Class DeltaFileWrapper

ClassList > DeltaFileWrapper

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• #include <deltafilewrapper.h>

Inherits the following classes: QObject

Public Types

Type	Name
enum	ErrorType

Public Properties

Type	Name
property int	count
property QString	errorString
property ErrorType	errorType
property bool	hasError
property bool	isPushing

Public Signals

Type	Name
signal void	countChanged
signal void	errorChanged
signal void	isPushingChanged
signal void	savedToFile

Public Functions

Type	Name
	DeltaFileWrapper (const QString & projectId, const QString & fileName)
void	addCreate (const QgsProject * project, const QString & localLayerId, const QString & sourceLayerId, const QString & localPkAttrName, const QString & sourcePkAttrName, const QgsFeature & newFeature)
void	addDelete (const QgsProject * project, const QString & localLayerId, const QString & sourceLayerId, const QString & localPkAttrName, const QString & sourcePkAttrName, const QgsFeature & oldFeature)
void	addPatch (const QgsProject * project, const QString & localLayerId, const QString & sourceLayerId, const QString & localPkAttrName, const QString & sourcePkAttrName, const QgsFeature & oldFeature, const QgsFeature & newFeature, bool storeSnapshot=true)
bool	append (const DeltaFileWrapper * deltaFileWrapper)
Q_INVOKABLE bool	apply (const QgsProject * project)
Q_INVOKABLE bool	applyReversed (const QgsProject * project)
QMap< QString, QString >	attachmentFileNames () const
Q_INVOKABLE int	count () const
QStringList	deltaLayerIds () const
QJsonArray	deltas () const
QString	errorString () const
ErrorType	errorType () const
QString	fileName () const
int	getDeltaIndexByUuid (const QString & uuid) const
bool	hasError () const
QString	id () const
Q_INVOKABLE bool	isCreatedFeature (QgsVectorLayer * vl, QgsFeature feature)
bool	isDeltaBeingApplied () const
bool	isDirty () const
bool	isPushing () const
QString	projectId () const
Q_INVOKABLE void	reset ()
Q_INVOKABLE void	resetId ()
void	setIsPushing (bool isPushing)
Q_INVOKABLE bool	toFile ()
Q_INVOKABLE QString	toFileForPush (const QString & outFileName=QString()) const
QByteArray	toJson (QJsonDocument::JsonFormat jsonFormat=QJsonDocument::Indented) const
QString	toString () const
	~DeltaFileWrapper ()

Public Static Functions

Type	Name
QStringList	attachmentFieldNames (const QgsProject * project, const QString & layerId)
QString	crsByLayerId (const QgsProject * project, const QString & layerId)
QPair< int, QString >	getLocalPkAttribute (const QgsVectorLayer * vl) Get a pair of the index and the name of the primary key column of given vl layer. We assume there is no multi-column primary key.
QString	getSourceLayerId (const QgsVectorLayer * vl)
QPair< int, QString >	getSourcePkAttribute (const QgsVectorLayer * vl) Get a pair of the index and the name of the primary key column of given vl layer, as they are in the original source.
QString	nameByLayerId (const QgsProject * project, const QString & layerId)

Detailed Description

A class that wraps the operations with a delta file. All read and write operations to a delta file should go through this class.

Public Types Documentation

enum ErrorType

enum DeltaFileWrapper::ErrorType {
    NoError,
    LockError,
    NotCloudProjectError,
    IOError,
    JsonParseError,
    JsonFormatIdError,
    JsonFormatProjectIdError,
    JsonFormatVersionError,
    JsonFormatDeltasError,
    JsonFormatDeltaItemError,
    JsonIncompatibleVersionError
};

Error types

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Public Properties Documentation

property count [1/2]

int DeltaFileWrapper::count;

---

property errorString [1/2]

QString DeltaFileWrapper::errorString;

---

property errorType [1/2]

ErrorType DeltaFileWrapper::errorType;

---

property hasError [1/2]

bool DeltaFileWrapper::hasError;

---

property isPushing [1/2]

bool DeltaFileWrapper::isPushing;

---

Public Signals Documentation

signal countChanged

void DeltaFileWrapper::countChanged;

Emitted when the deltas list has changed.

---

signal errorChanged

void DeltaFileWrapper::errorChanged;

Emmitted when the latest error has changed

---

signal isPushingChanged

void DeltaFileWrapper::isPushingChanged;

Emmitted when the pushing state has changed.

