ExpatParseMgr.h

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//
//


#ifndef EXPATPARSEMGR_H
#define EXPATPARSEMGR_H

#include <stack>
#include <expat.h>
#include <vector>
#include <vapor/MyBase.h>
#include <vapor/common.h>
#ifdef WIN32
#pragma warning(disable : 4251)
#endif

namespace VAPoR {
class ExpatParseMgr;
class XmlNode;
//abstract base class for classes that do xml parsing
class VDF_API ParsedXml {
public:
    virtual ~ParsedXml(){}
    //Callbacks from xml parse
    //Start and end handlers return false on failure.
    virtual bool elementStartHandler(ExpatParseMgr*, int /* depth*/ , std::string& /*tag*/, const char ** /*attribs*/) = 0;
    virtual bool elementEndHandler(ExpatParseMgr*, int /*depth*/ , std::string& /*tag*/) = 0;
    virtual bool charHandler (ExpatParseMgr*, const XML_Char *, int ) {return true;}
    
    //Store previous class for stack
    ParsedXml* previousClass;

protected:
    // known xml attribute values
    //
    static const string _stringType;
    static const string _longType;
    static const string _doubleType;
    static const string _typeAttr;

};
// Structure used for parsing metadata files
//
class VDF_API ExpatStackElement {
    public:
    string tag;         // xml element tag
    string data_type;   // Type of element data (string, double, or long)
    int has_data;       // does the element have data?
    int user_defined;   // is the element user defined?
};
class VDF_API ExpatParseMgr : public VetsUtil::MyBase {
public:

    ExpatParseMgr(ParsedXml* topLevelClass);
 
    ~ExpatParseMgr();

    void parse(ifstream& is);
    ExpatStackElement* getStateStackTop() {return _expatStateStack.top();}
    // Report an XML parsing error
    //
    void parseError(const char *format, ...);
    vector<long>& getLongData() {return _expatLongData;}
    vector<double>& getDoubleData() {return _expatDoubleData;}
    string& getStringData() {return _expatStringData;}
    //Following two methods are to allow different classes to be created during one
    //XML parsing.  These help maintain a stack of classes.
    //When the parsing is to be passed to another class, the original class must call
    //pushClassStack when the xml for the new class is encountered in the startElementHandler.
    
    void pushClassStack(ParsedXml* pc) {
        pc->previousClass = currentParsedClass;
        currentParsedClass = pc;
    }
    ParsedXml* popClassStack(){
        currentParsedClass = currentParsedClass->previousClass;
        return currentParsedClass;
    }

    void skipElement(string tag, int depth);
    
protected:
    ParsedXml* currentParsedClass;
    
    stack<VDF_API ExpatStackElement *> _expatStateStack;

    XML_Parser _expatParser;    // XML Expat parser handle
    string _expatStringData;    // temp storage for XML element character data
    vector <long> _expatLongData;   // temp storage for XML long data
    vector <double> _expatDoubleData;   // temp storage for XML double  data
     

    // known xml attribute values
    //
    static const string _stringType;
    static const string _longType;
    static const string _doubleType;

#ifdef  DEAD
    // XML Expat element handlers
    friend void _StartElementHandler(
        void *userData, const XML_Char *tag, const XML_Char **attrs
    ) {
        ExpatParseMgr* mgr = (ExpatParseMgr *) userData;
        mgr->_startElementHandler(tag, attrs);
    }


    friend void _EndElementHandler(void *userData, const XML_Char *tag) {
        ExpatParseMgr* mgr = (ExpatParseMgr *) userData;
        mgr->_endElementHandler(tag);
    }

    friend void _CharDataHandler(
        void *userData, const XML_Char *s, int len
    ) {
        ExpatParseMgr* mgr = (ExpatParseMgr *) userData;
        mgr->_charDataHandler(s, len);
    }

#else
    // XML Expat element handlers
    friend void _StartElementHandler(
        void *userData, const XML_Char *tag, const XML_Char **attrs
    );


    friend void _EndElementHandler(void *userData, const XML_Char *tag);

    friend void _CharDataHandler(
        void *userData, const XML_Char *s, int len
    );

#endif
    void _startElementHandler(const XML_Char *tag, const char **attrs);
    void _endElementHandler(const XML_Char *tag);
    void _charDataHandler(const XML_Char *s, int len);

    
    //Function pointers that handle custom parsing
private:
    bool _skipFlag;
    string _skipTag;
    int _skipDepth;

};


};

#endif  //  EXPATPARSEMGR_H