从Firebase存储下载JSON文件 [英] Download json file from firebase storage

问题描述

让我重申一下我的问题.我有一个vue.js应用，可将json文件上传到Firebase存储区中的存储桶.我需要下载要在我的应用中使用的文件，但是当我尝试从Firebase存储下载json文件时，系统显示未捕获(承诺)未定义".错误.

Let me restate my question. I have a vue.js app that uploads a json file to a bucket in my firebase storage. I need to download the file to use in my app but when I try to download a json file from firebase storage I get a "Uncaught (in promise) undefined" error.

我想做的就是将文件下载回一个对象，以便在我的应用中使用

What I would like to do is download the file back into an object to use in my app

这是我下载和读取文件的代码:

Here is my code to download and read the file:

const storage = firebase.storage()
const storageRef = storage.ref()
const objectRef = storageRef.child('BUCKET/FILE_NAME.json')
objectRef.download(function (err, contents) {
    if (!err) {
        var jsObject = JSON.parse(contents.toString('utf8'))
        console.log('jsObject ', jsObject)
    }
})

更新:这是我的全部代码.我检查数据库是否有正在学习的课程.如果找到了，我想从存储中获取该课程，并从其内容中构建对象.

UPDATE: Here is my entire code. I check the DB for an active course. If found, I want to grab that course from storage and built out my object from its contents.

getActiveCourse({ dispatch }, { cid, user }) {
    return new Promise((res, rej) => {
        let userActiveCourse = []
        let archivedUserCourses = []
        let currentCourseRef = db.collection('currentcourses')
        currentCourseRef = currentCourseRef.where('cid', '==', cid)
        currentCourseRef = currentCourseRef.where('user', '==', user.uid)
        currentCourseRef.get().then(snapshot => {
            if (!snapshot.empty) {
                snapshot.forEach(doc => {
                    let course = doc.data()
                    course.id = doc.id
                    if (course.status == 'active') {

                        // WE FOUND AN ACTIVE COURSE. NOW LETS DOWNLOAD IT AND READ IT INTO AN ARRAY
                        const storage = firebase.storage()
                        const storageRef = storage.ref()
                        const objectRef = storageRef.child('BUCKET/FILE_NAME.json')
                        objectRef.download(function (err, contents) {
                                 if (!err) {
                                     var jsObject = JSON.parse(contents.toString('utf8'))
                                 }
                             })
                        userActiveCourse.push(course.course)
                    } else {
                        archivedUserCourses.push(course.course)
                    }
                })
            }

        }).then(() => {
            dispatch('addUserActiveCourse', userActiveCourse)
            dispatch('addArchivedUserCourses', archivedUserCourses)

            res()
        }).catch(() => rej())
    })
},

推荐答案

以下是任何需要此类问题帮助的人的解决方案.

Here was the solution for anyone else needing help with this type of issue.

const storage = firebase.storage()
const storageRef = storage.ref()
const objectRef = storageRef.child(course.storageRef)
objectRef.getDownloadURL().then((url) => {
    axios.get(url).then((response) => {
        let activeCourse = response.data
        userActiveCourse.push(activeCourse)
    })
})

这篇关于从Firebase存储下载JSON文件的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！