Value | Description
--- | --- | ---
`QNetworkRequest::Automatic` | `0` | default value: indicates default behaviour.
`QNetworkRequest::Manual` | `1` | indicates behaviour has been manually overridden.

This enum was introduced or modified in Qt 4.7.

### enum QNetworkRequest::Priority

This enum lists the possible network request priorities.

Constant | Value | Description
--- | --- | ---
`QNetworkRequest::HighPriority` | `1` | High priority
`QNetworkRequest::NormalPriority` | `3` | Normal priority
`QNetworkRequest::LowPriority` | `5` | Low priority

This enum was introduced or modified in Qt 4.7.

## Member Function Documentation

### QNetworkRequest::QNetworkRequest(const QUrl &url = QUrl())

Constructs a QNetworkRequest object with url as the URL to be requested.

See also url() and setUrl().

### QNetworkRequest::QNetworkRequest(const QNetworkRequest &other)

Creates a copy of other.

### QNetworkRequest::~QNetworkRequest()

Disposes of the QNetworkRequest object.

### QVariant QNetworkRequest::attribute(Attribute code, const QVariant &defaultValue = QVariant()) const

Returns the attribute associated with the code code. If the attribute has not been set, it returns defaultValue.

Note: This function does not apply the defaults listed in QNetworkRequest::Attribute.

See also setAttribute() and QNetworkRequest::Attribute.

### bool QNetworkRequest::hasRawHeader(const QByteArray &headerName) const

Returns `true` if the raw header headerName is present in this network request.

See also rawHeader() and setRawHeader().

### QVariant QNetworkRequest::header(KnownHeaders header) const

Returns the value of the known network header header if it is present in this request. If it is not present, returns QVariant() (i.e., an invalid variant).

See also KnownHeaders, rawHeader(), and setHeader().

### int QNetworkRequest::maximumRedirectsAllowed() const

Returns the maximum number of redirects allowed to be followed for this request.

This function was introduced in Qt 5.6.

See also setMaximumRedirectsAllowed().

### QObject *QNetworkRequest::originatingObject() const

Returns a reference to the object that initiated this network request; returns 0 if not set or the object has been destroyed.

This function was introduced in Qt 4.6.

See also setOriginatingObject().

### Priority QNetworkRequest::priority() const

Return the priority of this request.

This function was introduced in Qt 4.7.

See also setPriority().

### QByteArray QNetworkRequest::rawHeader(const QByteArray &headerName) const

Returns the raw form of header headerName. If no such header is present, an empty QByteArray is returned, which may be indistinguishable from a header that is present but has no content (use hasRawHeader() to find out if the header exists or not).

Raw headers can be set with setRawHeader() or with setHeader().

See also header() and setRawHeader().

### QList<QByteArray> QNetworkRequest::rawHeaderList() const

Returns a list of all raw headers that are set in this network request. The list is in the order that the headers were set.

See also hasRawHeader() and rawHeader().

### void QNetworkRequest::setAttribute(Attribute code, const QVariant &value)

Sets the attribute associated with code code to be value value. If the attribute is already set, the previous value is discarded. In special, if value is an invalid QVariant, the attribute is unset.

See also attribute() and QNetworkRequest::Attribute.

### void QNetworkRequest::setHeader(KnownHeaders header, const QVariant &value)

Sets the value of the known header header to be value, overriding any previously set headers. This operation also sets the equivalent raw HTTP header.

See also KnownHeaders, setRawHeader(), and header().

### void QNetworkRequest::setMaximumRedirectsAllowed(int maxRedirectsAllowed)

Sets the maximum number of redirects allowed to be followed for this request to maxRedirectsAllowed.

This function was introduced in Qt 5.6.

See also maximumRedirectsAllowed().

### void QNetworkRequest::setOriginatingObject(QObject *object)

Allows setting a reference to the object initiating the request.

For example Qt WebKit sets the originating object to the QWebFrame that initiated the request.

This function was introduced in Qt 4.6.

See also originatingObject().

### void QNetworkRequest::setPriority(Priority priority)

Set the priority of this request to priority.

Note: The priority is only a hint to the network access manager. It can use it or not. Currently it is used for HTTP to decide which request should be sent first to a server.

This function was introduced in Qt 4.7.

See also priority().

### void QNetworkRequest::setRawHeader(const QByteArray &headerName, const QByteArray &headerValue)

Sets the header headerName to be of value headerValue. If headerName corresponds to a known header (see QNetworkRequest::KnownHeaders), the raw format will be parsed and the corresponding "cooked" header will be set as well.

For example:

      request.setRawHeader(QByteArray("Last-Modified"), QByteArray("Sun, 06 Nov 1994 08:49:37 GMT"));

will also set the known header LastModifiedHeader to be the QDateTime object of the parsed date.

Note: Setting the same header twice overrides the previous setting. To accomplish the behaviour of multiple HTTP headers of the same name, you should concatenate the two values, separating them with a comma (",") and set one single raw header.

See also KnownHeaders, setHeader(), hasRawHeader(), and rawHeader().

### void QNetworkRequest::setSslConfiguration(const QSslConfiguration &config)

Sets this network request's SSL configuration to be config. The settings that apply are the private key, the local certificate, the SSL protocol (SSLv2, SSLv3, TLSv1.0 where applicable), the CA certificates and the ciphers that the SSL backend is allowed to use.

By default, no SSL configuration is set, which allows the backends to choose freely what configuration is best for them.

See also sslConfiguration() and QSslConfiguration::defaultConfiguration().

### void QNetworkRequest::setUrl(const QUrl &url)

Sets the URL this network request is referring to be url.

See also url().

### QSslConfiguration QNetworkRequest::sslConfiguration() const

Returns this network request's SSL configuration. By default, no SSL settings are specified.

See also setSslConfiguration().

### void QNetworkRequest::swap(QNetworkRequest &other)

Swaps this network request with other. This function is very fast and never fails.

This function was introduced in Qt 5.0.

### QUrl QNetworkRequest::url() const

Returns the URL this network request is referring to.

See also setUrl().

### bool QNetworkRequest::operator!=(const QNetworkRequest &other) const

Returns `false` if this object is not the same as other.

See also operator==().

### QNetworkRequest &QNetworkRequest::operator=(QNetworkRequest &&other)

Move-assignment operator.

### QNetworkRequest &QNetworkRequest::operator=(const QNetworkRequest &other)

Creates a copy of other

### bool QNetworkRequest::operator==(const QNetworkRequest &other) const

Returns `true` if this object is the same as other (i.e., if they have the same URL, same headers and same meta-data settings).

See also operator!=().