Polyfill cross-domain XHRs

[danwdart]

In IE < 10 cross-domain XHRs need a different object loading (XDomainRequest, which doesn't work for sync calls) like this for instance:

if (-1 != navigator.userAgent.indexOf('MSIE') && -1 == navigator.userAgent.indexOf('MSIE 1')) { // IE < 10 var x = new XDomainRequest(); x.timeout = 2000; x.onload = function() { return success(x.responseText, scope); } x.onerror = x.ontimeout = function() { return failure(scope); } x.open('GET', url); x.send(); }

Is it possible that this could be integrated?

Cheers

[jonathantneal]

We could certainly do our best. Would you setup a working and failing example?

[danwdart]

Sure, so an example of XHR failing in ie9?

[danwdart]

This for example will error in <= IE9 and work in other browsers:

var x = new XMLHttpRequest(); x.open('GET', 'https://api.github.com/', true); x.onreadystatechange = function() { if (4 == x.readyState) { if (200 == x.status) { // Do what you want with x.responseText } else { // Do what you want with your failure callback } } }

however this will work in IE8/9:

var x = new XDomainRequest(); x.onload = function() { // Do what you want with x.responseText return success(x.responseText); } x.onerror = x.ontimeout = function() { // Do what you want with your failure callback } x.open('GET', 'https://api.github.com/'); x.send();

[defunctzombie]

I am -1 on polyfilling xhr. Too many complications IMO. On Feb 27, 2014 2:39 PM, "Dan Dart" notifications@github.com wrote:

This for example will error in <= IE9 and work in other browsers:

var x = new XMLHttpRequest(); x.open('GET', 'https://api.github.com/', true); x.onreadystatechange = function() { if (4 == x.readyState) { if (200 == x.status) { // Do what you want with x.responseText } else { // Do what you want with your failure callback } } }

however this will work in IE8/9:

var x = new XDomainRequest(); x.onload = function() { // Do what you want with x.responseText return success(x.responseText); } x.onerror = x.ontimeout = function() { // Do what you want with your failure callback } x.open('GET', 'https://api.github.com/'); x.send();

Reply to this email directly or view it on GitHubhttps://github.com/jonathantneal/polyfill/issues/55#issuecomment-36282021 .

[jonathantneal]

If @dandart’s code works just as well if not better than our current XMLHttpRequest polyfill, I’ll all for adding it.

[paulirish]

crossdomain XHR is not terribly common nor is it a piece of cake. you're already setting up CORS headers. asking the developer to bring their own IE polyfill seems reasonable.

[triblondon]

@dandart this thread seems suitably contentious that I haven't raised it against the new service. If you are still keen to have it please consider raising it yourself here: https://github.com/Financial-Times/polyfill-service