Dynamic link

HTML

<script src="http://d3js.org/d3.v3.min.js"></script>

CSS

svg a text{
    text-decoration: underline;
}

JavaScript

var data = ['a', 'b', 'c'];

var svg = d3.select("body").append("svg")
    .attr({
        xmlns: "http://www.w3.org/2000/svg",
        xlink: "http://www.w3.org/1999/xlink",
        width: 100, 
        height: 300
    })
    .selectAll("a")
    .data(data)
    .enter().append("a")
    .attr({"xlink:href": "#"})
    .on("mouseover", function(d, i){ 
        d3.select(this) 
           .wrap("<a xlink:href \"http://example.com/\"></a>")
            .text("eeeeeeeeeeeeeeeeeee");
    })
    .append("text")
    .attr({x: 10, y: function(d, i){ return i*15+15; }})
    .text(function(d, i){ return d; });