TreeXML.h

/*
 
MIT License
 
Copyright (c) 2017 FMI Open Development / Markus Peura, first.last@fmi.fi
 
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
 
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
 
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
 
*/
/*
Part of Rack development has been done in the BALTRAD projects part-financed
by the European Union (European Regional Development Fund and European
Neighbourhood Partnership Instrument, Baltic Sea Region Programme 2007-2013)
*/
/*
 * TreeXML.h
 *
 *  Created on: Jun 24, 2012
 *      Author: mpeura
 */
 
 
 
#ifndef TREE_XML
#define TREE_XML
 
#include <ostream>
 
#include <drain/Sprinter.h>
#include <drain/FlexibleVariable.h>
 
#include "ClassXML.h"
#include "Flags.h"
#include "ReferenceMap.h"
#include "TreeUnordered.h"
 
namespace drain {
 
 
class StyleXML : public ReferenceMap2<FlexibleVariable> {
 
public:
 
    inline
    StyleXML(){};
 
    static const SprinterLayout styleLineLayout;
    static const SprinterLayout styleRecordLayout;
    static const SprinterLayout styleRecordLayoutActual;
 
};
 
 
inline
std::ostream & operator<<(std::ostream &ostr, const StyleXML & style){
    drain::Sprinter::toStream(ostr, style.getMap(), drain::Sprinter::xmlAttributeLayout);
    return ostr;
}
 
class XML : protected ReferenceMap2<FlexibleVariable> {
public:
 
 
    static const int UNDEFINED = 0;
    static const int COMMENT = 1;
    static const int CTEXT = 2;
    static const int STYLE = 3;
    static const int SCRIPT = 4;
 
    typedef ReferenceMap2<FlexibleVariable> map_t;
 
 
    // String, still easily allowing numbers through set("id", ...)
    std::string id;
 
    // Consider either/or
    std::string ctext;
 
    std::string url;
 
    template <class V>
    static inline
    void attribToStream(std::ostream &ostr, const std::string & key, const V &value){
        ostr << ' ' << key << '=' << '"' << value << '"'; // << ' ';
    }
 
    static int nextID;
 
    typedef drain::Path<std::string,'/'> path_t; // consider xml_path_t
    typedef path_t::elem_t path_elem_t;
 
    inline
    static int getCount(){
        return nextID;
    }
 
 
    inline
    void setId(){
        link("id", id);
    }
 
    inline
    void setId(const std::string & s){
        link("id", id = s);
    }
 
    template <char C='\0', typename ...TT>
    inline
    void setId(const TT & ...args) {
        link("id", id = drain::StringBuilder<C>(args...));
    }
 
    inline
    const std::string & getId() const {
        return id;
    }
 
    inline
    bool empty() const {
        return map_t::empty();
    }
 
    inline
    const map_t & getAttributes() const {
        return *this;
    };
 
    // Maybe controversial. Helps importing sets of variables.
    inline
    map_t & getAttributes(){
        return *this;
    };
 
 
    //   But otherways confusing?
    virtual inline
    void setAttribute(const std::string & key, const std::string &value){
        (*this)[key] = value;
    }
 
    //   But otherways confusing?
    virtual inline
    void setAttribute(const std::string & key, const char *value){
        (*this)[key] = value; // -> handleString()
    }
 
    template <class V>
    inline
    void setAttribute(const std::string & key, const V & value){
        (*this)[key] = value; // -> handleString()
    }
 
 
    inline
    void remove(const std::string & s){
        iterator it = this->find(s);
        if (it != this->end()){
            this->erase(it);
        }
    }
 
 
    inline
    const drain::FlexibleVariable & get(const std::string & key) const {
        return (*this)[key];
    }
 
    inline
    drain::FlexibleVariable & get(const std::string & key){
        return (*this)[key];
    }
 
 
    template <class V>
    inline
    V get(const std::string & key, const V & defaultValue) const {
        return map_t::get(key, defaultValue);
    }
 
    inline
    std::string get(const std::string & key, const char * defaultValue) const {
        return map_t::get(key, defaultValue);
    }
 
 
    template <typename ... TT>
    inline
    void addClass(const TT &... args) {
        classList.add(args...);
    }
 
