Running JavaScript downloaded with XMLHttpRequest recursively

Question

Is it possible to change this code, so it will work recursively if the http://www.myurl.com redirect to the js file that should run?

function include(scriptUrl)
{
        var xmlhttp = new XMLHttpRequest();
        xmlhttp.open("GET", scriptUrl);
        xmlhttp.onreadystatechange = function()
        {
            if ((xmlhttp.status == 200) && (xmlhttp.readyState == 4))
            {
                eval(xmlhttp.responseText);
            }
        };
        xmlhttp.send();
}
include("http://www.myurl.com");

No, this is done automatically, see http://stackoverflow.com/q/282429/1048572 — Bergi, Aug 29 '12 at 11:14

score 2 · Answer 1 · answered Aug 29 '12 at 11:11

2

Why not just do:

$("head").append("<script src='http://myurl.com' type='text/javascript'></script>");

Of course you can do it without jquery but that's the jist of it. If you're just pulling from a URL that only requires GET arguments (if any at all) then it's easier (and safer) to just add a new script element that includes it.

This will also take care of your redirection issue since the browser will follow the redirect.

answered Aug 29 '12 at 11:11

PhonicUK

13,486
4
43
62

The redirect would have been followed with XHR, too, but it is true that a script insertion is better than what the OP tries – Bergi Aug 29 '12 at 11:18
If you are going for jQuery you could consider using [`jQuery.getScript()`](http://api.jquery.com/jQuery.getScript/). – Jasper de Vries Aug 29 '12 at 11:33
Why? Is there some requirement you've not told us about? – PhonicUK Aug 29 '12 at 12:28
Its for pulling data not only js. please read below my comment to Jasper de Vries – Gorden Gram Aug 29 '12 at 12:36
You could still use jQuery for that. Just `eval` the `data` returned by [`jQuery.get()`](http://api.jquery.com/jQuery.get/). – Jasper de Vries Aug 30 '12 at 06:35

Jasper de Vries · Answer 2 · 2012-08-29T13:44:58.487

1

When the URL redirects you to another location it will probably give you a 301 status instead of a 200 status. In that case your check should be:

if ((xmlhttp.status == 200 || xmlhttp.status == 301) && xmlhttp.readyState == 4)

Or you can choose to allow all but the error statuses:

if (xmlhttp.status < 400 && xmlhttp.readyState == 4)

edited Aug 29 '12 at 13:44

answered Aug 29 '12 at 11:07

Jasper de Vries

19,370
6
64
102

It doesn't eval the js when adding this statuses. I tried to add 'else if' for status 301 and then calling include with the new url but after its eval the script (let's say the script is: alert("hello");) its continue to call it again with "www.example.com/alert("hello); for some reason.. any suggests? – Gorden Gram Aug 29 '12 at 12:34
Can you do a `console.log` of `xmlhttp`? Is the status as expected? Do you get a `responseText`? – Jasper de Vries Aug 29 '12 at 12:39
well I don't know why but after including this 'else if' and writing it: ((xmlhttp.status == 301) && (xmlhttp.readyState == 4)) - checking that the state is 4 its working! it didn't work before but who remember what I wrote before :) – Gorden Gram Aug 29 '12 at 13:04

Running JavaScript downloaded with XMLHttpRequest recursively

2 Answers2