How to set custom http headers when changing iframe src?

You can have the results of an ajax request that has custom headers be set as the content of an iframe like so:

$.ajax({
    type: "GET", 
    url: "https://app.icontact.com/icp/a/",
    contentType: "application/json",
    beforeSend: function(xhr, settings){
            xhr.setRequestHeader("some_custom_header", "foo");},
    success: function(data){
        $("#output_iframe_id").attr('src',"data:text/html;charset=utf-8," + escape(data))
    }
});

This is assuming the iframe is pointing at a cross domain src. It is simpler if everything is on the same domain.

Edit: Maybe try this variation.

$.ajax({
    type: "GET", 
    url: "https://app.icontact.com/icp/a/",
    contentType: "application/json",
    beforeSend: function(xhr, settings){
            xhr.setRequestHeader("some_custom_header", "foo");},
    success: function(data){
        $("#output_iframe_id").attr('src',"https://stackoverflow.com/")
        $("#output_iframe_id").contents().find('html').html(data); 
    }
});