    /*
    template <typename ... TT>
    inline
    void addClass(const std::string & s, const TT &... args) {
        classList.insert(s);
        addClass(args...);
    }
    */
 
    template <class V>
    inline
    bool hasClass(const V & cls) const {
        return classList.has(cls);
    }
 
    inline
    void removeClass(const std::string & s) {
        classList.remove(s);
    }
 
    inline
    void clearClasses(){
        classList.clear();
    }
 
    // ------------------ Style Class ---------------
 
 
    ClassListXML classList;
 
    typedef std::list<path_t> path_list_t;
 
    StyleXML style;
 
 
    //   This could also be in TreeXMLutilities
    template <class V>
    static
    bool findById(const V & tree, const std::string & tag, typename V::path_t & result, const typename V::path_t & path = path_t());
 
 
    //   This could also be in TreeXMLutilities
    template <class V>
    static
    bool findById(const V & tree, const std::string & tag, path_list_t & result, const path_t & path = path_t());
 
    template <class V, class T>
    static
    bool findByTag(const V & tree, const T & tag, path_list_t & result, const path_t & path = path_t());
 
    //   This could also be in TreeXMLutilities
    template <class V, class T>
    static
    bool findByTags(const V & tree, const std::set<T> & tags, path_list_t & result, const path_t & path = path_t());
 
 
    template <class T2, class C>
    static
    bool findByClass(const T2 & t, const C & cls, std::list<path_elem_t> & result);
 
 
    //template <class V, class E>
    template <class V, class C>
    static inline
    bool findByClass(const V & t, const C & cls, path_list_t & result, const path_t & path = path_t());
 
 
 
};
 
 
template <class T=int>
class NodeXML : public XML {
 
public:
 
 
    typedef T elem_t;  // consider xml_elem_t
    elem_t type;
 
    typedef NodeXML<T> xml_node_t;
 
 
    typedef UnorderedMultiTree<NodeXML<T>,false, path_t> xml_tree_t;
 
 
    inline
    NodeXML(const elem_t & t = elem_t(0)){
        type = t;
        drain::StringTools::import(++nextID, id);
        // id = getTag()+id; UNDEF
    };
 
    // Note: use default constructor in derived classes.
    inline
    NodeXML(const NodeXML & node){
        //drain::StringTools::import(++nextID, id);
        copyStruct(node, node, *this, RESERVE); // This may corrupt (yet unconstructed) object?
        type = node.getType();
        drain::StringTools::import(++nextID, id);
        // id = getTag()+id; UNDEF
    }
 
 
    inline
    ~NodeXML(){};
 
 
    typedef std::map<T,std::string> tag_map_t;
 
    static
    tag_map_t tags;
 
 
 
 
    virtual
    void setType(const elem_t &t){
        type = t;
        // in derived classes, eg. drain::image::BaseGDAL
        // warning: case value ‘...’ not in enumerated type
    }
 
    /* Consider this later, for user-defined (not enumerated) tag types.
    virtual
    void setType(const std::string & type);
    */
 
    inline
    const elem_t & getType() const {
        return type;
    };
 
    inline
    bool typeIs(const elem_t &t) const {
        return type == t;
    };
 
    /*
    template <elem_t E>
    inline
    bool typeIs() const {
        return type == E;
    };*/
 
 
    // Consider raising these to XML
    inline
    bool isComment() const {
        return typeIs((elem_t)COMMENT);
    }
 
    inline
    bool isCText() const {
        return typeIs((elem_t)CTEXT);
    }
 
    inline
    bool isUndefined() const {
        return typeIs((elem_t)UNDEFINED);
        //return ((int)getType() == UNDEFINED);
    }
 
// protected:
 
    // virtual
    bool isSelfClosing() const {
 
        static
        const std::set<elem_t> l = {(elem_t)SCRIPT};
        return (l.find(this->getType()) == l.end()); // not in the set
 
        //return false;
    }
 
    // template <int N>
    static inline
    const std::string & getTag(unsigned int index){
        typename tag_map_t::const_iterator it = tags.find((elem_t)index);
        if (it != tags.end()){
            return it->second;
        }
        else {
            // consider empty
            static std::string dummy;
            dummy = drain::StringBuilder<>("UNKNOWN-", index);
            return dummy;
            // throw std::runtime_error(drain::StringBuilder<':'>(__FILE__, __FUNCTION__, " tag [", static_cast<int>(index), "] missing from dictionary"));
        }
    };
 
