BSONDotNotationDump.hpp

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

#ifndef BSONDOTNOTATIONDUMP_HPP_
#define BSONDOTNOTATIONDUMP_HPP_

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

namespace mongotype {

class BSONDotNotationDump : virtual public IBSONRenderer, virtual protected IBSONObjectVisitor {
        Parameters& params;
        deque<string> dotStack;
        function<ostream&()> getOStream; // std::function required to store a closure.

protected: // IBSONObjectVisitor overrides.

        virtual void onParseStart() { }

        virtual void onParseEnd() {     }

        virtual void onObjectStart(const BSONParserStack& stack) {
                if (stack.top().getArrayIndex() >= 0) { // If the object is an element of an array...
                         string s("[");
                         s += to_string(stack.top().getArrayIndex());
                         s += "]"; // Output an array index first.
                         dotStack.push_back(s);
                }
        }

        virtual void onObjectEnd(const BSONParserStack& stack) {
                if (stack.top().getArrayIndex() >= 0) { // If the object is an element of an array...
                        dotStack.pop_back();
                }
        }

        virtual void onArrayStart(const BSONParserStack& stack) {
                string s(".");
                s += stack.top().getArray().fieldName();
                 dotStack.push_back(s);
        }

        virtual void onArrayEnd(const BSONParserStack& stack) {
                dotStack.pop_back();
        }

        virtual void onElement(const BSONParserStack& stack) {
                const BSONElement& element = stack.top().getElement();
                BSONTypeFormatter type(params, element);
                string acc;
                for (string s: dotStack) {
                        acc += s;
                }
                acc += '.';
                acc += string(element);
                acc += " ";
                acc += type.to_string();
                getOStream() << acc << "\n";
        }

public: // User Interface

        BSONDotNotationDump(Parameters& pparams, string& initialToken) :
                params(pparams) {
                dotStack.clear();
                dotStack.push_back(initialToken);
        };

        virtual ~BSONDotNotationDump() {};

        /*
         * \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";
                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 /* BSONDOTNOTATIONDUMP_HPP_ */