---

signal savedToFile

void DeltaFileWrapper::savedToFile;

Emmitted when the deltas have been written to a file

---

Public Functions Documentation

function DeltaFileWrapper

DeltaFileWrapper::DeltaFileWrapper (
    const QString & projectId,
    const QString & fileName
) 

Construct a new Feature Deltas object.

Parameters:

• project the current project
• fileName complete file name with path where the object should be stored

---

function addCreate

void DeltaFileWrapper::addCreate (
    const QgsProject * project,
    const QString & localLayerId,
    const QString & sourceLayerId,
    const QString & localPkAttrName,
    const QString & sourcePkAttrName,
    const QgsFeature & newFeature
) 

Adds create delta.

Parameters:

• localLayerId layer ID where the old feature belongs to
• sourceLayerId layer ID where the old feature belongs to
• localPkAttrName attribute name of the primary key
• sourcePkAttrName attribute name of the primary key
• newFeature the feature that has been created

---

function addDelete

void DeltaFileWrapper::addDelete (
    const QgsProject * project,
    const QString & localLayerId,
    const QString & sourceLayerId,
    const QString & localPkAttrName,
    const QString & sourcePkAttrName,
    const QgsFeature & oldFeature
) 

Adds delete delta.

Parameters:

• localLayerId layer ID where the old feature belongs to
• sourceLayerId layer ID where the old feature belongs to
• localPkAttrName attribute name of the primary key
• sourcePkAttrName attribute name of the primary key
• oldFeature the feature that has been deleted

---

function addPatch

void DeltaFileWrapper::addPatch (
    const QgsProject * project,
    const QString & localLayerId,
    const QString & sourceLayerId,
    const QString & localPkAttrName,
    const QString & sourcePkAttrName,
    const QgsFeature & oldFeature,
    const QgsFeature & newFeature,
    bool storeSnapshot=true
) 

Adds patch delta.

Parameters:

• localLayerId layer ID where the old feature belongs to
• sourceLayerId layer ID where the old feature belongs to
• localPkAttrName attribute name of the primary key
• sourcePkAttrName attribute name of the primary key
• oldFeature the old version of the feature that has been modified
• newFeature the new version of the feature that has been modified
• storeSnapshot store a complete snapshot of the feature

---

function append

bool DeltaFileWrapper::append (
    const DeltaFileWrapper * deltaFileWrapper
) 

Appends the provided deltas JSON array at the end of the current file.

---

function apply

Q_INVOKABLE bool DeltaFileWrapper::apply (
    const QgsProject * project
) 

Attempts to apply a delta file. The list of deltas is not being reset after successfull application and should be handled by the caller.

Note:

it is not guaranteed that the project layers have not changed in case of failure

Returns:

whether the attempt was successful

Todo

TEST

---

function applyReversed

Q_INVOKABLE bool DeltaFileWrapper::applyReversed (
    const QgsProject * project
) 

Attempts to apply a delta file in reverse order (resulting in local changes being discarded). The list of deltas is not being reset after successfull application and should be handled by the caller.

Note:

it is not guaranteed that the project layers have not changed in case of failure

Returns:

whether the attempt was successful.

Todo

TEST

---

function attachmentFileNames

QMap< QString, QString > DeltaFileWrapper::attachmentFileNames () const

Returns a set of file names to be uploaded

Returns:

QMap<QString, QString> unique file names

---

function count [2/2]

Q_INVOKABLE int DeltaFileWrapper::count () const

Returns the number of delta elements

Returns:

int number of delta elements

---

function deltaLayerIds

QStringList DeltaFileWrapper::deltaLayerIds () const

Returns the list of layers that have applied deltas on them.

Returns:

list of layers ids

Todo

TEST

---

function deltas

QJsonArray DeltaFileWrapper::deltas () const

Returns the deltas as a JSON array of delta elements

Returns:

QJsonArray deltas JSON array

---

function errorString [2/2]

QString DeltaFileWrapper::errorString () const

Human readable error description why the class has an error.

Returns:

QString human readable error reason

---

function errorType [2/2]

ErrorType DeltaFileWrapper::errorType () const

Error type why the class has an error.

Returns:

ErrorType error type

---

function fileName

QString DeltaFileWrapper::fileName () const

Returns deltas file name.

Returns:

QString file name

---

function getDeltaIndexByUuid

int DeltaFileWrapper::getDeltaIndexByUuid (
    const QString & uuid
) const

Retuns the index position of a delta with given uuid in the deltas list or -1 if missing.

