django csrftoken ajax

// AJAX请求，获取csrftoken$.ajaxSetup({    beforeSend: function(xhr, settings) {        function getCookie(name) {            var cookieValue = null;            if (document.cookie && document.cookie !== '') {                var cookies = document.cookie.split(';');                for (var i = 0; i < cookies.length; i++) {                    var cookie = jQuery.trim(cookies[i]);                    // Does this cookie string begin with the name we want?                    if (cookie.substring(0, name.length + 1) == (name + '=')) {                        cookieValue = decodeURIComponent(cookie.substring(name.length + 1));                        break;                    }                }            }            return cookieValue;        }        function csrfSafeMethod(method) {            // these HTTP methods do not require CSRF protection            return (/^(GET|HEAD|OPTIONS|TRACE)$/.test(method));        }        if (!csrfSafeMethod(settings.type) && !this.crossDomain) {            var csrftoken = getCookie('csrftoken');            xhr.setRequestHeader("X-CSRFToken", csrftoken);        }    }});