Value class that contains a error. More...

#include <Error.h>

Public Types

Public Member Functions
	Error ()
	Construct a null error.

template<typename T >
	Error (const T &error, const QString &text, Level level, const QString &fileName, int fileLine, const QString &className, const QString &functionName)
	Construct a error with error and source set. More...

template<typename T >
	Error (const T &error, const QString &text, Level level, const QString &fileName, int fileLine, const QObject *const obj, const QString &functionName)
	Construct a error with error and source set. More...

	Error (const Error &)=default
	Construct a copy of other error.

bool	isNull () const
	Check if error is null. More...

void	clear ()
	Clear error. More...

void	setError (const QString &text, Level level)
	Set error.

template<typename T >
void	setError (const T &error, const QString &text, Level level)
	Set user defined error. More...

template<typename T >
T	error () const
	Get user defined error. More...

void	updateText (const QString &text)
	Update error text. More...

void	setInformativeText (const QString &text)
	Set informative text. More...

QString	informativeText () const
	Get informative text. More...

Level	level () const
	Get error level. More...

QString	text () const
	Get error text. More...

void	stackError (const Error &error)
	Stack given error. More...

std::vector< Error >	getErrorStack () const
	Get error stack. More...

void	setSource (const QString &fileName, int fileLine, const QString &className, const QString &functionName)
	Add the source of error. More...

void	setSource (const QString &fileName, int fileLine, const QObject *const obj, const QString &functionName)
	Add the source of error. More...

void	commit ()
	Commit error. More...

QString	functionName () const
	Ger error source function. More...

QString	fileName () const
	Get error source file (name only) More...

int	fileLine () const
	Get error source line.

Static Public Member Functions
static Error	fromQFileDevice (const QFileDevice &fileDevice, const QString &sourceCodeFile, int line, const QString &className, const QString &functionName)
	Get a Mdt::Error from last error in fileDevice. More...

static Error	fromQFileDevice (const QFileDevice &fileDevice, const QString &sourceCodeFile, int line, const QObject *const obj, const QString &functionName)
	Get a Mdt::Error from last error in fileDevice. More...

Detailed Description

Value class that contains a error.

Error contains only a pointer to (implicitly) shared data (also known as copy-on-write). As long as no error was set, no more memory is allocated. This allows to store a Error object with a few overhead.

Concept of error stack

Imagine a case of a application that provides document editing functionnality, and the user wants to save a document. The application will probably call a helper function from its own library, which also calls a other system function from a onther part of the library, which finally calls a (maybe system dependant) low level function. The low level function fails (for some reason). How could the application provide the most usefull error message to the user ? Lets illustrate a possible call stack:

Function	Error	Error message
write()	EDQUOT (int)	Disk quota exhausted
writeToFile()	DiskQuotaExhausted (enum)	Could not write to file 'document.txt' because disk quota exhausted
saveDocument()		Could not save your work to 'document.txt'. This is because you reached the disk quota. Please try to save the document to a other place and contact your administrator to solve the problem.

In above scenario, the application can build appropriate message because it knows what DiskQuotaExhausted means. For some other errors (that the application currently not handles), it could also simply display the error returned from saveDocument(). To implement such error stack, simply, at each level, stack a error that a function returns to current error. For example, in writeToFile(), if write() fails, we create a new Error, and return it. Then, saveDocument() will fail, create its own Error object, and stack the one returned by writeToFile(). To stack a error, use stackError() , and use getErrorStack() to get stacked errors back.

If you need to send Error object across threads with Qt signal/slot (queued), Error must be registered with qRegisterMetaType(). This is allready done in Mdt::Application::init(). If you don't use Mdt::Application, don't forget to call qRegisterMetaType<Mdt::Error>() in, f.ex., your main() function.

Definition at line 260 of file Error.h.

Member Enumeration Documentation

enum Mdt::Error::Level : short

Error level.

Enumerator
NoError	No error .
Info	Just a information, application continues to work in normal way .
Warning	Error that could be handled
Critical	Error that was not handled

Definition at line 266 of file Error.h.

Constructor & Destructor Documentation

template<typename T >

Mdt::Error::Error	(	const T &	error,
		const QString &	text,
		Level	level,
		const QString &	fileName,
		int	fileLine,
		const QString &	className,
		const QString &	functionName
	)

inlineexplicit

Construct a error with error and source set.

Calling this constructor directly is a bit long. Consider using mdtErrorNew() or mdtErrorNewT() macro.

Definition at line 284 of file Error.h.

template<typename T >

Mdt::Error::Error	(	const T &	error,
		const QString &	text,
		Level	level,
		const QString &	fileName,
		int	fileLine,
		const QObject *const	obj,
		const QString &	functionName
	)

inlineexplicit

Construct a error with error and source set.

