javascript - Fix JS XML load to not use async=false - how? -

i set out xml parse (single node) using jquery, had no luck ended using plain javascript instead. code found in thread: parse xml using js

now can see way use xmlhttprequest function deprecated , might removed in future, ruin quite lot on homepage xmlhttprequest , google inspector reports

synchronous xmlhttprequest outside of workers in process of being removed web platform has detrimental effects end user's experience

i re-open original question, , rewriting below load xml without using async=false in code

xhttp.open("get",filename,false); 

the code being invoked 9/10 down in hmtl-code, changing "false" "true" no good, nothing loads @ (i guess code moves on before has chance insert xml-data?). weak abilities in js had google find answers points to: w3c on send/get

how change code avoid using "false" statement?

the xml like:

<scoreresults> <topscorepicture>100</topscorepicture> <topscorefeature>100</topscorefeature> <topscoreui>100</topscoreui> <item> <title> <![cdata[ test sample 1 ]]> </title> <link>    somelink    </link> <guid ispermalink="true">   somelink      </guid> <scorepicture>82</scorepicture> <scorefeature>90</scorefeature> <scoreui>85</scoreui> <measurepowerotb>180</measurepowerotb> <measurepowercal>160</measurepowercal> <measurepowerstandby>0.2</measurepowerstandby> <measurecontrastotb>2000</measurecontrastotb> <measurecontrastcal>2200</measurecontrastcal> <measurebrightnessotb>210</measurebrightnessotb> <measurebrightnesscal>130</measurebrightnesscal> </item> </scoreresults> 

the script reads:

