Class FilterKeyHandler

example/filterkey/filterkey.cpp:18–106

// This handler forwards event into an output handler, with filtering the descendent events of specified key.
template <typename OutputHandler>
class FilterKeyHandler {
public:
    typedef char Ch;

    FilterKeyHandler(OutputHandler& outputHandler, const Ch* keyString, SizeType keyLength) : 
        outputHandler_(outputHandler), keyString_(keyString), keyLength_(keyLength), filterValueDepth_(), filteredKeyCount_()
    {}

    bool Null()             { return filterValueDepth_ > 0 ? EndValue() : outputHandler_.Null()    && EndValue(); }
    bool Bool(bool b)       { return filterValueDepth_ > 0 ? EndValue() : outputHandler_.Bool(b)   && EndValue(); }
    bool Int(int i)         { return filterValueDepth_ > 0 ? EndValue() : outputHandler_.Int(i)    && EndValue(); }
    bool Uint(unsigned u)   { return filterValueDepth_ > 0 ? EndValue() : outputHandler_.Uint(u)   && EndValue(); }
    bool Int64(int64_t i)   { return filterValueDepth_ > 0 ? EndValue() : outputHandler_.Int64(i)  && EndValue(); }
    bool Uint64(uint64_t u) { return filterValueDepth_ > 0 ? EndValue() : outputHandler_.Uint64(u) && EndValue(); }
    bool Double(double d)   { return filterValueDepth_ > 0 ? EndValue() : outputHandler_.Double(d) && EndValue(); }
    bool RawNumber(const Ch* str, SizeType len, bool copy) { return filterValueDepth_ > 0 ? EndValue() : outputHandler_.RawNumber(str, len, copy) && EndValue(); }
    bool String   (const Ch* str, SizeType len, bool copy) { return filterValueDepth_ > 0 ? EndValue() : outputHandler_.String   (str, len, copy) && EndValue(); }
    
    bool StartObject() { 
        if (filterValueDepth_ > 0) {
            filterValueDepth_++;
            return true;
        }
        else {
            filteredKeyCount_.push(0);
            return outputHandler_.StartObject();
        }
    }
    
    bool Key(const Ch* str, SizeType len, bool copy) { 
        if (filterValueDepth_ > 0) 
            return true;
        else if (len == keyLength_ && std::memcmp(str, keyString_, len) == 0) {
            filterValueDepth_ = 1;
            return true;
        }
        else {
            ++filteredKeyCount_.top();
            return outputHandler_.Key(str, len, copy);
        }
    }

    bool EndObject(SizeType) {
        if (filterValueDepth_ > 0) {
            filterValueDepth_--;
            return EndValue();
        }
        else {
            // Use our own filtered memberCount
            SizeType memberCount = filteredKeyCount_.top();
            filteredKeyCount_.pop();
            return outputHandler_.EndObject(memberCount) && EndValue();
        }
    }

    bool StartArray() {
        if (filterValueDepth_ > 0) {
            filterValueDepth_++;