draw svg line between elements in array

by John Doe

HTML

<div class="wrap">

    <div class="cont">
      <ul>
    
    <li>ipsum</li>
    <li>doloren</li>
    <li>set</li>
    <li id="c1">lorem</li>
    <li id="c11">amet</li>
  </ul>
  
  <ul>
    <li>ipsum</li>
    <li id="c2">lorem</li>
    <li>doloren</li>
    <li id="c22">amet</li>
    <li>set</li>
    
  </ul>
  <ul>
    <li id="c3">lorem</li>
    <li>ipsum</li>
    <li>doloren</li>
    <li>set</li>
    <li id="c33">amet</li>
  </ul>
   <ul>
    <li>ipsum</li>
    <li id="c4">lorem</li>
    <li>doloren</li>
    <li>set</li>
    <li id="c44">amet</li>
  </ul>
  <p>
    <button class="btn">Összeköt</button>
  </p>
    </div>
  
  <svg id="svg" class="svg">
    <line class="sample"></line>
  </svg>




</div>

CSS

*{
  box-sizing: border-box;
}
p{
  text-align: center;
}
html{
  height: 100%;
}
body {
  min-height: 100%;
  margin: 0;
  background: #20262e;
  padding: 20px 0 0 50px;
  position: relative;
}
.wrap{
  z-index: 100;
}

ul{
  display: inline-block;
  margin: 30px 50px 0 0;
  margin: 0px 50px 0 0;
  padding: 0;
}
ul li {
    display: block;
    list-style-type: none;
    text-align: center;
    padding: 0 10px;
    width: 100px;
    margin-bottom: 20px;
    height: 50px;
    line-height: 50px;
    background-color: #ffffff;
    border: 2px solid #0000002b;
    color: #000000;
    font-weight: bold;
    font-family: arial;
    text-shadow: 1px 1px 2px #ffffffad;
    border-radius: 5px;
    font-size: 12px;
    box-shadow: 1px 2px 4px 0px rgba(0, 0, 0, 0);
}


.cont{
    position: relative;
    z-index: 2;
}

.example{
  margin-top: 30px;
  position: relative;
}
.svg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

JavaScript

function drawSvgLine(t,color){
	var i = 0;
  $(t).each(function(){
  	if( i < t.length - 1 ){
    	if($(t[i]).length && $(t[i+1]).length){
      	var e1= $(t[i]);
        var e2= $(t[i+1]);
        var x1 = $(e1).offset().left + $(e1).outerWidth();
        var y1 = $(e1).offset().top + ($(e1).outerHeight()/2);
        var x2 = $(e2).offset().left;
        var y2 = $(e2).offset().top + ($(e1).outerHeight()/2);
        $('#svg .sample').clone().removeClass('sample').attr('x1',x1).attr('y1',y1).attr('x2',x2).attr('y2',y2).attr('stroke',color).insertAfter($('#svg .sample'));
      }
      i++;
  }
  
  });
  
}

$('.btn').click(function(){
	drawSvgLine(['#c1','#c2','#c3','#c4'],'#64b448');
  drawSvgLine(['#c11','#c22','#c33','#c44'],'#b9f');
	//drawSvgLine('.e1', '.e2');
})