function loadxmldoc(filename) { if (window.xmlhttprequest)   {   xhttp=new xmlhttprequest();   } else // code ie5 , ie6   {   xhttp=new activexobject("microsoft.xmlhttp");   } xhttp.open("get",filename,false); xhttp.send(); return xhttp.responsexml; }    function showtvscore(testno) {      //load xml     xmldoc = loadxmldoc("/testscores.xml");      //extract highest score picture     tsp = xmldoc.getelementsbytagname("topscorepicture")[0];     topspvalue = tsp.childnodes[0];      //extract highest score features     tsf = xmldoc.getelementsbytagname("topscorefeature")[0];     topsfvalue = tsf.childnodes[0];      //extract highest score ui     tsui = xmldoc.getelementsbytagname("topscoreui")[0];     topsuivalue = tsui.childnodes[0];      //extract  picture score specific test no.     sp = xmldoc.getelementsbytagname("scorepicture")[testno];     spvalue = sp.childnodes[0];      //extract feature score specific test no.     sf = xmldoc.getelementsbytagname("scorefeature")[testno];     sfvalue = sf.childnodes[0];      //extract ui score specific test no.     sui = xmldoc.getelementsbytagname("scoreui")[testno];     suivalue = sui.childnodes[0];      //calculate current scores     scorepicture = math.round(number(spvalue.nodevalue) / number(topspvalue.nodevalue) * 100);     scorefeature = math.round(number(sfvalue.nodevalue) / number(topsfvalue.nodevalue) * 100);     scoreui = math.round(number(suivalue.nodevalue) / number(topsuivalue.nodevalue) * 100);     scoretotal = math.round(0.5 * scorepicture + 0.25 * scorefeature + 0.25 * scoreui);      //set color of picture scorebar     switch (math.round(scorepicture / 10)) {         case 1:             picturecolor = "#934f00";             break;         case 2:             picturecolor = "#c36900";             break;         case 3:             picturecolor = "#f28200";             break;         case 4:             picturecolor = "c38d00";             break;         case 5:             picturecolor = "#f2af00";             break;         case 6:             picturecolor = "#07abfb";             break;         case 7:             picturecolor = "#008ed3";             break;         case 8:             picturecolor = "#006699";             break;         case 9:             picturecolor = "#00537b";             break;         case 10:             picturecolor = "#003f5d";             break;     };     //set color of feature scorebar     switch (math.round(scorefeature / 10)) {         case 1:             featurecolor = "#934f00";             break;         case 2:             featurecolor = "#c36900";             break;         case 3:             featurecolor = "#f28200";             break;         case 4:             featurecolor = "c38d00";             break;         case 5:             featurecolor = "#f2af00";             break;         case 6:             featurecolor = "#07abfb";             break;         case 7:             featurecolor = "#008ed3";             break;         case 8:             featurecolor = "#006699";             break;         case 9:             featurecolor = "#00537b";             break;         case 10:             featurecolor = "#003f5d";             break;     };     //set color of ui scorebar     switch (math.round(scoreui / 10)) {         case 1:             uicolor = "#934f00";             break;         case 2:             uicolor = "#c36900";             break;         case 3:             uicolor = "#f28200";             break;         case 4:             uicolor = "c38d00";             break;         case 5:             uicolor = "#f2af00";             break;         case 6:             uicolor = "#07abfb";             break;         case 7:             uicolor = "#008ed3";             break;         case 8:             uicolor = "#006699";             break;         case 9:             uicolor = "#00537b";             break;         case 10:             uicolor = "#003f5d";             break;     };     //set color of total scorebar     switch (math.round(scoretotal / 10)) {         case 1:             totalcolor = "#934f00";             break;         case 2:             totalcolor = "#c36900";             break;         case 3:             totalcolor = "#f28200";             break;         case 4:             totalcolor = "c38d00";             break;         case 5:             totalcolor = "#f2af00";             break;         case 6:             totalcolor = "#07abfb";             break;         case 7:             totalcolor = "#008ed3";             break;         case 8:             totalcolor = "#006699";             break;         case 9:             totalcolor = "#00537b";             break;         case 10:             totalcolor = "#003f5d";             break;     };      //construct html     htmlchunkstart = "<div style=\"float: right; text-align: right; width: 40px; font-weight: 500; padding-left: 20px; color: #666;\"><i class=\"fa fa-picture-o\"></i></div><div class=\"progress\" style=\"background-color:#e2e2e2\">";     picturebar = "<div class=\"progress-bar\" role=\"progressbar\" aria-valuenow=\"" + number(spvalue.nodevalue) + "\" aria-valuemin=\"0\" aria-valuemax=\"" + number(topspvalue.nodevalue) + "\" style=\"width:" + scorepicture + "%; background-color:" + picturecolor + ";\">" + scorepicture + "%</div>";     htmlchunk1 = "</div> <div style=\"float: right; text-align: right; width: 40px; font-weight: 500; padding-left: 20px; color: #666;\"><i class=\"fa fa-cogs\"></i></div><div class=\"progress\" style=\"background-color:#e2e2e2\">";     featurebar = "<div class=\"progress-bar\" role=\"progressbar\" aria-valuenow=\"" + number(sfvalue.nodevalue) + "\" aria-valuemin=\"0\" aria-valuemax=\"" + number(topsfvalue.nodevalue) + "\" style=\"width:" + scorefeature + "%; background-color:" + featurecolor + "\">" + scorefeature + "%</div>";     htmlchunk2 = " </div><div style=\"float: right; text-align: right; width: 40px; font-weight: 500; padding-left: 20px; color: #666;\"><i class=\"fa fa-user\"></i></div><div class=\"progress\" style=\"background-color:#e2e2e2\">";     uibar = "<div class=\"progress-bar\" role=\"progressbar\" aria-valuenow=\"" + number(suivalue.nodevalue) + "\" aria-valuemin=\"0\" aria-valuemax=\"" + number(topsuivalue.nodevalue) + "\" style=\"width:" + scoreui + "%; background-color:" + uicolor + ";\">" + scoreui + "%</div>";     htmlchunk3 = "</div> <div style=\"padding-top: 3px;float: right; text-align: right; width: 40px; font-weight: 500; padding-left: 20px; color: #666;\"><i class=\"fa fa-star\"></i></div><div class=\"progress progress-lg\" style=\"background-color:#e2e2e2;height: 30px;\">";     totalbar = "<div class=\"progress-bar progress-bar-info\" role=\"progressbar\" aria-valuenow=\"" + scoretotal + "\" aria-valuemin=\"0\" aria-valuemax=\"100\" style=\"width:" + scoretotal + "%; background-color:" + totalcolor + ";font-size:1.1em;font-weight:600;\">total: " + scoretotal + "%</div></div>";      //write html     document.write(htmlchunkstart + picturebar + htmlchunk1 + featurebar + htmlchunk2 + uibar + htmlchunk3 + totalbar); } 

instead of returning value loadxmldoc, pass callback function.

add readystatechange event handler and, when have loaded data, call function , pass argument.

function loadxmldoc(filename, callback) {   var xhr = new xmlhttprequest();   xhr.open("get", filename);   xhr.onreadystatechange = function () {     if (this.readystate === 4 && this.status === 200) {        callback(this.responsexml);       }   };   xhr.send(); }