[Solved]-How to determine if D3 tree node falls outside SVG container-d3.js

I didn't look too closely at the linked question or your current calculations. Instead, I think the calculations can be simplified to:

function getElementCoords(element) {      
  // translate on node
  var trans = d3.transform(d3.select(element).attr('transform')).translate,
      // transform on parent "zoom" container
      transFormParent = d3.transform(d3.select(element.parentNode).attr('transform')),
      // translate on zoom container
      transParent = transFormParent.translate,
      // scale on zoom container
      scaleParent = transFormParent.scale,
      // final position of node
      pos = {
        x: trans[0] + transParent[0]/scaleParent[0],
        y: trans[1] + transParent[1]/scaleParent[1]
      };

    return pos;
}

Call it as:

function click(d) {
  console.log(getElementCoords(this));
}

Updated fiddle.

EDITS

@Christian pointed out in the comments, my math was off, should have been:

function getElementCoords(element) {      
  // translate on node
  var trans = d3.transform(d3.select(element).attr('transform')).translate,
      // transform on parent "zoom" container
      transFormParent = d3.transform(d3.select(element.parentNode).attr('transform')),
      // translate on zoom container
      transParent = transFormParent.translate,
      // scale on zoom container
      scaleParent = transFormParent.scale,
      // final position of node
      pos = {
        x: trans[0] * scaleParent[0] + transParent[0], 
        y: trans[1] * scaleParent[1] + transParent[1]
      };

    return pos;
}