How to clone a group of elements in svg and show the clone in specified coordinate？

Question

SVG

<svg width="200" height="200">
    <g id="group">
        <rect x="10" y="10" width="50" height="20" fill="teal"></rect>
        <circle cx="35" cy="40" r="20" fill="red"></circle>
    </g>

    <circle id="ref_cycle" cx="135" cy="140" r="2" fill="green"></circle>

</svg>

I can use:

var copy = d3.select("#group").clone(true).attr("transform", "translate(20,00)"); 

to have a copy of <g id="group"> and display it in page.

But I want this cloned group red "circle" center align with that "ref_cycle" 's center in SVG, but with out lost the group shape. how I can do this in code?

thanks a lot.

Answer 1

here is working code my side with some comments, in case someone need it.

    var ref_cycle = d3.select("#ref_cycle"); 
        //^ get the reference cycle obj

    var clone_template = d3.select("#group"); 
        //^ get the template obj, for later select and clone use

    var clone_trans_x = ref_cycle.attr("cx") - clone_template.select("#inner-ref").attr("cx");
    var clone_trans_y = ref_cycle.attr("cy") - clone_template.select("#inner-ref").attr("cy");
        // to make select be simple, add an id tag in svg group's <circle id="inner-ref" ></circle> first.
        // do the math on offset of two objects    

    clone_template.clone(true).attr("transform", "translate(" + [clone_trans_x, clone_trans_y] + ")");
       // clone it