 
 
    inline
    const std::string & getTag() const {
        return getTag(type); // risky? converts enum to int .. and back.
    };
 
 
 
    // NEW: --------------
 
    inline
    void set(const NodeXML & node){
        if (isUndefined()){
            // Should make sense, and be safe. Esp. when exactly same node type, by templating
            setType(node.getType());
        }
        else if (type == STYLE) {
            drain::Logger mout(__FILE__, __FUNCTION__);
            mout.suspicious("copying STYLE from node: ", node);
        }
        drain::SmartMapTools::setValues<map_t>(getAttributes(), node.getAttributes());
    }
 
    inline
    void set(const elem_t & type){
        setType(type);
    }
 
    inline
    void set(const std::string & s){
        if (type == STYLE){
            SmartMapTools::setValues(style, StringTools::trim(s, "; \t\n"), ';', ':');
            //drain::SmartMapTools::setValues<map_t,true>(getAttributes(), s);
        }
        else {
            setText(s);
        }
    }
 
    inline
    void set(const char *s){
        set(std::string(s));
    }
 
    inline
    void set(const drain::Castable & s){
        setText(s);
    }
 
    inline
    void set(const std::initializer_list<Variable::init_pair_t > &l){
        // TODO: redirect to set(key,value), for consistency
        if (type == STYLE){
            drain::SmartMapTools::setValues(style, l);
        }
        else {
            drain::SmartMapTools::setValues<map_t,true>(getAttributes(), l);       // add new keys
            // drain::SmartMapTools::setValues<map_t,false>((map_t &)*this, l);   // update only
        }
    }
 
    template <class X>
    inline
    void set(const std::map<std::string, X> & args){
        // TODO: redirect to set(key,value), for consistency
        if (type == STYLE){
            drain::SmartMapTools::setValues(style, args);
        }
        else {
            drain::SmartMapTools::setValues<map_t,true>(getAttributes(), args);       // add new keys
            // drain::SmartMapTools::setValues<map_t,false>((map_t &)*this, l);   // update only
        }
    }
 
 
    template <class V>
    inline
    void set(const std::string & key, const V & value){
        if (type == STYLE){
            // Modify collection directly
            setStyle(key, value);
        }
        else if (key == "style"){
            // Modify collection
            setStyle(value);
        }
        else if (key == "class"){
            // mout.warn<LOG_DEBUG>("class");
            std::string cls;
            drain::StringTools::import(value, cls);
            addClass(cls);
        }
        else {
            setAttribute(key, value);
        }
 
    }
 
 
 
    // Check char *
    inline
    NodeXML & operator=(const T & x){
        set(x);
        return *this;
    }
 
    inline
    NodeXML & operator=(const Castable &c){
        setText(c);
        return *this;
    }
 
 
    inline
    NodeXML & operator=(const std::string &s){
        setText(s);
        return *this;
    }
 
    inline
    NodeXML & operator=(const char *s){
        setText(s);
        return *this;
    }
 
    inline
    NodeXML & operator=(const std::initializer_list<std::pair<const char *,const drain::Variable> > &l){
        set(l);
        return *this;
    }
 
 
    inline
    NodeXML & setComment(const std::string & text = "") {
 
        setType((elem_t)COMMENT);
 
        if ((int)getType() != COMMENT){ //cross-check
            throw std::runtime_error(drain::TypeName<NodeXML<T> >::str() + ": COMMENT not supported");
        }
 
        ctext = text;
        return *this;
    }
 
 
    template <class S>
    inline
    //  NodeXML & setText(const std::string & text = "") {
    NodeXML & setText(const S & value) {
        if (isUndefined()){
            setType((elem_t)CTEXT);
            if (!isCText()){ //cross-check
                throw std::runtime_error(drain::TypeName<NodeXML<T> >::str() + ": CTEXT not supported");
            }
        }
        else if (typeIs((elem_t)STYLE)){
            setStyle(value); //
            // SmartMapTools::updateValues(this->style, value, ';', ':');
            //
        }
        drain::StringTools::import(value, ctext);
        return *this;
    }
 
    inline
    NodeXML & setText(const char *value) {
        setText(std::string(value));
        return *this;
    }
 