Calling this constructor directly is a bit long. Consider using mdtErrorNewQ() or mdtErrorNewTQ() macro.

Definition at line 300 of file Error.h.

Member Function Documentation

void Mdt::Error::clear ( )

Clear error.

Will also free internal resources. After clear, the error is null.

Definition at line 40 of file Error.cpp.

void Mdt::Error::commit ( )

Commit error.

Will use mdt::error::Logger to output the error.

Definition at line 142 of file Error.cpp.

template<typename T >

T Mdt::Error::error ( ) const

inline

Get user defined error.

If no error was set, a default constructed error of type T is returned.

Precondition: Requested type T must match the one that was stored with setError()

Definition at line 370 of file Error.h.

QString Mdt::Error::fileName ( ) const

Get error source file (name only)

If no error was set, a empty string is returned.

See also: isNull()

Definition at line 148 of file Error.cpp.

Error Mdt::Error::fromQFileDevice	(	const QFileDevice &	fileDevice,
		const QString &	sourceCodeFile,
		int	line,
		const QString &	className,
		const QString &	functionName
	)

static

Get a Mdt::Error from last error in fileDevice.

See also: mdtErrorFromQFileDevice()

Definition at line 196 of file Error.cpp.

Error Mdt::Error::fromQFileDevice	(	const QFileDevice &	fileDevice,
		const QString &	sourceCodeFile,
		int	line,
		const QObject *const	obj,
		const QString &	functionName
	)

static

Get a Mdt::Error from last error in fileDevice.

See also: mdtErrorFromQFileDeviceQ()

Definition at line 208 of file Error.cpp.

QString Mdt::Error::functionName ( ) const

Ger error source function.

If no error was set, a empty string is returned.

See also: isNull()

Definition at line 164 of file Error.cpp.

std::vector< Error > Mdt::Error::getErrorStack ( ) const

Get error stack.

If no error was set, a empty stack is returned.

Note: The returned stack is rebuilt at each call.

See also: stackError(); isNull()

Definition at line 103 of file Error.cpp.

QString Mdt::Error::informativeText ( ) const

Get informative text.

See also: setInformativeText()

Definition at line 61 of file Error.cpp.

bool Mdt::Error::isNull ( ) const

inline

Check if error is null.

Returns true as long as no error was set, or after clear was called.

Definition at line 321 of file Error.h.

Error::Level Mdt::Error::level ( ) const

Get error level.

If no error was set, NoError is returned.

See also: isNull()

Definition at line 69 of file Error.cpp.

template<typename T >

void Mdt::Error::setError	(	const T &	error,
		const QString &	text,
		Level	level
	)

inline

Set user defined error.

Setting error will clear it first.

Template Parameters

T	Type of user defined error.

Parameters

error Error of type T that will be stored.

Precondition: error type T must be default and copy constructible.

Definition at line 352 of file Error.h.

void Mdt::Error::setInformativeText ( const QString & text )

Set informative text.

Can be set to give the user a fuller description of the error. This is the same meaning than QMessageBox, and is used the same way in mdtErrorDialog.

Precondition: this error must not be null when calling this function

See also: informativeText()

Definition at line 53 of file Error.cpp.

void Mdt::Error::setSource	(	const QString &	fileName,
		int	fileLine,
		const QString &	className,
		const QString &	functionName
	)

Add the source of error.

It's possible to use the helper macro MDT_ERROR_SET_SRC()

Precondition: this error must not be null when calling this function

Definition at line 120 of file Error.cpp.

void Mdt::Error::setSource	(	const QString &	fileName,
		int	fileLine,
		const QObject *const	obj,
		const QString &	functionName
	)

Add the source of error.

Avoids typing className by hand. Note that this only works on functions that are QObject (subclasses).

It's possible to use the helper macro MDT_ERROR_SET_SRC_Q()

Precondition: this error must not be null when calling this function

Definition at line 134 of file Error.cpp.

void Mdt::Error::stackError ( const Error & error )

Stack given error.

Precondition: this error and given error must not be null

See also: getErrorStack()

Definition at line 85 of file Error.cpp.

QString Mdt::Error::text ( ) const

Get error text.

If no error was set, a empty string is returned.

See also: isNull()

Definition at line 77 of file Error.cpp.

void Mdt::Error::updateText ( const QString & text )

Update error text.

See also: stackError()

Definition at line 45 of file Error.cpp.

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

libs/Error_Core/src/Mdt/Error.h
libs/Error_Core/src/Mdt/Error.cpp

Public Types

Public Member Functions

Static Public Member Functions

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation