var stratify = d3.stratify().id(function (d) {return d.name;}).parentId(function(d){return d.parent;});
var rawData=[
    {name:"Eve",parent:""},
    {name:"Cain",parent:"Eve"},
    {name:"Seth",parent:"Eve"},
    {name:"Enos",parent:"Seth"},
    {name:"Noam",parent:"Seth"},
    {name:"Abel",parent:"Eve"},
    {name:"Awan",parent:"Eve"},
    {name:"Enoch",parent:"Awan"},
    {name:"Azura",parent:"Eve"}
];
var data = stratify(rawData);

//扩展d3
(function () {
    function d3_functor(v) {
        return typeof v === "function" ? v : function() {
            return v;
        };
    }
    d3.functor = d3_functor;
    //贝塞尔曲线连接起始和终止点
    function _diagonal() {
        var source = function (d, i) {return d.source;},
                target = function (d, i) {return d.target;}, data=null,
                projection = function (d) {return [ d.x, d.y ];};
        function diagonal(d, i) {
            var p0 = source.call(this, d, i), p3 = target.call(this, d, i), m = (p0.y + p3.y) / 2, p = [ p0, {
                x: p0.x,
                y: m
            }, {
                x: p3.x,
                y: m
            }, p3 ];
            p = p.map(projection);
            return "M" + p[0] + "C" + p[1] + " " + p[2] + " " + p[3];
        }
        diagonal.source = function(x) {
            if (!arguments.length) return source;
            source = d3_functor(x);
            return diagonal;
        };
        diagonal.target = function(x) {
            if (!arguments.length) return target;
            target = d3_functor(x);
            return diagonal;
        };
        diagonal.projection = function(x) {
            if (!arguments.length) return projection;
            projection = x;
            return diagonal;
        };
        return diagonal;
    }
   var __proto__=d3.constructor.prototype;
    __proto__.diagonal=__proto__.diagonal || function () {
                return _diagonal();
            };
}());

var diagonal = d3.diagonal().projection(function (d) {return [d.y,d.x]});
g.selectAll(".link")
        .data(data.descendants().slice(1))//过滤掉root
        .enter().append("path")
        .attr("class", "link")
        .attr("d", function(d) {
            return diagonal({source:{x:d.x,y:d.y},target:{x:d.parent.x,y:d.parent.y}});
        });

var node = g.selectAll(".node")
        .data(data.descendants())
        .enter().append("g")
        .attr("class", function(d) { return "node" + (d.children ? " node--internal" : " node--leaf"); })
        .attr("transform", function(d) { return "translate(" + d.y + "," + d.x + ")"; });
node.append("circle")
        .attr("r", 3);

node.append("text")
        .attr("dy", 3)
        .attr("x", function(d) { return d.children ? -8 : 8; })
        .style("text-anchor", function(d) { return d.children ? "end" : "start"; })
        .text(function(d) { return d.id; });