Parameters:

• uuid the uuid we are looking for

---

function hasError [2/2]

bool DeltaFileWrapper::hasError () const

Returns whether the class has encountered I/O error regarding the delta file. If true is returned, the behaviour of the class instance is no more defined.

Returns:

bool whether an error has been encountered

---

function id

QString DeltaFileWrapper::id () const

Returns deltas file id.

Returns:

QString id

---

function isCreatedFeature

Q_INVOKABLE bool DeltaFileWrapper::isCreatedFeature (
    QgsVectorLayer * vl,
    QgsFeature feature
) 

Returns TRUE if a feature from a given vector layer is recorded as being created in the deltas file.

Parameters:

• vl the vector layer
• feature the feature

---

function isDeltaBeingApplied

bool DeltaFileWrapper::isDeltaBeingApplied () const

Whether or not the current delta file is being applied.

Todo

TEST

---

function isDirty

bool DeltaFileWrapper::isDirty () const

Returns whether the instance contents differs from the data saved on the disk.

Returns:

bool whether there is a difference with the data saved on the disk

---

function isPushing [2/2]

inline bool DeltaFileWrapper::isPushing () const

Returns TRUE if the pushing state is active.

---

function projectId

QString DeltaFileWrapper::projectId () const

Returns deltas file project id.

Returns:

QString project id

---

function reset

Q_INVOKABLE void DeltaFileWrapper::reset () 

Clears the deltas from memory as there are no deltas at all. Does not affect the permanent storage until toFile() is called.

---

function resetId

Q_INVOKABLE void DeltaFileWrapper::resetId () 

Assigns a new unique delta file id.

---

function setIsPushing

void DeltaFileWrapper::setIsPushing (
    bool isPushing
) 

Sets the pushing state.

Parameters:

• isPushing set to TRUE to reflect an ongoing pushing state.

---

function toFile

Q_INVOKABLE bool DeltaFileWrapper::toFile () 

Writes deltas file to the permanent storage.

Returns:

bool whether write has been successful

---

function toFileForPush

Q_INVOKABLE QString DeltaFileWrapper::toFileForPush (
    const QString & outFileName=QString()
) const

Writes deltas file to the permanent storage with replaced layerIds, ready for upload.

Returns:

QString an empty string

---

function toJson

QByteArray DeltaFileWrapper::toJson (
    QJsonDocument::JsonFormat jsonFormat=QJsonDocument::Indented
) const

Returns deltas as JSON QByteArray, ready for I/O operations.

Parameters:

• jsonFormat formatting of the output JSON. Default: QJsonDocument::Indented

Returns:

QByteArray JSON representation

---

function toString

QString DeltaFileWrapper::toString () const

Returns deltas as JSON string.

Returns:

QString JSON representation

---

function ~DeltaFileWrapper

DeltaFileWrapper::~DeltaFileWrapper () 

Destroy the Delta File Wrapper object

---

Public Static Functions Documentation

function attachmentFieldNames

static QStringList DeltaFileWrapper::attachmentFieldNames (
    const QgsProject * project,
    const QString & layerId
) 

Returns a list of field names that have edit form as attachments

Parameters:

• project current project instance
• layerId layer ID

Returns:

QStringList list of field names

---

function crsByLayerId

static QString DeltaFileWrapper::crsByLayerId (
    const QgsProject * project,
    const QString & layerId
) 

Returns the CRS as WKT for given layerId in the project

---

function getLocalPkAttribute

Get a pair of the index and the name of the primary key column of given vl layer. We assume there is no multi-column primary key.

static QPair< int, QString > DeltaFileWrapper::getLocalPkAttribute (
    const QgsVectorLayer * vl
) 

---

function getSourceLayerId

static QString DeltaFileWrapper::getSourceLayerId (
    const QgsVectorLayer * vl
) 

Get the layer id as it is in the original source.

---

function getSourcePkAttribute

Get a pair of the index and the name of the primary key column of given vl layer, as they are in the original source.

static QPair< int, QString > DeltaFileWrapper::getSourcePkAttribute (
    const QgsVectorLayer * vl
) 

---

function nameByLayerId

static QString DeltaFileWrapper::nameByLayerId (
    const QgsProject * project,
    const QString & layerId
) 

Returns the name for given layerId in the project

---

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The documentation for this class was generated from the following file src/core/qfieldcloud/deltafilewrapper.h