Question

我目前正在尝试创建一个小型应用，该应用从公共交通API获取信息。我创建了一些代表该对象的类，其中一些（此处为Route）包含异步方法。我不知道如何正确调用它们，并不断在它们上遇到TypeError。

这是我的测试脚本：

import { TagHelper } from './modules/TagHelper';

function testMod() {
    TagHelper.getRouteInfo("C1")
        .then(C1 => C1.loadPatterns())
        .then(C1 => C1.loadStops())
        .then(C1 => console.log(C1))
    ;
}

testMod();

这是我的助手模块：

import requestPromise = require('request-promise');

class Route {
    readonly id: string;
    readonly shortName: string;
    readonly longName: string;
    readonly mode: string;
    readonly color: number;
    readonly agencyName: string;
    patterns: Pattern[];
    stops: Stop[];

    constructor(id: string, shortName: string, longName: string, mode: string, color: string, agencyName: string) {
        this.id = id;
        this.shortName = shortName;
        this.longName = longName;
        this.mode = mode;
        this.color = parseInt(color, 16);
        this.agencyName = agencyName;
    }

    async loadPatterns() {
        console.log("TEST");
        this.patterns = JSON.parse(await requestPromise("https://data.metromobilite.fr/otp/routers/default/index/routes/" + this.id + "/patterns"));
        return this;
    }

    async loadStops() {
        this.stops = JSON.parse(await requestPromise("https://data.metromobilite.fr/otp/routers/default/index/routes/" + this.id + "/stops"));
        return this;
    }
}

class Pattern {
    ...
}

class Stop {
    ...
}

const TagHelper = {

    getRouteInfo: async function(route_short_name: string, route_mode: string = null): Promise<Route> {
        const routes_data: Route[] = JSON.parse(await requestPromise("https://data.metromobilite.fr/otp/routers/default/index/routes"));
        for(let route of routes_data) {
            if (route.shortName.toUpperCase() === route_short_name.toUpperCase() && (route_mode === null || route_mode.toUpperCase() === route.mode.toLocaleUpperCase()))
                return route;
        }
        return null;
    }
};

export { TagHelper, Route, Pattern, Stop };

编辑：我只是意识到我没有包括该错误，所以这里是：

(node:868) UnhandledPromiseRejectionWarning: TypeError: C1.loadPatterns is not a function
    at temp.ts:5:24

Answer 1

事实证明，我只是混淆了JSON对象和类实例。感谢estus指出了这一点！

我通过修改Route类来纠正我的错误：

class Route {
    ...
    patterns: Pattern[];
    stops: Stop[];

    constructor(id: string, shortName: string, longName: string, mode: string, color: string, agencyName: string) {
        ...
        this.patterns = [];
        this.stops = [];
    }

    async loadPatterns() {
        for (let pattern of JSON.parse(await requestPromise("https://data.metromobilite.fr/otp/routers/default/index/routes/" + this.id + "/patterns"))) {
            this.patterns.push(new Pattern(pattern.id, pattern.desc));
        }
        return this;
    }

    async loadStops() {
        for (let stop of JSON.parse(await requestPromise("https://data.metromobilite.fr/otp/routers/default/index/routes/" + this.id + "/stops"))) {
            this.stops.push(new Stop(stop.bind, stop.code, stop.name, stop.lat, stop.lon, stop.cluster));
        }
        return this;
    }
}

在promise链中调用异步方法时，获取“ TypeError：X不是函数”

1 个答案: