- Qt 5.15
- Qt Network
- C++ Classes
- QHttpMultiPart
- Qt 5.15.19 Reference Documentation

# QHttpMultiPart Class

The QHttpMultiPart class resembles a MIME multipart message to be sent over HTTP. More...

Header: | #include <QHttpMultiPart>
qmake: | QT += network
Since: | Qt 4.8

This class was introduced in Qt 4.8.

- List of all members, including inherited members

## Public Types

enum | ContentType { MixedType, RelatedType, FormDataType, AlternativeType }

## Public Functions

| QHttpMultiPart(ContentType contentType, QObject *parent = nullptr)
| QHttpMultiPart(QObject *parent = nullptr)
virtual | ~QHttpMultiPart()
void | append(const QHttpPart &httpPart)
QByteArray | boundary() const
void | setBoundary(const QByteArray &boundary)
void | setContentType(ContentType contentType)

## Detailed Description

The QHttpMultiPart resembles a MIME multipart message, as described in RFC 2046, which is to be sent over HTTP. A multipart message consists of an arbitrary number of body parts (see QHttpPart), which are separated by a unique boundary. The boundary of the QHttpMultiPart is constructed with the string "boundary_.oOo._" followed by random characters, and provides enough uniqueness to make sure it does not occur inside the parts itself. If desired, the boundary can still be set via setBoundary().

As an example, consider the following code snippet, which constructs a multipart message containing a text part followed by an image part:

     QHttpMultiPart *multiPart = new QHttpMultiPart(QHttpMultiPart::FormDataType);

     QHttpPart textPart;
     textPart.setHeader(QNetworkRequest::ContentDispositionHeader, QVariant("form-data; name=\"text\""));
     textPart.setBody("my text");

     QHttpPart imagePart;
     imagePart.setHeader(QNetworkRequest::ContentTypeHeader, QVariant("image/jpeg"));
     imagePart.setHeader(QNetworkRequest::ContentDispositionHeader, QVariant("form-data; name=\"image\""));
     QFile *file = new QFile("image.jpg");
     file->open(QIODevice::ReadOnly);
     imagePart.setBodyDevice(file);
     file->setParent(multiPart); // we cannot delete the file now, so delete it with the multiPart

     multiPart->append(textPart);
     multiPart->append(imagePart);

     QUrl url("http://my.server.tld");
     QNetworkRequest request(url);

     QNetworkAccessManager manager;
     QNetworkReply *reply = manager.post(request, multiPart);
     multiPart->setParent(reply); // delete the multiPart with the reply
     // here connect signals etc.

See also QHttpPart and QNetworkAccessManager::post().

## Member Type Documentation

### enum QHttpMultiPart::ContentType

List of known content types for a multipart subtype as described in RFC 2046 and others.

Constant | Value | Description
--- | --- | ---
`QHttpMultiPart::MixedType` | `0` | corresponds to the "multipart/mixed" subtype, meaning the body parts are independent of each other, as described in RFC 2046.
`QHttpMultiPart::RelatedType` | `1` | corresponds to the "multipart/related" subtype, meaning the body parts are related to each other, as described in RFC 2387.
`QHttpMultiPart::FormDataType` | `2` | corresponds to the "multipart/form-data" subtype, meaning the body parts contain form elements, as described in RFC 2388.
`QHttpMultiPart::AlternativeType` | `3` | corresponds to the "multipart/alternative" subtype, meaning the body parts are alternative representations of the same information, as described in RFC 2046.

See also setContentType().

## Member Function Documentation

### QHttpMultiPart::QHttpMultiPart(ContentType contentType, QObject *parent = nullptr)

Constructs a QHttpMultiPart with content type contentType and sets parent as the parent object.

See also QHttpMultiPart::ContentType.

### QHttpMultiPart::QHttpMultiPart(QObject *parent = nullptr)

Constructs a QHttpMultiPart with content type MixedType and sets parent as the parent object.

See also QHttpMultiPart::ContentType.

### `[virtual]` QHttpMultiPart::~QHttpMultiPart()

Destroys the multipart.

### void QHttpMultiPart::append(const QHttpPart &httpPart)

Appends httpPart to this multipart.

### QByteArray QHttpMultiPart::boundary() const

returns the boundary.

See also setBoundary().

### void QHttpMultiPart::setBoundary(const QByteArray &boundary)

Sets the boundary to boundary.

Usually, you do not need to generate a boundary yourself; upon construction the boundary is initiated with the string "boundary_.oOo._" followed by random characters, and provides enough uniqueness to make sure it does not occur inside the parts itself.

See also boundary().

### void QHttpMultiPart::setContentType(ContentType contentType)

Sets the content type to contentType. The content type will be used in the HTTP header section when sending the multipart message via QNetworkAccessManager::post(). In case you want to use a multipart subtype not contained in QHttpMultiPart::ContentType, you can add the "Content-Type" header field to the QNetworkRequest by hand, and then use this request together with the multipart message for posting.

See also QHttpMultiPart::ContentType and QNetworkAccessManager::post().