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);
        }
    }
});