The following line needs to be added to the $http object that is passed:
headers: {'Content-Type': 'application/x-www-form-urlencoded; charset=UTF-8'}
And the data passed should be converted to a URL-encoded string:
> $.param({fkey: "key"})
'fkey=key'
So you have something like:
$http({
method: 'POST',
url: url,
data: $.param({fkey: "key"}),
headers: {'Content-Type': 'application/x-www-form-urlencoded; charset=UTF-8'}
})
From: https://groups.google.com/forum/#!msg/angular/5nAedJ1LyO0/4Vj_72EZcDsJ
UPDATE
To use new services added with AngularJS V1.4, see