javascript - JS is not being executed after ajax call -

i'm calling php script includes js code calling xmlhttprequest.send. unfortunatly javascript code in called php script not being executed.

the calling routine:

var formdata = new formdata(); formdata.append("uploadfilename", file);  var ajax = new xmlhttprequest(); ajax.upload.addeventlistener("progress", progresshandler, false);  ajax.addeventlistener("load", completehandler, false); ajax.addeventlistener("error", errorhandler, false); ajax.addeventlistener("abort", aborthandler, false); ajax.open("post", "mod/intern/uploader_upload_done.php"); ajax.send(formdata); 

any javascript in called script fails, alert() call.

file uploader_upload_done.php:

<?php echo date(); ?> <script>alert("hallo");</script> 

when calling uploader_upload_done.php directly, works should.

what doing wrong?

as understand make ajax call php file, , expect javascript there executed. should take account there difference between making call , opening url directly in browser; means downloading html + css + javascript code, , browser automatically interpreting it. when perform ajax call, asking server execute php code, , after that, downloads rest (html + css + javascript), not interpreting it.

if want execute javascript code being returned php file, embed page doing ajax call. this, can use:

function evaljsfromhtml(html) {   var newelement = document.createelement('div');   newelement.innerhtml = html;    var scripts = newelement.getelementsbytagname("script");   (var = 0; < scripts.length; ++i) {     var script = scripts[i];     eval(script.innerhtml);   } } 

however, using eval can dangerous. author's demo: http://plnkr.co/edit/la7opkrfatgohwcanlrl?p=preview

this function useful when php file returns complete html document (i.e., html file head, body, etc.); gets script tags , executes javascript content.

if php file returns javascript code, can execute directly (again, consider not using eval in production environments). is:

var jscode = doajaxcall(); eval(jscode); 

as suggested other users, consider using communication schema (e.g., json file indicate should executed, instead of passing code executed).