    // ------------------ Style ---------------
 
 
    template <class S>
    inline
    void setStyle(const S &value){
        drain::Logger mout(__FILE__, __FUNCTION__);
        mout.error("unsupported type ", drain::TypeName<S>::str(), " for value: ", value);
    }
 
    void setStyle(const std::string & value){
        drain::Logger mout(__FILE__, __FUNCTION__);
        if (isUndefined()){
            mout.suspicious("setting style for undefined elem: ", *this);
        }
        else if (type == STYLE){
            mout.warn("setting style for STYLE elem: ", *this);
        }
        SmartMapTools::setValues(style, StringTools::trim(value, "; \t\n"), ';', ':');
    }
 
    void setStyle(const char *value){
        setStyle(std::string(value));
    }
 
    inline
    void setStyle(const std::string & key, const std::string & value){
        // const std::initializer_list<Variable::init_pair_t > &l
        // drain::Logger mout(__FILE__, __FUNCTION__);
        // mout.special<LOG_WARNING>("Spezial str");
        this->style[key] = value;
    }
 
 
 
    template <class V>
    inline
    void setStyle(const std::string & key, const std::initializer_list<V> &l){
        // const std::initializer_list<Variable::init_pair_t > &l
        if (type == STYLE){  // typeIs(STYLE) fails
            drain::Logger mout(__FILE__, __FUNCTION__);
            mout.warn("Setting style of STYLE?  initializer_list<", drain::TypeName<V>::str(), "> = ", sprinter(l)); // , StyleXML::styleLineLayout ?
            //mout.revised<LOG_WARNING>("Element is not STYLE but ", getTag(), ", initializer_list<", drain::TypeName<V>::str(), "> = ", sprinter(l)); // , StyleXML::styleLineLayout ?
        }
        this->style[key] = l;
    }
 
 
 
    template <class V>
    inline
    void setStyle(const std::string & key, const V & value){
        // drain::Logger mout(__FILE__, __FUNCTION__);
        if (type == STYLE){
            drain::Logger mout(__FILE__, __FUNCTION__);
            // "reuse" style map as style record map
            std::stringstream sstr;
            drain::Sprinter::toStream(sstr, value, StyleXML::styleLineLayout);
            mout.warn("Setting style of STYLE?, arg type=", drain::TypeName<V>::str());
            mout.warn("Check results: skipped ", sstr.str());
            mout.warn("Check results: applied ", value);
            this->style[key] = value; //sstr.str();
        }
        else {
            // mout.special<LOG_WARNING>("Spezial ", drain::TypeName<V>::str());
            this->style[key] = value;
        }
    }
 
 
    inline
    void setStyle(const std::initializer_list<std::pair<const char *,const drain::Variable> > &l){
        drain::SmartMapTools::setValues(style, l);
    }
 
 
 
 
 
    template <class V>
    static inline
    std::ostream & docToStream(std::ostream & ostr, const V & tree){
        V::node_data_t::xml_node_t::docTypeToStream(ostr);
        V::node_data_t::xml_node_t::toStream(ostr, tree);
        return ostr;
    }
 
    template <class V>
    static
    std::ostream & toStream(std::ostream &ostr, const V & t, const std::string & defaultTag = "", int indent=0);
 
 
    static // virtual
    inline
    std::ostream & docTypeToStream(std::ostream &ostr){
        ostr << "<?xml ";
        for (const auto & entry: xmldoc_attribs){
            attribToStream(ostr, entry.first, entry.second);
        }
        ostr << "?>";
        ostr << '\n';
        return ostr;
    }
 
    // drain::NodeHTML::HTML
    // typedef std::pair<key_t,xml_node_t> node_pair_t;
    // TODO: where is this needed?
    template <int E>
    static inline
    const std::pair<key_t,NodeXML<T> > & entry(){
        static const elem_t elem = (elem_t)E;
        static const std::pair<key_t,NodeXML<T> > nodeEntry(getTag(E), elem); // note: converts tag (string) to key_t if needed.
        return nodeEntry;
    }
 
 
 
 
 
protected:
 
    typedef std::map<std::string,std::string> xmldoc_attrib_map_t;
 
    static xmldoc_attrib_map_t xmldoc_attribs;
 
    //inline    void addClass(){}
 
 
    // TODO: consider TAG from dict?
    // std::string tag;
 
 
};
 
