signaturePad.js

  function createSignaturePads() {
    var elems=document.querySelectorAll("*[id^='signaturePad-']");
   [].forEach.call(elems,function(elem){
     console.log(elem)
        var oldId=elem.getAttribute("id");
        console.log(oldId)
        var oldId=new SignaturePad
        (document.getElementById(oldId))
      });
  }