WebKit "Refused to set unsafe header "content-length"
- by Paul
I am trying to implement simple xhr abstraction, and am getting this warning when trying to set the headers for a POST. I think it might have something to do with setting the headers in a separate js file, because when i set them in the <script> tag in the .html file, it worked fine. The POST request is working fine, but I get this warning, and am curious why. I get this warning for both content-length and connection headers, but only in WebKit browsers (Chrome 5 beta and Safari 4). In Firefox, I don't get any warnings, the Content-Length header is set to the correct value, but the Connection is set to keep-alive instead of close, which makes me think that it is also ignoring my setRequestHeader calls and generating it's own. I have not tried this code in IE. Here is the markup & code:
test.html:
<!DOCTYPE html>
<html>
<head>
<script src="jsfile.js"></script>
<script>
var request = new Xhr('POST', 'script.php', true, 'data=somedata', function(data) {
console.log(data.text);
});
</script>
</head>
<body>
</body>
</html>
jsfile.js:
function Xhr(method, url, async, data, callback) {
var x;
if(window.XMLHttpRequest) {
x = new XMLHttpRequest();
x.open(method, url, async);
x.onreadystatechange = function() {
if(x.readyState === 4) {
if(x.status === 200) {
var data = {
text: x.responseText,
xml: x.responseXML
};
callback.call(this, data);
}
}
}
if(method.toLowerCase() === "post") {
x.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
x.setRequestHeader("Content-Length", data.length);
x.setRequestHeader("Connection", "close");
}
x.send(data);
} else {
// ... implement IE code here ...
}
return x;
}