I am developing collapsible tree graph. I am trying to generate mouse over event on node. When i mouse over on node at that time it should display name of node. I tried but i don't know how to calculate transform attribute value to show name above or below the node.
var nodeEnter = node.enter().append("g")
      .attr("class", "node")
      .attr("transform", function(d) { return "translate(" + source.y0 + "," + source.x0 + ")"; })
      .on("click", click)
      .on("mouseover", function(d){
            alert("over");
        d3.select(this).attr('transform', function(d){ return 'translate(?,?)'})
        .text(d.name + ": " + d.id)
        .style('display', null);
      })
      .on("mouseout", function(d){ alert("out"); d3.select(this).style('display', 'none'); });
translate(?,?)
collapsible tree graph link : http://bl.ocks.org/mbostock/4339083
Please try to help me Thanks
 
    