从Node.js中的请求函数返回值

Question

我正在设置一个仪表板项目。在这里，我需要一个天气小部件。因此，我创建了一个按城市获取天气的函数。但是我无法在请求函数之外获得该值，因为。我想要它是因为我想将此值存储在数组中并将该数组传递给渲染。 你能帮我吗？

function getWeather(city) {
    let apiKey = '48eb9b6228b51e3445b97cb1640729a1'
    let url = `http://api.openweathermap.org/data/2.5/weather?q=${city}&units=metric&appid=${apiKey}`
    var test = request(url, (err, response, body) => {
        if (err) console.log('error:', error)
        return body.main.temp
    })
    return ""
}

router.get('/dashboard', ensureAuthenticated, (req, res) => {
    //Get the widgets of the user
    var widget
    var widgets = {
        name: "",
        content: "",
        value: ""
    }
    var tabWidgets = []
    //
    if (req.user.local) {
        widget = req.user.local.widgets
    } else if (req.user.facebook) {
        widget = req.user.facebook.widgets
    }
    for (var i = 0; i < widget.length; i++) {
        if (widget[i].name == "weather") {
            widgets.name = widget[i].name
            widgets.content = widget[i].content
            widgets.value = getWeatherFromCity(widgets.content)
            tabWidgets.push(widgets)
        } else if (widget[i].name == "youtube") {
            continue
        } else if (widgets[i].name == "steam") {
            continue
        }
    }
    res.render('dashboard', {
        user: req.user,
        widgets: tabWidgets
    })
})