Refactoring

css_editor.js

/* css_editor.js */

module.exports = function(element,css){
   for(var key in css){
      element.style[key] = css[key];
   } 
}



/* Your file.css*/

var qrcode = require( 'qrcode' );
var setCSS = require('./css_editor.js');

module.exports = function( channel, engine ) {
    // Create a wrapper
    var wrapper = document.createElement( 'div' );
    // Add some style
    setCSS(wrapper,{
     background:'#E0ECF8',
     position:'absolute',
     top:'1px',
     right:'1px',
     zIndex:9999,
     borderRadius:'15px 0px 15px 15px',
     fontSize:'20px',
     fontFamily:'Arial',
     color:'#2E2E2E',
     // For impress.js, or the wrapper won't be clickable
     pointerEvents:'auto'
     });

    // Remove it when you click on it
    wrapper.addEventListener( 'click', function() {
        this.parentNode.removeChild( this );
    }, false );

    // Store the url
    var url = 'http://remoteprez.margaine.com/prez.html?c=' + channel +
        '&e=' + engine;

    // Create a DOM element to show
    var link = document.createElement( 'a' );

    // Add some style
    setCSS(link,{
     display :'block',
     margin:'15px',
     color:'#333',
    });

    link.href = url;
    link.textContent = 'Click here to control your presentation';
    link.target = '_blank';

    // Add it to the wrapper
    wrapper.appendChild( link );

    // Add the "OR"
    var or = document.createElement( 'div' );
    or.textContent = 'or scan this QRcode';
    setCSS(or,{ margin:'5px',
                textAlign:'center'
    });

    wrapper.appendChild( or );

    // Now create the QRCode
    var qr = qrcode( 10, 'M' );
    qr.addData( url );
    qr.make();

    wrapper.innerHTML += qr.createImgTag( 3 );

    var img = wrapper.querySelector( 'img' );
    setCSS(img,{
      margin:'20px auto',
      display:'block' 
    });

    // And a close button
    var close = document.createElement( 'div' );
    close.textContent = 'Close';
    setCSS(close,{
      margin:'5px',
      textAlign:'center',
      cursor:'pointer',
      fontSize:'10px',
      textDecoration:'underline'
    });

    wrapper.appendChild( close );

    // And append it to the body
    document.body.appendChild( wrapper );
};