load/replace css/js

load_replace_css_js.user.js

// ==UserScript==
// @name load_replace_css_js
// @namespace https://gist.github.com/search?q=thegitfather+UserScript
// @author thegitfather
// @version 0.11
// @description load/replace css/js
// @updateURL https://gist.github.com/thegitfather/679c9bc76e9b058790e3/raw/load_replace_css_js.user.js
// @downloadURL https://gist.github.com/thegitfather/679c9bc76e9b058790e3/raw/load_replace_css_js.user.js
// @include http://127.0.0.1/*
// @grant none
// ==/UserScript==


function loadjscssfile(filename, filetype){
  if (filetype=="js"){ //if filename is a external JavaScript file
    var fileref=document.createElement('script');
    fileref.setAttribute("type","text/javascript");
    fileref.setAttribute("src", filename);
  }
  else if (filetype=="css"){ //if filename is an external CSS file
    var fileref=document.createElement("link");
    fileref.setAttribute("rel", "stylesheet");
    fileref.setAttribute("type", "text/css");
    fileref.setAttribute("href", filename);
  }
  if (typeof fileref!="undefined")
  document.getElementsByTagName("head")[0].appendChild(fileref);
}

function createjscssfile(filename, filetype){
  if (filetype=="js"){ //if filename is a external JavaScript file
    var fileref=document.createElement('script');
    fileref.setAttribute("type","text/javascript");
    fileref.setAttribute("src", filename);
  }
  else if (filetype=="css"){ //if filename is an external CSS file
    var fileref=document.createElement("link");
    fileref.setAttribute("rel", "stylesheet");
    fileref.setAttribute("type", "text/css");
    fileref.setAttribute("href", filename);
  }
  return fileref;
}

function replacejscssfile(oldfilename, newfilename, filetype){
  var targetelement=(filetype=="js")? "script" : (filetype=="css")? "link" : "none"; //determine element type to create nodelist using
  var targetattr=(filetype=="js")? "src" : (filetype=="css")? "href" : "none"; //determine corresponding attribute to test for
  var allsuspects=document.getElementsByTagName(targetelement);
  for (var i=allsuspects.length; i>=0; i--){ //search backwards within nodelist for matching elements to remove
    if (allsuspects[i] && allsuspects[i].getAttribute(targetattr)!==null && allsuspects[i].getAttribute(targetattr).indexOf(oldfilename)!=-1){
      var newelement=createjscssfile(newfilename, filetype);
      allsuspects[i].parentNode.replaceChild(newelement, allsuspects[i]);
    }
  }
}


// usage examples:

//loadjscssfile("http://localhost/myproject/script.js", "js");
//loadjscssfile("http://localhost/myproject/styles.css", "css");
//replacejscssfile("/frontend/default/js/script.js", "http://localhost/myproject/script.js", "js");
//replacejscssfile("/frontend/default/js/styles.css", "http://localhost/myproject/styles.css", "css");