X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/3660fc40ad00d17d21bf0057a30c099179b6eae8..afbe906abdf9aa69a56571b8b20b095351dd8f34:/docs/latex/wx/htparser.tex diff --git a/docs/latex/wx/htparser.tex b/docs/latex/wx/htparser.tex index a403848a38..91dd28305d 100644 --- a/docs/latex/wx/htparser.tex +++ b/docs/latex/wx/htparser.tex @@ -3,13 +3,12 @@ % htmlparser.tex at 14/Mar/99 20:13:37 % - \section{\class{wxHtmlParser}}\label{wxhtmlparser} -This class handles {\bf generic} parsing of HTML document : it scans +This class handles the {\bf generic} parsing of HTML document: it scans the document and divide it into blocks of tags (where one block consists of begining and ending tag and of text between these -2 tags). +two tags). It is independent from wxHtmlWindow and can be used as stand-alone parser (Julian Smart's idea of speech-only HTML viewer or wget-like utility - @@ -19,14 +18,18 @@ It uses system of tag handlers to parse the HTML document. Tag handlers are not staticaly shared by all instances but are created for each wxHtmlParser instance. The reason is that the handler may contain document-specific temporary data used during parsing (e.g. complicated -structures like tables) +structures like tables). -Typically the user calls only \helpref{Parse}{wxhtmlparserparse} method. +Typically the user calls only the \helpref{Parse}{wxhtmlparserparse} method. \wxheading{Derived from} wxObject +\wxheading{Include files} + + + \wxheading{See also} \helpref{Cells Overview}{cells}, @@ -35,157 +38,221 @@ wxObject \latexignore{\rtfignore{\wxheading{Members}}} - \membersection{wxHtmlParser::wxHtmlParser}\label{wxhtmlparserwxhtmlparser} \func{}{wxHtmlParser}{\void} Constructor. +\membersection{wxHtmlParser::AddTag}\label{wxhtmlparseraddtag} -\membersection{wxHtmlParser::SetFS}\label{wxhtmlparsersetfs} +\func{void}{AddTag}{\param{const wxHtmlTag\& }{tag}} -\func{void}{SetFS}{\param{wxFileSystem }{*fs}} +This may (and may not) be overwriten in derived class. -Sets the virtual file system that will be used to request additional -files. (For example {\tt } tag handler requests wxFSFile with the -image data.) +This method is called each time new tag is about to be added. +{\it tag} contains information about the tag. (See \helpref{wxHtmlTag}{wxhtmltag} +for details.) + +Default (wxHtmlParser) behaviour is this: +First it finds a handler capable of handling this tag and then it calls +handler's HandleTag method. + +\membersection{wxHtmlParser::AddTagHandler}\label{wxhtmlparseraddtaghandler} + +\func{virtual void}{AddTagHandler}{\param{wxHtmlTagHandler }{*handler}} + +Adds handler to the internal list (\& hash table) of handlers. This +method should not be called directly by user but rather by derived class' +constructor. + +This adds the handler to this {\bf instance} of wxHtmlParser, not to +all objects of this class! (Static front-end to AddTagHandler is provided +by wxHtmlWinParser). + +All handlers are deleted on object deletion. + +\membersection{wxHtmlParser::AddText}\label{wxhtmlparseraddword} + +\func{virtual void}{AddWord}{\param{const char* }{txt}} + +Must be overwriten in derived class. + +This method is called by \helpref{DoParsing}{wxhtmlparserdoparsing} +each time a part of text is parsed. {\it txt} is NOT only one word, it is +substring of input. It is not formatted or preprocessed (so white spaces are +unmodified). + +\membersection{wxHtmlParser::DoParsing}\label{wxhtmlparserdoparsing} + +\func{void}{DoParsing}{\param{int }{begin\_pos}, \param{int }{end\_pos}} + +\func{void}{DoParsing}{\void} + +Parses the m\_Source from begin\_pos to end\_pos-1. +(in noparams version it parses whole m\_Source) + +\membersection{wxHtmlParser::DoneParser}\label{wxhtmlparserdoneparser} + +\func{virtual void}{DoneParser}{\void} + +This must be called after DoParsing(). \membersection{wxHtmlParser::GetFS}\label{wxhtmlparsergetfs} \constfunc{wxFileSystem*}{GetFS}{\void} Returns pointer to the file system. Because each tag handler has -reference to it's parent parser it can easily request the file by +reference to it is parent parser it can easily request the file by calling \begin{verbatim} wxFSFile *f = m_Parser -> GetFS() -> OpenFile("image.jpg"); \end{verbatim} +\membersection{wxHtmlParser::GetProduct}\label{wxhtmlparsergetproduct} -\membersection{wxHtmlParser::Parse}\label{wxhtmlparserparse} +\func{virtual wxObject*}{GetProduct}{\void} -\func{wxObject*}{Parse}{\param{const wxString\& }{source}} +Returns product of parsing. Returned value is result of parsing +of the document. The type of this result depends on internal +representation in derived parser (but it must be derived from wxObject!). -Proceeds parsing of the document. This is end-user method. You can simply -call it when you need to obtain parsed output (which is parser-specific) +See wxHtmlWinParser for details. -The method does these things: +\membersection{wxHtmlParser::GetSource}\label{wxhtmlparsergetsource} -\begin{enumerate} -\item calls \helpref{InitParser(source)}{wxhtmlparserinitparser} -\item calls \helpref{DoParsing}{wxhtmlparserdoparsing} -\item calls \helpref{GetProduct}{wxhtmlparsergetproduct} -\item calls \helpref{DoneParser}{wxhtmlparserdoneparser} -\item returns value returned by GetProduct -\end{enumerate} +\func{wxString*}{GetSource}{\void} + +Returns pointer to the source being parsed. -You shouldn't use InitParser, DoParsing, GetProduct or DoneParser directly. \membersection{wxHtmlParser::InitParser}\label{wxhtmlparserinitparser} \func{virtual void}{InitParser}{\param{const wxString\& }{source}} -Setups the parser for parsing the {\it source} string. (Should be overriden +Setups the parser for parsing the {\it source} string. (Should be overridden in derived class) +\membersection{wxHtmlParser::OpenURL}\label{wxhtmlparseropenurl} -\membersection{wxHtmlParser::DoneParser}\label{wxhtmlparserdoneparser} +\func{virtual wxFSFile*}{OpenURL}{\param{wxHtmlURLType }{type}, \param{const wxString\& }{url}} -\func{virtual void}{DoneParser}{\void} - -This must be called after DoParsing(). +Opens given URL and returns {\tt wxFSFile} object that can be used to read data +from it. This method may return NULL in one of two cases: either the URL doesn't +point to any valid resource or the URL is blocked by overriden implementation +of {\it OpenURL} in derived class. +\wxheading{Parameters} -\membersection{wxHtmlParser::DoParsing}\label{wxhtmlparserdoparsing} +\docparam{type}{Indicates type of the resource. Is one of +\begin{twocollist}\itemsep=0pt +\twocolitem{{\bf wxHTML\_URL\_PAGE}}{Opening a HTML page.} +\twocolitem{{\bf wxHTML\_URL\_IMAGE}}{Opening an image.} +\twocolitem{{\bf wxHTML\_URL\_OTHER}}{Opening a resource that doesn't fall into +any other category.} +\end{twocollist}} -\func{void}{DoParsing}{\param{int }{begin\_pos}, \param{int }{end\_pos}} +\docparam{url}{URL being opened.} -\func{void}{DoParsing}{\void} +\wxheading{Notes} -Parses the m\_Source from begin\_pos to end\_pos-1. -(in noparams version it parses whole m\_Source) +Always use this method in tag handlers instead of {\tt GetFS()->OpenFile()} +because it can block the URL and is thus more secure. -\membersection{wxHtmlParser::GetProduct}\label{wxhtmlparsergetproduct} +Default behaviour is to call \helpref{wxHtmlWindow::OnOpeningURL}{wxhtmlwindowonopeningurl} +of the associated wxHtmlWindow object (which may decide to block the URL or +redirect it to another one),if there's any, and always open the URL if the +parser is not used with wxHtmlWindow. -\func{virtual wxObject*}{GetProduct}{\void} +Returned {\tt wxFSFile} object is not guaranteed to point to {\it url}, it might +have been redirected! -Returns product of parsing. Returned value is result of parsing -of the document. The type of this result depends on internal -representation in derived parser (but it must be derived from wxObject!). +\membersection{wxHtmlParser::Parse}\label{wxhtmlparserparse} -See wxHtmlWinParser for details. +\func{wxObject*}{Parse}{\param{const wxString\& }{source}} +Proceeds parsing of the document. This is end-user method. You can simply +call it when you need to obtain parsed output (which is parser-specific) -\membersection{wxHtmlParser::AddTagHandler}\label{wxhtmlparseraddtaghandler} +The method does these things: -\func{virtual void}{AddTagHandler}{\param{wxHtmlTagHandler }{*handler}} +\begin{enumerate}\itemsep=0pt +\item calls \helpref{InitParser(source)}{wxhtmlparserinitparser} +\item calls \helpref{DoParsing}{wxhtmlparserdoparsing} +\item calls \helpref{GetProduct}{wxhtmlparsergetproduct} +\item calls \helpref{DoneParser}{wxhtmlparserdoneparser} +\item returns value returned by GetProduct +\end{enumerate} -Adds handler to the internal list (\& hash table) of handlers. This -method should not be called directly by user but rather by derived class' -constructor. +You shouldn't use InitParser, DoParsing, GetProduct or DoneParser directly. -This adds the handler to this {\bf instance} of wxHtmlParser not to -all objects of this class!!! (Static front-end to AddTagHandler is provided -by wxHtmlWinParser) -All handlers are deleted on object deletion. -\membersection{wxHtmlParser::GetSource}\label{wxhtmlparsergetsource} +\membersection{wxHtmlParser::PushTagHandler}\label{wxhtmlparserpushtaghandler} -\func{wxString*}{GetSource}{\void} +\func{void}{PushTagHandler}{\param{wxHtmlTagHandler* }{handler}, \param{wxString }{tags}} -Returns pointer to the source being parsed. +Forces the handler to handle additional tags +(not returned by \helpref{GetSupportedTags}{wxhtmltaghandlergetsupportedtags}). +The handler should already be added to this parser. +\wxheading{Parameters} -\membersection{wxHtmlParser::GetTempData}\label{wxhtmlparsergettempdata} +\docparam{handler}{the handler} +\docparam{tags}{List of tags (in same format as GetSupportedTags's return value). The parser +will redirect these tags to {\it handler} (until call to \helpref{PopTagHandler}{wxhtmlparserpoptaghandler}). } -\func{virtual wxList*}{GetTempData}{\void} +\wxheading{Example} -This method returns list of wxObjects that represents -all data allocated by the parser. These can't be freeded -by destructor because they must be valid as long as -GetProduct's return value is valid - the caller must -explicitly call +Imagine you want to parse following pseudo-html structure: \begin{verbatim} -delete (MyParser -> GetTempData()); + + + + + + + + \end{verbatim} -to free the memory (this method always sets the list to delete its contents) +It is obvious that you cannot use only one tag handler for tag. +Instead you must use context-sensitive handlers for inside +and inside . -\wxheading{Example} +This is the preferred solution: -Why is this neccessary? Imagine wxHtmlWinParser : when handling -FONT tag it creates some fonts. These fonts are then used by wxHtmlWindow -to display the text. But wxHtmWinParser object is needed only when parsing -the document - it may be deleted then. But fonts CAN'T be deleted - they -must exist as long as the window is displaying text. +\begin{verbatim} +TAG_HANDLER_BEGIN(MYITEM, "MYITEMS") + TAG_HANDLER_PROC(tag) + { + // ...something... + + m_Parser -> PushTagHandler(this, "PARAM"); + ParseInner(tag); + m_Parser -> PopTagHandler(); + + // ...something... + } +TAG_HANDLER_END(MYITEM) +\end{verbatim} -GetTempData() solves the problem. -\membersection{wxHtmlParser::AddText}\label{wxhtmlparseraddword} +\membersection{wxHtmlParser::PopTagHandler}\label{wxhtmlparserpoptaghandler} -\func{virtual void}{AddWord}{\param{const char* }{txt}} +\func{void}{PopTagHandler}{\void} -Must be overwriten in derived class. +Restores parser's state before last call to +\helpref{PushTagHandler}{wxhtmlparserpushtaghandler}. -This method is called by \helpref{DoParsing}{wxhtmlparserdoparsing} -each time a part of text is parsed. {\it txt} is NOT only one word, it is -substring of input. It is not formatted or preprocessed (so white spaces are -unmodified) - -\membersection{wxHtmlParser::AddTag}\label{wxhtmlparseraddtag} -\func{void}{AddTag}{\param{const wxHtmlTag\& }{tag}} +\membersection{wxHtmlParser::SetFS}\label{wxhtmlparsersetfs} -This may (and may not) be overwriten in derived class. +\func{void}{SetFS}{\param{wxFileSystem }{*fs}} -This method is called each time new tag is about to be added. -{\it tag} contains information about the tag. (See \helpref{wxHtmlTag}{wxhtmltag} -for details.) +Sets the virtual file system that will be used to request additional +files. (For example {\tt } tag handler requests wxFSFile with the +image data.) -Default (wxHtmlParser) behaviour is this : -First it finds a handler capable of handling this tag and then it calls -handler's HandleTag method.