obtiene la cookie, en este caso la xsrf y la envia mediante json

get_cookie.js

function getCookie(name) {
    var r = document.cookie.match("\\b" + name + "=([^;]*)\\b");
    return r ? r[1] : undefined;
}

jQuery.postJSON = function(url, args, callback) {
    args._xsrf = getCookie("_xsrf");
    $.ajax({url: url, data: $.param(args), dataType: "text", type: "POST",
            success: function(response) {
        if (callback) callback(eval("(" + response + ")"));
    }, error: function(response) {
        console.log("ERROR:", response)
    }});
};