///////////////////////////////////////////////////////////////////////////// // Name: htmlparser.h // Purpose: wxHtmlParser class (generic parser) // Author: Vaclav Slavik // Copyright: (c) 1999 Vaclav Slavik // Licence: wxWindows Licence ///////////////////////////////////////////////////////////////////////////// #ifndef __HTMLPARSER_H__ #define __HTMLPARSER_H__ #ifdef __GNUG__ #pragma interface #endif #include "wx/defs.h" #if wxUSE_HTML #include #include class wxHtmlParser; class wxHtmlTagHandler; //-------------------------------------------------------------------------------- // wxHtmlParser // This class handles generic parsing of HTML document : it scans // the document and divide it into blocks of tags (where one block // consists of starting and ending tag and of text between these // 2 tags. //-------------------------------------------------------------------------------- class WXDLLEXPORT wxHtmlParser : public wxObject { DECLARE_ABSTRACT_CLASS(wxHtmlParser) protected: wxString m_Source; // source being parsed wxHtmlTagsCache *m_Cache; // tags cache, used during parsing. wxHashTable m_HandlersHash; wxList m_HandlersList; // handlers that handle particular tags. The table is accessed by // key = tag's name. // This attribute MUST be filled by derived class otherwise it would // be empty and no tags would be recognized // (see wxHtmlWinParser for details about filling it) // m_HandlersHash is for random access based on knowledge of tag name (BR, P, etc.) // it may (and often does) contain more references to one object // m_HandlersList is list of all handlers and it is guaranteed to contain // only one reference to each handler instance. wxFileSystem *m_FS; // class for opening files (file system) public: wxHtmlParser() : wxObject(), m_HandlersHash(wxKEY_STRING) {m_FS = NULL; m_Cache = NULL;} virtual ~wxHtmlParser(); void SetFS(wxFileSystem *fs) {m_FS = fs;} // Sets the class which will be used for opening files wxFileSystem* GetFS() const {return m_FS;} wxObject* Parse(const wxString& source); // You can simply call this method when you need parsed output. // This method does these things: // 1. call InitParser(source); // 2. call DoParsing(); // 3. call GetProduct(); (it's return value is then returned) // 4. call DoneParser(); virtual void InitParser(const wxString& source); // Sets the source. This must be called before running Parse() method. virtual void DoneParser(); // This must be called after Parse(). void DoParsing(int begin_pos, int end_pos); inline void DoParsing() {DoParsing(0, m_Source.Length());}; // Parses the m_Source from begin_pos to end_pos-1. // (in noparams version it parses whole m_Source) virtual wxObject* GetProduct() = 0; // Returns product of parsing // Returned value is result of parsing of the part. The type of this result // depends on internal representation in derived parser // (see wxHtmlWinParser for details). virtual void AddTagHandler(wxHtmlTagHandler *handler); // adds handler to the list & hash table of handlers. wxString* GetSource() {return &m_Source;} virtual wxList* GetTempData() {return NULL;} // 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 delete MyParser -> GetTempData() to free // the memory // (this method always sets the list to delete its contents) protected: virtual void AddText(const char* txt) = 0; // Adds text to the output. // This is called from Parse() and must be overriden in derived classes. // txt is not guaranteed to be only one word. It is largest continuous part of text // (= not broken by tags) // NOTE : using char* because of speed improvements virtual void AddTag(const wxHtmlTag& tag); // Adds tag and proceeds it. Parse() may (and usually is) called from this method. // This is called from Parse() and may be overriden. // Default behavior is that it looks for proper handler in m_Handlers. The tag is // ignored if no hander is found. // Derived class is *responsible* for filling in m_Handlers table. }; //-------------------------------------------------------------------------------- // wxHtmlTagHandler // This class (and derived classes) cooperates with wxHtmlParser. // Each recognized tag is passed to handler which is capable // of handling it. Each tag is handled in 3 steps: // 1. Handler will modifies state of parser // (using it's public methods) // 2. Parser parses source between starting and ending tag // 3. Handler restores original state of the parser //-------------------------------------------------------------------------------- class WXDLLEXPORT wxHtmlTagHandler : public wxObject { DECLARE_ABSTRACT_CLASS(wxHtmlTagHandler) protected: wxHtmlParser *m_Parser; public: wxHtmlTagHandler() : wxObject () {m_Parser = NULL;}; virtual void SetParser(wxHtmlParser *parser) {m_Parser = parser;} // Sets the parser. // NOTE : each _instance_ of handler is guaranteed to be called // only by one parser. This means you don't have to care about // reentrancy. virtual wxString GetSupportedTags() = 0; // Returns list of supported tags. The list is in uppercase and // tags are delimited by ','. // Example : "I,B,FONT,P" // is capable of handling italic, bold, font and paragraph tags virtual bool HandleTag(const wxHtmlTag& tag) = 0; // This is hadling core method. It does all the Steps 1-3. // To process step 2, you can call ParseInner() // returned value : TRUE if it called ParseInner(), // FALSE etherwise protected: void ParseInner(const wxHtmlTag& tag) {m_Parser -> DoParsing(tag.GetBeginPos(), tag.GetEndPos1());} // parses input between beginning and ending tag. // m_Parser must be set. }; #endif // __HTMLPARSER_H__ #endif