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	1	% automatically generated by HelpGen from tempfile.tex at 10/Jan/99 19:24:44
	2	\section{\class{wxTempFile}}\label{wxtempfile}
	3
	4	wxTempFile provides a relatively safe way to replace the contents of the
	5	existing file. The name is explained by the fact that it may be also used as
	6	just a temporary file if you don't replace the old file contents.
	7
	8	Usually, when a program replaces the contents of some file it first opens it for
	9	writing, thus losing all of the old data and then starts recreating it. This
	10	approach is not very safe because during the regeneration of the file bad things
	11	may happen: the program may find that there is an internal error preventing it
	12	from completing file generation, the user may interrupt it (especially if file
	13	generation takes long time) and, finally, any other external interrupts (power
	14	supply failure or a disk error) will leave you without either the original file
	15	or the new one.
	16
	17	wxTempFile addresses this problem by creating a temporary file which is meant to
	18	replace the original file - but only after it is fully written. So, if the user
	19	interrupts the program during the file generation, the old file won't be lost.
	20	Also, if the program discovers itself that it doesn't want to replace the old
	21	file there is no problem - in fact, wxTempFile will {\bf not} replace the old
	22	file by default, you should explicitly call \helpref{Commit}{wxtempfilecommit}
	23	to do it. Calling \helpref{Discard}{wxtempfilediscard} explicitly discards any
	24	modifications: it closes and deletes the temporary file and leaves the original
	25	file unchanged. If you don't call neither of Commit() and Discard(), the
	26	destructor will call Discard() automatically.
	27
	28	To summarize: if you want to replace another file, create an instance of
	29	wxTempFile passing the name of the file to be replaced to the constructor (you
	30	may also use default constructor and pass the file name to
	31	\helpref{Open}{wxtempfileopen}). Then you can \helpref{write}{wxtempfilewrite}
	32	to wxTempFile using \helpref{wxFile}{wxfile}-like functions and later call
	33	Commit() to replace the old file (and close this one) or call Discard() to cancel
	34	the modifications.
	35
	36	\wxheading{Derived from}
	37
	38	No base class
	39
	40	\wxheading{Include files}
	41
	42	<wx/file.h>
	43
	44	\wxheading{See also:}
	45
	46	\helpref{wxFile}{wxfile}\\
	47	\helpref{wxTempFileOutputStream}{wxtempfileoutputstream}
	48
	49	\latexignore{\rtfignore{\wxheading{Members}}}
	50
	51	\membersection{wxTempFile::wxTempFile}\label{wxtempfilewxtempfilector}
	52
	53	\func{}{wxTempFile}{\void}
	54
	55	Default constructor - \helpref{Open}{wxtempfileopen} must be used to open the
	56	file.
	57
	58	\membersection{wxTempFile::wxTempFile}\label{wxtempfilewxtempfile}
	59
	60	\func{}{wxTempFile}{\param{const wxString\& }{strName}}
	61
	62	Associates wxTempFile with the file to be replaced and opens it. You should use
	63	\helpref{IsOpened}{wxtempfileisopened} to verify if the constructor succeeded.
	64
	65	\membersection{wxTempFile::Open}\label{wxtempfileopen}
	66
	67	\func{bool}{Open}{\param{const wxString\& }{strName}}
	68
	69	Open the temporary file, returns {\tt true} on success, {\tt false} if an error
	70	occurred.
	71
	72	{\it strName} is the name of file to be replaced. The temporary file is always
	73	created in the directory where {\it strName} is. In particular, if
	74	{\it strName} doesn't include the path, it is created in the current directory
	75	and the program should have write access to it for the function to succeed.
	76
	77	\membersection{wxTempFile::IsOpened}\label{wxtempfileisopened}
	78
	79	\constfunc{bool}{IsOpened}{\void}
	80
	81	Returns {\tt true} if the file was successfully opened.
	82
	83	\membersection{wxTempFile::Length}\label{wxtempfilelength}
	84
	85	\constfunc{wxFileOffset}{Length}{\void}
	86
	87	Returns the length of the file.
	88
	89	\membersection{wxTempFile::Seek}\label{wxtempfileseek}
	90
	91	\func{wxFileOffset}{Seek}{\param{wxFileOffset }{ofs}, \param{wxSeekMode }{mode = wxFromStart}}
	92
	93	Seeks to the specified position.
	94
	95	\membersection{wxTempFile::Tell}\label{wxtempfiletell}
	96
	97	\constfunc{wxFileOffset}{Tell}{\void}
	98
	99	Returns the current position or wxInvalidOffset if file is not opened or if another
	100	error occurred.
	101
	102	\membersection{wxTempFile::Write}\label{wxtempfilewrite}
	103
	104	\func{bool}{Write}{\param{const void }{*p}, \param{size\_t }{n}}
	105
	106	Write to the file, return {\tt true} on success, {\tt false} on failure.
	107
	108	\membersection{wxTempFile::Write}\label{wxtempfilewrites}
	109
	110	\func{bool}{Write}{\param{const wxString\& }{str}, \param{wxMBConv\&}{ conv = wxConvLibc}}
	111
	112	Write to the file, return {\tt true} on success, {\tt false} on failure.
	113
	114	The second argument is only meaningful in Unicode build of wxWidgets when
	115	{\it conv} is used to convert {\it str} to multibyte representation.
	116
	117	\membersection{wxTempFile::Commit}\label{wxtempfilecommit}
	118
	119	\func{bool}{Commit}{\void}
	120
	121	Validate changes: deletes the old file of name m\_strName and renames the new
	122	file to the old name. Returns {\tt true} if both actions succeeded. If {\tt false} is
	123	returned it may unfortunately mean two quite different things: either that
	124	either the old file couldn't be deleted or that the new file couldn't be renamed
	125	to the old name.
	126
	127	\membersection{wxTempFile::Discard}\label{wxtempfilediscard}
	128
	129	\func{void}{Discard}{\void}
	130
	131	Discard changes: the old file contents is not changed, temporary file is
	132	deleted.
	133
	134	\membersection{wxTempFile::\destruct{wxTempFile}}\label{wxtempfiledtor}
	135
	136	\func{}{\destruct{wxTempFile}}{\void}
	137
	138	Destructor calls \helpref{Discard()}{wxtempfilediscard} if temporary file
	139	is still opened.
	140