\inmodule QtCore\reentrant More...

#include <qjsondocument.h>

Collaboration diagram for QJsonDocument:

Public Types
enum	JsonFormat { Indented , Compact }

Public Member Functions
	QJsonDocument ()
	Constructs an empty and invalid document.

	QJsonDocument (const QJsonObject &object)
	Creates a QJsonDocument from object.

	QJsonDocument (const QJsonArray &array)
	Constructs a QJsonDocument from array.

	~QJsonDocument ()
	Deletes the document.

	QJsonDocument (const QJsonDocument &other)
	Creates a copy of the other document.

QJsonDocument &	operator= (const QJsonDocument &other)
	Assigns the other document to this QJsonDocument.

	QJsonDocument (QJsonDocument &&other) noexcept

QJsonDocument &	operator= (QJsonDocument &&other) noexcept

void	swap (QJsonDocument &other) noexcept

QVariant	toVariant () const
	Returns a QVariant representing the Json document.

QByteArray	toJson (JsonFormat format=Indented) const

bool	isEmpty () const
	Returns `true` if the document doesn't contain any data.

bool	isArray () const
	Returns `true` if the document contains an array.

bool	isObject () const
	Returns `true` if the document contains an object.

QJsonObject	object () const
	Returns the QJsonObject contained in the document.

QJsonArray	array () const
	Returns the QJsonArray contained in the document.

void	setObject (const QJsonObject &object)
	Sets object as the main object of this document.

void	setArray (const QJsonArray &array)
	Sets array as the main object of this document.

const QJsonValue	operator[] (const QString &key) const
	Returns a QJsonValue representing the value for the key key.

const QJsonValue	operator[] (QStringView key) const
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

const QJsonValue	operator[] (QLatin1StringView key) const
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

const QJsonValue	operator[] (qsizetype i) const
	Returns a QJsonValue representing the value for index i.

bool	isNull () const
	returns `true` if this document is null.

Static Public Member Functions
static QJsonDocument	fromVariant (const QVariant &variant)
	Creates a QJsonDocument from the QVariant variant.

static QJsonDocument	fromJson (const QByteArray &json, QJsonParseError *error=nullptr)
	Parses json as a UTF-8 encoded JSON document, and creates a QJsonDocument from it.

Static Public Attributes
static const uint	BinaryFormatTag = ('q' << 24) \| ('b' << 16) \| ('j' << 8) \| ('s')

Friends
class	QJsonValue

class	QJsonPrivate::Parser

Q_CORE_EXPORT QDebug	operator<< (QDebug dbg, const QJsonDocument &o)

Q_CORE_EXPORT bool	comparesEqual (const QJsonDocument &lhs, const QJsonDocument &rhs)

Detailed Description

\inmodule QtCore

\reentrant

Since: 5.0

The QJsonDocument class provides a way to read and write JSON documents.

\compares equality

QJsonDocument is a class that wraps a complete JSON document and can read this document from, and write it to, a UTF-8 encoded text-based representation.

A JSON document can be converted from its text-based representation to a QJsonDocument using QJsonDocument::fromJson(). toJson() converts it back to text. The parser is very fast and efficient and converts the JSON to the binary representation used by Qt.

Validity of the parsed document can be queried with !isNull()

A document can be queried as to whether it contains an array or an object using isArray() and isObject(). The array or object contained in the document can be retrieved using array() or object() and then read or manipulated.

See also: {JSON Support in Qt}, {Saving and Loading a Game}

Definition at line 47 of file qjsondocument.h.

Member Enumeration Documentation

◆ JsonFormat

enum QJsonDocument::JsonFormat

Since: 5.1

This value defines the format of the JSON byte array produced when converting to a QJsonDocument using toJson().

\value Indented Defines human readable output as follows:

    {
        "Array": [
            true,
            999,
            "string"
        ],
        "Key": "Value",
        "null": null
    }

\value Compact Defines a compact output as follows:

{"Array":[true,999,"string"],"Key":"Value","null":null}

Enumerator
Indented
Compact

Definition at line 77 of file qjsondocument.h.

Constructor & Destructor Documentation

◆ QJsonDocument() [1/5]

QJsonDocument::QJsonDocument ( )

Constructs an empty and invalid document.

Definition at line 66 of file qjsondocument.cpp.

◆ QJsonDocument() [2/5]

QJsonDocument::QJsonDocument ( const QJsonObject & object )

explicit

Creates a QJsonDocument from object.

Definition at line 74 of file qjsondocument.cpp.

◆ QJsonDocument() [3/5]

QJsonDocument::QJsonDocument ( const QJsonArray & array )

explicit

Constructs a QJsonDocument from array.

Definition at line 83 of file qjsondocument.cpp.

◆ ~QJsonDocument()

QJsonDocument::~QJsonDocument ( )

default

Deletes the document.

Binary data set with fromRawData is not freed.

◆ QJsonDocument() [4/5]

QJsonDocument::QJsonDocument ( const QJsonDocument & other )

Creates a copy of the other document.

Definition at line 108 of file qjsondocument.cpp.

◆ QJsonDocument() [5/5]

QJsonDocument::QJsonDocument ( QJsonDocument && other )

noexcept

Since: 5.10

Move-constructs a QJsonDocument from other.

Definition at line 119 of file qjsondocument.cpp.

Member Function Documentation

◆ array()

QJsonArray QJsonDocument::array ( ) const

Returns the QJsonArray contained in the document.

Returns an empty array if the document contains an object.

See also: isArray(), object(), setArray()

Definition at line 341 of file qjsondocument.cpp.

◆ fromJson()

QJsonDocument QJsonDocument::fromJson	(	const QByteArray &	json,
		QJsonParseError *	error = nullptr )

static

Parses json as a UTF-8 encoded JSON document, and creates a QJsonDocument from it.

Returns a valid (non-null) QJsonDocument if the parsing succeeds. If it fails, the returned document will be null, and the optional error variable will contain further details about the error.

See also: toJson(), QJsonParseError, isNull()

Definition at line 267 of file qjsondocument.cpp.

◆ fromVariant()

QJsonDocument QJsonDocument::fromVariant ( const QVariant & variant )

static

Creates a QJsonDocument from the QVariant variant.

If the variant contains any other type than a QVariantMap, QVariantHash, QVariantList or QStringList, the returned document is invalid.

See also: toVariant()

Definition at line 176 of file qjsondocument.cpp.

◆ isArray()

bool QJsonDocument::isArray ( ) const

Returns true if the document contains an array.

See also: array(), isObject()

Definition at line 295 of file qjsondocument.cpp.

◆ isEmpty()

bool QJsonDocument::isEmpty ( ) const

Returns true if the document doesn't contain any data.

Definition at line 282 of file qjsondocument.cpp.

◆ isNull()

bool QJsonDocument::isNull ( ) const

returns true if this document is null.

Null documents are documents created through the default constructor.

Documents created from UTF-8 encoded text or the binary format are validated during parsing. If validation fails, the returned document will also be null.

Definition at line 464 of file qjsondocument.cpp.

◆ isObject()

bool QJsonDocument::isObject ( ) const

Returns true if the document contains an object.

See also: object(), isArray()

Definition at line 308 of file qjsondocument.cpp.

◆ object()

QJsonObject QJsonDocument::object ( ) const

Returns the QJsonObject contained in the document.

Returns an empty object if the document contains an array.

See also: isObject(), array(), setObject()

Definition at line 324 of file qjsondocument.cpp.

◆ operator=() [1/2]

QJsonDocument & QJsonDocument::operator= ( const QJsonDocument & other )

Assigns the other document to this QJsonDocument.

Returns a reference to this object.

Definition at line 133 of file qjsondocument.cpp.

◆ operator=() [2/2]

QJsonDocument & QJsonDocument::operator= ( QJsonDocument && other )

inlinenoexcept

Since: 5.10

Move-assigns other to this document.

Definition at line 66 of file qjsondocument.h.

◆ operator[]() [1/4]

const QJsonValue QJsonDocument::operator[] ( const QString & key ) const

Returns a QJsonValue representing the value for the key key.

Equivalent to calling object().value(key).

The returned QJsonValue is QJsonValue::Undefined if the key does not exist, or if isObject() is false.

Since: 5.10

See also: QJsonValue, QJsonValue::isUndefined(), QJsonObject

Definition at line 388 of file qjsondocument.cpp.