/*
 
template <class N>
int NodeXML<N>::nextID = 0;
 
template <class T>
const int NodeXML<T>::UNDEFINED(0);
 
template <class T>
const int NodeXML<T>::COMMENT(1);
 
template <class T>
const int NodeXML<T>::CTEXT(2);
 
template <class T>
const int NodeXML<T>::STYLE(3);
 
template <class T>
const int NodeXML<T>::SCRIPT(4);
*/
 
typedef drain::UnorderedMultiTree<NodeXML<>,false, NodeXML<>::path_t> TreeXML;
 
// NOTE: template will not match for subclasses of NodeXML<E> because default template will match any class exactly.
template <class E, bool EX, class P>
struct TypeName< drain::UnorderedMultiTree<NodeXML<E>,EX,P> > {
 
    static const std::string & str(){
        static const std::string name = drain::StringBuilder<>("TreeXML<", TypeName<E>::str(), ">");
        return name;
    }
 
    static const char* get(){
        return str().c_str();
    }
};
 
 
// Experimental.
template <>
TreeXML & TreeXML::addChild(const TreeXML::key_t & key);
 
 
 
//template <class N>
template <class T>
//bool NodeXML<N>::findById(const T & t, const std::string & id, typename T::path_t & result, const typename T::path_t & path){
bool XML::findById(const T & t, const std::string & id, typename T::path_t & result, const typename T::path_t & path){
 
    if (t->id == id){
        result = path;
        return true;
    }
 
    // Recursion
    for (const auto & entry: t){
        if (findById(entry.second, id, result, path_t(path, entry.first))){
            return true;
        }
    }
 
    return false;
    //return !result.empty();
}
 
 
 
// template <class N> NodeXML<N>
template <class T>
bool XML::findById(const T & t, const std::string & id, NodeXML<>::path_list_t & result, const path_t & path){
 
    if (t->id == id){
        result.push_back(path);
    }
 
    for (const auto & entry: t){
        findById(entry.second, id, result, path_t(path, entry.first));
    }
 
    return !result.empty();
}
 
//template <class N>
template <class T, class N>
bool XML::findByTag(const T & t, const N & tag, NodeXML<>::path_list_t & result, const path_t & path){
 
    // const T & t = tree(path);
 
    if (t->typeIs(tag)){
        result.push_back(path);
    }
 
    for (const auto & entry: t){
        findByTag(entry.second, tag, result, path_t(path, entry.first));
    }
 
    //return result;
    return !result.empty();
}
 
//template <class N>
template <class T,class N>
bool XML::findByTags(const T & t, const std::set<N> & tags, NodeXML<>::path_list_t & result, const path_t & path){
 
    // const T & t = tree(path);
 
    //if (t->typeIs(tag)){
    if (tags.count(t->getType()) > 0){
        result.push_back(path);
    }
 
    for (const auto & entry: t){
        findByTags(entry.second, tags, result, path_t(path, entry.first));
    }
 
    //return result;
    return !result.empty();
}
 
 
//template <class N>
// template <class T>
//bool NodeXML<N>::findByClass(const T & t, const std::string & cls, NodeXML<>::path_list_t & result, const path_t & path){
 
template <class T2, class C> // NodeXML<N>
//bool XML::findByClass(const T2 & t, const C & cls, NodeXML<>::path_list_t & result, const path_t & path){
bool XML::findByClass(const T2 & t, const C & cls, XML::path_list_t & result, const path_t & path){
 
    // drain::Logger mout(__FILE__,__FUNCTION__);
 
    if (t->classList.has(cls)){
        result.push_back(path);
    }
 
    for (const auto & entry: t){
        // mout.warn(t->get("name", "<name>"), "... continuing to: ", path_t(path, entry.first));
        findByClass(entry.second, cls, result, path_t(path, entry.first));
    }
 
    return !result.empty();
}
 
// template <class N>
template <class T2, class C> //  NodeXML<N>
bool XML::findByClass(const T2 & t, const C & cls, std::list<path_elem_t> & result){
 
    for (const auto & entry: t){
        if (entry.second->hasClass(cls)){
            result.push_back(entry.first);
        }
    }
 
    return !result.empty();
}
 
 
 
 
template <class N>
inline
std::ostream & operator<<(std::ostream &ostr, const NodeXML<N> & node){
 
    //ostr << node.getTag() << '<' << (unsigned int)node.getType() << '>' << ' ';
    ostr  << '<' << node.getTag() << '>' << ' ';
 
