异步等待未按预期运行

Question

我正在尝试在我的节点服务器中执行一个功能，该功能使用cheerio 抓取网络，问题是由于某种原因我的功能没有按预期运行，

控制器：

class ScraperController {
    static async scrapeDwelling(req, res, next) {
        try {
            const dwelling = await ScraperService.getDwelling(req.params.url);
            console.log(dwelling);
            res.send({dwelling});
        } catch (err) {
            next(err);
        }
    }
}

那么我的服务：

static async getDwelling(url) {
    const dwelling = {};
    await request(`https://www.zonaprop.com.ar/propiedades/${url}`, (err, resp, html) => {
        const $ = cheerio.load(html);
        dwelling.type = $('.price-operation', '#article-container').text();
        dwelling.price = $('.price-items', '#article-container').text();
        dwelling.description = $('.section-description', '#article-container').text();
        dwelling.title = $('.title-type-sup > b').text();
        dwelling.location = $('.title-location > b').text();
        const coordinatesHelper = ($('.static-map', '#article-map').attr('src'));
        const coordinates = coordinatesHelper.substring(
            coordinatesHelper.lastIndexOf('markers=') + 8,
            coordinatesHelper.lastIndexOf('&channel')
        );
        dwelling.coordinates = coordinates;
        console.log($('#tab-foto-flickity').find('img').length);
        return dwelling;
    });
    return dwelling;
}

当您看到控制台日志时，由于某种原因，该函数首先返回，然后执行代码。我在控制台中得到了这个：

{}

GET /public-api/scraper/42998731.html 200 6.559 毫秒 - 15

36

Answer 1

request 节点模块不返回承诺，它使用回调函数。您可以像这样手动将您的请求包装在 Promise 中：

static getDwelling(url) {
    return new Promise((resolve, reject) => {
        request(`https://www.zonaprop.com.ar/propiedades/${url}`, (err, resp, html) => {
            if(err) {
                return reject(err);
            }
            resolve(html);
        });
    }).then((html) => {
        const $ = cheerio.load(html);
        const dwelling = {};
        dwelling.type = $('.price-operation', '#article-container').text();
        dwelling.price = $('.price-items', '#article-container').text();
        dwelling.description = $('.section-description', '#article-container').text();
        dwelling.title = $('.title-type-sup > b').text();
        dwelling.location = $('.title-location > b').text();
        const coordinatesHelper = ($('.static-map', '#article-map').attr('src'));
        const coordinates = coordinatesHelper.substring(
            coordinatesHelper.lastIndexOf('markers=') + 8,
            coordinatesHelper.lastIndexOf('&channel')
        );
        dwelling.coordinates = coordinates;
        console.log($('#tab-foto-flickity').find('img').length);
        return dwelling;
    });
}

或者您可以使用像 request-promise-native 这样的库。