type OpenXmlElement = class
public
    function Create(_node: XmlNode);overload;
    function Create(_parent: tslobj; _prefix: string; _local_name: string);overload;
    function Init();virtual;
    function InitNode(_node: XmlNode);virtual;
    function Copy(_obj: tslobj);virtual;

    function Deserialize();
    function Serialize();
    function Marshal(): tableArray;
    function GetOrCreateNode(_obj: tslobj);
    function GetNode(): XmlNode;
    function Elements(): array of tslobj;
    function Attributes(): array of OpenXmlAttribute;
    function Xmlns(_prefix: string): string;

public
    function AppendChild(_obj: tslobj); // OpenXmlElement or OpenXmlPcdata
    function InsertAfter(_obj: tslobj; _pos_obj: tslobj);
//     function InsertBefore(_pos_obj: tslobj; _obj: tslobj);
//     function PrependChild(_obj: tslobj);
//     function RemoveChild(_obj: tslobj);
//     function SetAttribute(_obj: OpenXmlAttribute);

public
    LocalName: string; // 本地名称
    [weakref]Parent: tslobj; // 父类
    Prefix: string; // 前缀
    XmlNode: XmlNode; // XMLNode节点
    ElementName: string;

protected
    attributes_: array of OpenXmlAttribute; // 属性
    attributes_pf_: tableArray;
    // child_elements_: array of tslobj; // 子节点元素
    sorted_child_: tableArray;
    container_: TSOfficeContainer;
    xmlns_: tableArray;
end;

function OpenXmlElement.Create(_node: XmlNode);overload;
begin
    node_name := _node.GetName();
    pos := Pos(":", node_name);
    if pos then {self.}Create(nil, node_name[:pos-1], node_name[pos+1:]);
    else {self.}Create(nil, nil, node_name);
    {self.}InitNode(_node);
    xmlns_ := array();
end;

function OpenXmlElement.Create(_parent: tslobj; _prefix: string; _local_name: string);overload;
begin
    {self.}Parent := _parent;
    {self.}Prefix := _prefix;
    {self.}LocalName := _local_name;
    {self.}XmlNode := nil;
    {self.}ElementName := ifString({self.}Prefix) and {self.}Prefix <> "" ? format("%s:%s", {self.}Prefix, {self.}LocalName) : {self.}LocalName;
    {self.}Init();
    xmlns_ := array();
end;

function OpenXmlElement.InitNode(_node: XmlNode);virtual;
begin
    {self.}XmlNode := _node;
    if not _node then return;
    tslassigning_backup := tslassigning;
    tslassigning := 1;
    node := _node.FirstChild();
    while ifObj(node) do
    begin
        node_name := node.GetName();
        arr := sorted_child_[node_name];
        if ifarray(arr) then
        begin
            pf := arr[1];
            obj := pf.Do();
            obj.InitNode(node);
        end
        node := node.NextElement();
    end
    tslassigning := tslassigning_backup;
end;

function OpenXmlElement.GetOrCreateNode(_obj: tslobj);
begin
    if not ifObj({self.}XmlNode) then {self.}XmlNode := {self.}Parent.GetOrCreateNode(self);
    nearest_node := nil;
    child_elements := container_.Get();
    for k, v in child_elements do
    begin
        if ifObj(v.XmlNode) then nearest_node := v.XmlNode;
        if v = _obj then
        begin
            if ifObj(v.XmlNode) then return v.XmlNode;
            if ifnil(nearest_node) then return {self.}XmlNode.InsertFirstChild("element", _obj.ElementName);
            else return {self.}XmlNode.InsertAfterChild(nearest_node, "element", _obj.ElementName);
        end
    end
    raise "No child.";
end;

function OpenXmlElement.GetNode(): XmlNode;
begin
    if not ifObj({self.}XmlNode) then {self.}XmlNode := {self.}Parent.GetOrCreateNode(self);
    return {self.}XmlNode;
end;

function OpenXmlElement.Deserialize();
begin
    if not ifObj({self.}XmlNode) then return;
    attrs := {self.}XmlNode.Attributes();
    for k, v in attrs do
    begin
        pos := pos("xmlns", k);
        if pos then
        begin
            xmlns_[k] := k = "xmlns" ? new OpenXmlAttribute("", "xmlns", v) : new OpenXmlattribute("xmlns", k[pos+6:], v);
            continue;
        end
        pf := attributes_pf_[k];
        if ifnil(pf) then continue;
        pf.Do(v);
    end
    child_elements := container_.Get();
    for k, v in child_elements do
        v.Deserialize();
end;

function OpenXmlElement.Serialize();
begin
    // xmlns
    for k, v in xmlns_ do
        {self.}GetNode().SetAttribute(v.ElementName, v.Value);
    // Attributes
    for k, v in attributes_ do
        if not ifnil(v.Value) then {self.}GetNode().SetAttribute(v.ElementName, v.Value);
    // Children
    child_elements := container_.Get();
    for k, v in child_elements do
        v.Serialize();
end;

function OpenXmlElement.Marshal(): tableArray;
begin
    child_elements := container_.Get();
    child_arr := array();
    for k, v in child_elements do
    begin
        arr := array("type": "element", "name": v.ElementName, "attributes": array());
        if v is Class(OpenXmlPcdata) or v is Class(OpenXmlElement) then
        begin
            marshal := v.Marshal();
            if length(marshal["children"]) = 0 and length(marshal["attributes"]) = 0 then continue;
            arr["children"] := marshal["children"];
            arr["attributes"] union= marshal["attributes"];
            child_arr[length(child_arr)] := arr;
        end
        else if v is Class(OpenXmlEmpty) then
        begin
            marshal := v.Marshal();
            if length(marshal) > 0 then child_arr[length(child_arr)] := arr;
        end
        else begin
            echo "error = marshal.\n";
        end
    end

    tmp_arr := array("type": "element", "name": {self.}ElementName, "children": child_arr, "attributes": array());
    for k,v in attributes_ do
    begin
        if not ifnil(v.Value) then tmp_arr["attributes"][v.ElementName] := v.Value;
    end
    return tmp_arr;
end;

function OpenXmlElement.Xmlns(_prefix: string): string;
begin
    k := ifnil(_prefix) ? "xmlns" : "xmlns:" + _prefix;
    if tslassigning then
    begin
        if ifnil(xmlns_[k]) then
            xmlns_[k] := ifnil(_prefix) ? new OpenXmlAttribute("", "xmlns", nil) : new OpenXmlAttribute("xmlns", _prefix, nil);
    end
    return xmlns_[k];
end;

function OpenXmlElement.Elements(): array of tslobj;
begin
    return container_.Get();
end;

function OpenXmlElement.InsertAfter(_obj: tslobj; _pos_obj: tslobj);
begin
    container_.InsertAfter(_obj, _pos_obj);
end;

function OpenXmlElement.AppendChild(_obj: tslobj);
begin
    container_.Append(_obj);
end;