    // drain::Sprinter::toStream(ostr, node.getAttributes(), drain::Sprinter::jsonLayout);
    // drain::Sprinter::toStream(ostr, node.getAttributes().getMap(), drain::Sprinter::jsonLayout);
    //
    if (!node.getAttributes().empty()){
        drain::Sprinter::toStream(ostr, node.getAttributes().getMap(), drain::Sprinter::xmlAttributeLayout);
        ostr << ' ';
    }
    if (!node.classList.empty()){
        //ostr << '['; // has already braces []
        //drain::Sprinter::toStream(ostr, node.classList, drain::Sprinter::pythonLayout);
        drain::Sprinter::toStream(ostr, node.classList, ClassListXML::layout);
        //ostr << ']' << ' ';
        ostr << ' ';
    }
    if (!node.style.empty()){
        ostr << '{';
        drain::Sprinter::toStream(ostr, node.style);
        ostr << '}' << ' ';
    }
    if (!node.ctext.empty()){
        ostr << "'";
        if (node.ctext.length() > 20){
            ostr << node.ctext.substr(0, 15);
        }
        else {
            ostr << node.ctext;
        }
        ostr << "'";
    }
    return ostr;
}
 
 
template <class N>
template <class T>
std::ostream & NodeXML<N>::toStream(std::ostream & ostr, const T & tree, const std::string & defaultTag, int indent){
 
 
    const typename T::container_t & children = tree.getChildren();
 
    // Indent
    //std::fill_n(std::ostream_iterator<char>(ostr), 2*indent, ' ');
    std::string fill(2*indent, ' ');
    ostr << fill;
 
    // Start dag
    if (tree->isComment()){
        ostr << "<!-- " << tree->getTag() << ' ' << tree->ctext; // << " /-->\n";
    }
    else if (tree->isCText()){
        ostr << tree->ctext; // << " /-->\n";
    }
    else if (tree->getTag().empty())
        ostr << '<' << defaultTag; // << ' ';
    else {
        ostr << '<' << tree->getTag(); // << ' ';
        // TODO check GDAL XML
        //if (!defaultTag.empty())
        //  attribToStream(ostr, "name", defaultTag);
    }
 
    if (tree->typeIs((elem_t)STYLE)){
        //ostr << ' ';
        attribToStream(ostr, "data-mode", "experimental");
        // Sprinter::sequenceToStream(ostr, tree->style, StyleXML::styleRecordLayout);
        // ostr << "\n /-->";
    }
    else if (!tree->isCText()){
        //char sep=' ';
        if (!tree->classList.empty()){
            ostr << " class=\"";
            drain::Sprinter::toStream(ostr, tree->classList, ClassListXML::layout);
            // std::copy(tree->classList.begin(), tree->classList.end(), std::ostream_iterator<std::string>(ostr, " "));
            ostr << '"'; //ostr << "\"";
        }
 
        // Iterate attributes - note: also for comment
        // Checking empties, so Sprinter::toStream not applicable
        for (const typename T::node_data_t::key_t & key: tree.data.getKeyList()){
            if (!tree.data[key].empty()){
                std::stringstream sstr;
                sstr << tree.data[key];  // consider checking 0, not only empty string "".
                if (!sstr.str().empty()){
                    attribToStream(ostr, key, sstr.str());
                }
            }
            //ostr << ' ';
        }
 
        // TAG style
        if (!tree->style.empty()){
            ostr << " style=\"";
            Sprinter::sequenceToStream(ostr, tree->style, StyleXML::styleLineLayout);
            //Sprinter::mapToStream(ostr, tree->style, StyleXML::styleLineLayout);
            ostr << '"'; // << ' ';
        }
 
 
    }
    else {
        if (!tree.data.empty()){
            // ??
        }
    }
 
    // END TAG
    if (tree->isComment()){
        ostr << " /-->\n";
    }
    else if (tree->isCText()){
        ostr << '\n';
    }
    else if (tree.data.isSelfClosing() &&
            (!tree->typeIs((elem_t)STYLE)) && (!tree->typeIs((elem_t)SCRIPT)) &&
            (children.empty()) && tree->ctext.empty() ){ // OR no ctext!
        // close TAG
        ostr << "/>\n";
        //ostr << '/' << '>';
        //ostr << '\n';
    }
    else {
        // close starting TAG ...
        ostr << '>';
 
