X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/704a4b7524e05d7bf4d208eb1b30be9989abef4c..bcf576ccfe754a634034203aa133c02fb5d2f964:/docs/latex/wx/htparser.tex diff --git a/docs/latex/wx/htparser.tex b/docs/latex/wx/htparser.tex index 3724999272..b5a4f47a60 100644 --- a/docs/latex/wx/htparser.tex +++ b/docs/latex/wx/htparser.tex @@ -3,30 +3,33 @@ % 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). +consists of beginning and ending tag and of text between these +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 - -see InetGet sample for example). +see InetGet sample for example). 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 +are not statically 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 +38,229 @@ wxObject \latexignore{\rtfignore{\wxheading{Members}}} - \membersection{wxHtmlParser::wxHtmlParser}\label{wxhtmlparserwxhtmlparser} \func{}{wxHtmlParser}{\void} -Constructor. +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 overwritten 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 overwritten 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} +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 overridden implementation +of {\it OpenURL} in derived class. -This must be called after DoParsing(). +\wxheading{Parameters} +\docparam{type}{Indicates type of the resource. Is one of: -\membersection{wxHtmlParser::DoParsing}\label{wxhtmlparserdoparsing} +\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) +\membersection{wxHtmlParser::PushTagHandler}\label{wxhtmlparserpushtaghandler} -All handlers are deleted on object deletion. +\func{void}{PushTagHandler}{\param{wxHtmlTagHandler* }{handler}, \param{wxString }{tags}} -\membersection{wxHtmlParser::GetSource}\label{wxhtmlparsergetsource} +Forces the handler to handle additional tags +(not returned by \helpref{GetSupportedTags}{wxhtmltaghandlergetsupportedtags}). +The handler should already be added to this parser. -\func{wxString*}{GetSource}{\void} +\wxheading{Parameters} -Returns pointer to the source being parsed. +\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}). } +\wxheading{Example} -\membersection{wxHtmlParser::GetTempData}\label{wxhtmlparsergettempdata} +Imagine you want to parse following pseudo-html structure: -\func{virtual wxList*}{GetTempData}{\void} +\begin{verbatim} + + + + + + + + +\end{verbatim} + +It is obvious that you cannot use only one tag handler for tag. +Instead you must use context-sensitive handlers for inside +and inside . -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 +This is the preferred solution: \begin{verbatim} -delete (MyParser -> GetTempData()); +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} -to free the memory (this method always sets the list to delete its contents) - -\wxheading{Example} -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. +\membersection{wxHtmlParser::PopTagHandler}\label{wxhtmlparserpoptaghandler} -GetTempData() solves the problem. +\func{void}{PopTagHandler}{\void} -\membersection{wxHtmlParser::AddText}\label{wxhtmlparseraddword} +Restores parser's state before last call to +\helpref{PushTagHandler}{wxhtmlparserpushtaghandler}. -\func{virtual void}{AddWord}{\param{const char* }{txt}} -Must be overwriten in derived class. +\membersection{wxHtmlParser::SetFS}\label{wxhtmlparsersetfs} -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) +\func{void}{SetFS}{\param{wxFileSystem }{*fs}} -\membersection{wxHtmlParser::AddTag}\label{wxhtmlparseraddtag} +Sets the virtual file system that will be used to request additional +files. (For example {\tt } tag handler requests wxFSFile with the +image data.) -\func{void}{AddTag}{\param{const wxHtmlTag\& }{tag} +\membersection{wxHtmlParser::StopParsing}\label{wxhtmlparserstopparsing} -This may (and may not) be overwriten in derived class. +\func{void}{StopParsing}{\void} -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.) +Call this function to interrupt parsing from a tag handler. No more tags +will be parsed afterward. This function may only be called from +\helpref{wxHtmlParser::Parse}{wxhtmlparserparse} or any function called +by it (i.e. from tag handlers). -Default (wxHtmlParser) behaviour is this : -First it finds a handler capable of handling this tag and then it calls -handler's HandleTag method.