Codes raises exception '[specific_method] is not defined'

Question

I've got following javascript code. It's simply class, that should receive some data from REST WCF client.

class EmployeesWcfClient {
            constructor(url) {
                if (url == null) {
                    url = "http://localhost:35798/MyCompanyService.svc/";
                }
                this.url = url;
            }


            doGetRequest(relUrl) {
                return $.ajax({
                    type: 'GET',
                    contentType: 'json',
                    dataType: 'json',
                    url: this.url + relUrl,
                    async: false
                });
            }

            doPostRequest(relUrl, data) {
                return $.ajax({
                    type: 'POST',
                    data: JSON.stringify(data),
                    contentType: "application/json; charset=utf-8",
                    dataType: "json",
                    url: this.url + relUrl,
                    async: false
                });
            }

            getEmployees() {
                return doGetRequest('Employees');
            }
        }

And I don't know why it's raises exception: 'doGetRequest is not defined'. Could someone help?

Answer 1

答案很简单： 在'return this.doGetRequest（'Employees'）;'中使用此运算符。在第一个代码示例中，缺少此运算符。

Answer 2

在doGetRequest的ajax中，this.url不会引用EmployeesWcfClient.url，而是指向ajax选项对象本身。所以在调用ajax请求之前请参考这个。

doGetRequest(relUrl) {
   var _this = this;
   return $.ajax({
       type: 'GET',
       contentType: 'json',
       dataType: 'json',
       url: _this.url + relUrl,
       async: false
   });
 }

但我不确定是否返回此ajax函数将完全返回请求中的响应，尽管您已将其设为async: false。更好地使用回调或承诺。