        // ... and write contents
 
        /*
        if (!tree->style.empty()){
            ostr << "<!-- STYLE? ";
            drain::Sprinter::toStream(ostr, tree->style.getMap(), drain::Sprinter::xmlAttributeLayout);
            ostr << "/-->\n";
        }
        */
 
        if (tree->typeIs((elem_t)STYLE)){
            // https://www.w3.org/TR/xml/#sec-cdata-sect
            // ostr << "<![CDATA[ \n";
            if (!tree->ctext.empty()){
                // TODO: indent
                ostr << fill << tree->ctext << " /* CTEXT? */" << '\n';
            }
            if (!tree->getAttributes().empty()){
                ostr << "\n\t /* <!-- DISCARDED attribs ";
                drain::Logger mout(__FILE__,__FUNCTION__);
                mout.warn("STYLE elem contains attributes, probably meant as style: ", tree.data);
                Sprinter::toStream(ostr, tree->getAttributes()); //, StyleXML::styleRecordLayout
                ostr << " /--> */" << '\n';
            }
            if (!tree->style.empty()){
                ostr << fill << "/** style obj **/" << '\n';
                for (const auto & attr: tree->style){
                    ostr << fill << "  ";
                    Sprinter::pairToStream(ostr, attr, StyleXML::styleRecordLayout); // {" :;"}
                    //attr.first << ':' attr.first << ':';
                    ostr << '\n';
                }
                // ostr << fill << "}\n";
                // Sprinter::sequenceToStream(ostr, entry.second->getAttributes(), StyleXML::styleRecordLayoutActual);
                // ostr << '\n';
            }
            ostr << '\n';
            // ostr << fill << "<!-- elems /-->" << '\n';
            ostr << fill << "/* elems */" << '\n';
            for (const auto & entry: tree.getChildren()){
                if (!entry.second->ctext.empty()){
                    //ostr << fill << "<!-- elem("<< entry.first << ") ctext /-->" << '\n';
                    ostr << fill << "  " << entry.first << " {" << entry.second->ctext << "} /* CTEXT */ \n";
                }
                if (!entry.second->getAttributes().empty()){
                    //ostr << fill << "<!-- elem("<< entry.first << ") attribs /-->" << '\n';
                    ostr << fill << "  " << entry.first << " {\n";
                    for (const auto & attr: entry.second->getAttributes()){
                        ostr << fill  << "    ";
                        ostr << attr.first << ':' << attr.second << ';';
                        //Sprinter::pairToStream(ostr, attr, StyleXML::styleLineLayout); // {" :;"}
                        // Sprinter::pairToStream(ostr, attr, StyleXML::styleRecordLayout); // {" :;"}
                        // attr.first << ':' attr.first << ':';
                        ostr << '\n';
                    }
                    ostr << fill << "  }\n";
                    //Sprinter::sequenceToStream(ostr, entry.second->getAttributes(), StyleXML::styleRecordLayoutActual);
                    ostr << '\n';
                }
                // Sprinter::sequenceToStream(ostr, entry.second->style, StyleXML::styleRecordLayout);
            }
            ostr << "\n"; // end CTEXT
            //ostr << " ]]>\n"; // end CTEXT
            // end STYLE defs
        }
        else {
 
            if (tree->ctext.empty())
                ostr << '\n'; // TODO nextline
            else
                ostr << tree->ctext;
 
            for (const auto & entry: children){
                toStream(ostr, entry.second, entry.first, indent+1); // no ++
                //ostr << *it;
            }
            // add end </TAG>
 
        }
 
        if (tree->typeIs((elem_t)STYLE) || !children.empty()){
            ostr << fill;
            //std::fill_n(std::ostream_iterator<char>(ostr), 2*indent, ' ');
        }
 
        ostr << '<' << '/' << tree->getTag() << '>';
        ostr << '\n';  // TODO nextline
 
        //if (tree.data.id >= 0)
        //  ostr << "<!-- " << tree.data.id << " /-->\n";
    }
    return ostr;
}
 
 
 
 
inline
std::ostream & operator<<(std::ostream &ostr, const TreeXML & t){
    // DOC def? TODO: preamble/prologToStream()
    TreeXML::node_data_t::docTypeToStream(ostr); // must be member, to support virtual?
    TreeXML::node_data_t::toStream(ostr, t, "");
    return ostr;
}
 
 
}  // drain::
 
#endif /* TREEXML_H_ */