多级嵌套请求

要求以 省 > 市 > 区 > 终端 的顺序获取终端数据

getAllProvince() {return new Promise((resolve) &＃61;> {this.http.get(this.rootUrl &＃43; &＃39;/place/getprovince&＃39;).subscribe((data: any) &＃61;> {resolve(data)})})}// Promise.all &＃43; map 循环 &＃43; Promise 请求循环数据getAllCity(province) {return Promise.all(province.map(province &＃61;> {return new Promise(resolve &＃61;> {this.http.get(this.rootUrl &＃43; &＃39;/place/getcity&＃39;, {params: {pId: province.id,teidstr: this.teids},}).subscribe((data: any) &＃61;> {resolve(data)})})}))}getAllArea(city) {return Promise.all(city.map(city &＃61;> {return new Promise(resolve &＃61;> {this.http.get(this.rootUrl &＃43; &＃39;/place/getarea&＃39;, {params: {pId: city.pId,cId: city.id,teidstr: this.teids},}).subscribe((data: any) &＃61;> {resolve(data)})})}))}getAllTeminal(area) {return Promise.all(area.map(area &＃61;> {return new Promise(resolve &＃61;> {this.http.get(this.rootUrl &＃43; &＃39;/terminal/getall&＃39;, {params: {pId: area.pId,cId: area.cId,aId: area.id,teidstr: this.teids},}).subscribe((data: any) &＃61;> {resolve(data)})})}))}async getAll(callback) {let province: any &＃61; await this.getAllProvince() // 省let city: any &＃61; await this.getAllCity(province) // 市let area: any &＃61; await this.getAllArea(...city) // 区let teminal: any &＃61; await this.getAllTeminal(...area) // 终端callback(province, city, area, teminal)}