◆ operator[]() [2/4]

const QJsonValue QJsonDocument::operator[] ( QLatin1StringView key ) const

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Since: 5.10

Definition at line 409 of file qjsondocument.cpp.

◆ operator[]() [3/4]

const QJsonValue QJsonDocument::operator[] ( qsizetype i ) const

Returns a QJsonValue representing the value for index i.

Equivalent to calling array().at(i).

The returned QJsonValue is QJsonValue::Undefined, if i is out of bounds, or if isArray() is false.

Since: 5.10

See also: QJsonValue, QJsonValue::isUndefined(), QJsonArray

Definition at line 429 of file qjsondocument.cpp.

◆ operator[]() [4/4]

const QJsonValue QJsonDocument::operator[] ( QStringView key ) const

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Since: 5.14

Definition at line 397 of file qjsondocument.cpp.

◆ setArray()

void QJsonDocument::setArray ( const QJsonArray & array )

Sets array as the main object of this document.

See also: setObject(), array()

Definition at line 368 of file qjsondocument.cpp.

◆ setObject()

void QJsonDocument::setObject ( const QJsonObject & object )

Sets object as the main object of this document.

See also: setArray(), object()

Definition at line 355 of file qjsondocument.cpp.

◆ swap()

void QJsonDocument::swap ( QJsonDocument & other )

noexcept

Since: 5.10 \memberswap{document}

Definition at line 124 of file qjsondocument.cpp.

◆ toJson()

QByteArray QJsonDocument::toJson ( JsonFormat format = Indented ) const

Since: 5.1 Converts the QJsonDocument to a UTF-8 encoded JSON document in the provided format.

See also: fromJson(), JsonFormat

Definition at line 241 of file qjsondocument.cpp.

◆ toVariant()

QVariant QJsonDocument::toVariant ( ) const

Returns a QVariant representing the Json document.

The returned variant will be a QVariantList if the document is a QJsonArray and a QVariantMap if the document is a QJsonObject.

See also: fromVariant(), QJsonValue::toVariant()

Definition at line 208 of file qjsondocument.cpp.

Friends And Related Symbol Documentation

◆ comparesEqual

Q_CORE_EXPORT bool comparesEqual	(	const QJsonDocument &	lhs,
		const QJsonDocument &	rhs )

friend

Definition at line 442 of file qjsondocument.cpp.

◆ operator<<

Q_CORE_EXPORT QDebug operator<<	(	QDebug	dbg,
		const QJsonDocument &	o )

friend

Definition at line 470 of file qjsondocument.cpp.

◆ QJsonPrivate::Parser

friend class QJsonPrivate::Parser

friend

Definition at line 110 of file qjsondocument.h.

◆ QJsonValue

friend class QJsonValue

friend

Definition at line 109 of file qjsondocument.h.

Member Data Documentation

◆ BinaryFormatTag

const uint QJsonDocument::BinaryFormatTag = ('q' << 24) | ('b' << 16) | ('j' << 8) | ('s')

static

Definition at line 53 of file qjsondocument.h.

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

qtbase/src/corelib/serialization/qjsondocument.h (e2bd247081e632236ee7d32bac90cd2018691dbb)
qtbase/src/corelib/serialization/qjsondocument.cpp (82058367923ce164024885854c139ee5e0d89949)

Public Types

Public Member Functions

Static Public Member Functions

Static Public Attributes

Friends

Detailed Description

Member Enumeration Documentation

◆ JsonFormat

Constructor & Destructor Documentation

◆ QJsonDocument() [1/5]

◆ QJsonDocument() [2/5]

◆ QJsonDocument() [3/5]

◆ ~QJsonDocument()

◆ QJsonDocument() [4/5]

◆ QJsonDocument() [5/5]

Member Function Documentation

◆ array()

◆ fromJson()

◆ fromVariant()

◆ isArray()

◆ isEmpty()

◆ isNull()

◆ isObject()

◆ object()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ operator[]() [1/4]

◆ operator[]() [2/4]

◆ operator[]() [3/4]

◆ operator[]() [4/4]

◆ setArray()

◆ setObject()

◆ swap()

◆ toJson()

◆ toVariant()

Friends And Related Symbol Documentation

◆ comparesEqual

◆ operator<<

◆ QJsonPrivate::Parser

◆ QJsonValue

Member Data Documentation

◆ BinaryFormatTag