BSONObjectTypeDump.hpp

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//----------------------------------------------------------------------------

#ifndef BSONOBJECTTYPEDUMP_HPP_
#define BSONOBJECTTYPEDUMP_HPP_

#include <mongotype.hpp>
#include <Parameters.hpp>
#include <IBSONRenderer.hpp>
#include <BSONTypeFormatter.hpp>
#include <BSONObjectParser.hpp>

namespace mongotype {

class BSONObjectTypeDump : virtual public IBSONRenderer, virtual protected IBSONObjectVisitor {
        Parameters& params;
        string indentStr;
        string initialToken;
        int level;
        function<ostream&()> getOStream; // std::function required to store a closure.

        string istr() {
                string s;
                for (int i=0; i<level; i++) {
                        s += indentStr;
                }
                return s;
        }

protected: // IBSONObjectVisitor overrides.

        virtual void onParseStart() {
                level = 0; // Reset the indent level to zero.
        }

        virtual void onParseEnd() {     }

        virtual void onObjectStart(const BSONParserStack& stack) {
                getOStream() << "\n" << istr(); // Output a newline and indent.
                if (stack.top().getArrayIndex() >= 0) { // If the object is an element of an array...
                        getOStream() << "[" << stack.top().getArrayIndex() << "]: "; // Output an array index first.
                }
                getOStream() << "{"; // Output the opening bracket for the object.
                level++; // Increase the indent for the object's BSON elements.
        }

        virtual void onObjectEnd(const BSONParserStack& stack) {
                level--; // Decrease the indent level after the object's elements.
                getOStream() << "\n" << istr() << "}"; // Output a newline, indent, and bracket closing the object.

        }

        virtual void onArrayStart(const BSONParserStack& stack) {
                getOStream() << " {ARRAY[" << stack.top().getArrayCount() << "]}"; // Output the count of array elements.
                level++; // Increase the indent for the array's BSON elements.
        }

        virtual void onArrayEnd(const BSONParserStack& stack) {
                level--; // Decrease the indent after the array's BSON elements.
        }

        virtual void onElement(const BSONParserStack& stack) {
                const BSONElement& element = stack.top().getElement();
                BSONTypeFormatter type(params, element);
                getOStream() << "\n" << istr() << element << " " << type; // Output newline, indent, element text, element type text.
        }

public: // User Interface

        BSONObjectTypeDump(Parameters& pparams, string& pinitialToken, const char *pindentStr = " ") :
                params(pparams), indentStr(pindentStr), initialToken(pinitialToken), level(0) {}

        virtual ~BSONObjectTypeDump() {};

        /*
         * \param[in] os The output stream to which the object(s) are rendered.
         */
        virtual void setOutputStream(std::ostream& os) {
                getOStream = [&] () -> ostream& { return os; }; // Wrap closure around ostream.
        }

        /*
         * \param[in] prefix The string to be output before the object is rendered, or NULL.
         */
        virtual void begin(const char* prefix) {
                if (prefix != NULL) {
                        getOStream() << prefix;
                }
        }

        /*
         * \param[in] suffix The string to be output after the object is rendered, or NULL.
         */
        virtual void end(const char* suffix) {
                if (suffix != NULL) {
                        getOStream() << suffix;
                }
        }

        virtual void render(const BSONObj& object, int docIndex, int docCount) {
                getOStream() << "\n" << initialToken << " =>";
                BSONObjectParser objectParser(*this); // Construct a parser around this event handler.
                objectParser.parse(object);     // Parse the object and write the text output the the output stream.
        }
};

} /* namespace mongotype */
#endif /* BSONOBJECTTYPEDUMP_HPP_ */