如何将多个文件上传到Firebase？

Question

有没有办法将多个文件上传到Firebase存储。它可以在单次尝试中上传单个文件，如下所示。

fileButton.addEventListener('change', function(e){ 
//Get file
var file = e.target.files[0];

//Create storage reference
var storageRef = firebase.storage().ref(DirectryPath+"/"+file.name);

//Upload file
var task = storageRef.put(file);

//Update progress bar
  task.on('state_changed',
    function progress(snapshot){

        var percentage = snapshot.bytesTransferred / snapshot.totalBytes * 100;
        uploader.value = percentage;
    },
    function error(err){

    },
    function complete(){
        var downloadURL = task.snapshot.downloadURL;

    }
  );

});

如何将多个文件上传到Firebase存储。

Answer 1

我找到了上述问题的解决方案，我想把它放在这里因为它对任何人都有用。

//Listen for file selection
fileButton.addEventListener('change', function(e){ 
    //Get files
    for (var i = 0; i < e.target.files.length; i++) {
        var imageFile = e.target.files[i];

        uploadImageAsPromise(imageFile);
    }
});

//Handle waiting to upload each file using promise
function uploadImageAsPromise (imageFile) {
    return new Promise(function (resolve, reject) {
        var storageRef = firebase.storage().ref(fullDirectory+"/"+imageFile.name);

        //Upload file
        var task = storageRef.put(imageFile);

        //Update progress bar
        task.on('state_changed',
            function progress(snapshot){
                var percentage = snapshot.bytesTransferred / snapshot.totalBytes * 100;
                uploader.value = percentage;
            },
            function error(err){

            },
            function complete(){
                var downloadURL = task.snapshot.downloadURL;
            }
        );
    });
}

Answer 2

Firebase存储使用Promise，因此您可以使用Promises来实现它。

这是关于这个主题的firebase博客文章：Keeping our Promises (and Callbacks)

---

给Promise.all（）一个“承诺数组”

Promise.all(
  // Array of "Promises"
  myItems.map(item => putStorageItem(item))
)
.then((url) => {
  console.log(`All success`)
})
.catch((error) => {
  console.log(`Some failed: `, error.message)
});

上传每个文件并返回Promise

putStorageItem(item) {
  // the return value will be a Promise
  return firebase.storage().ref("YourPath").put("YourFile")
  .then((snapshot) => {
    console.log('One success:', item)
  }).catch((error) => {
    console.log('One failed:', item, error.message)
  });
}

YourPath和YourFile可以携带myItems阵列（因此item对象）。

为了便于阅读，我在这里省略了它们，但是你得到了这个概念。

Answer 3

我相信有一个更简单的解决方案：

// set it up
firebase.storage().ref().constructor.prototype.putFiles = function(files) { 
  var ref = this;
  return Promise.all(files.map(function(file) {
    return ref.child(file.name).put(file);
  }));
}

// use it!
firebase.storage().ref().putFiles(files).then(function(metadatas) {
  // Get an array of file metadata
}).catch(function(error) {
  // If any task fails, handle this
});

Answer 4

        let ad_images=["file:///data/user/0/..../IMG-20181216-WA00001.jpg",
                       "file:///data/user/0/..../IMG-20181216-WA00002.jpg",
                       "file:///data/user/0/..../IMG-20181216-WA00003.jpg"];
        let firebase_images=[];

        const ref = firebase.firestore().collection('ads').doc(newRecord.id);
        putStorageItem = (url,index,ext) => {
            return firebase.storage().ref('YOURFOLDER/'+ index +'.'+ext ).putFile(url)
            .then((snapshot) => {
                console.log(snapshot)
                firebase_images[index] = snapshot.downloadURL;              
                //OR
                //firebase_images.push(snapshot.downloadURL);
            }).catch((error) => {
                console.log('One failed:', error.message)
            });
        }

        Promise.all(
            ad_images.map( async (item,index) => {
                let ext = item.split('/').pop().split(".").pop();
                console.log(newRecord.id, item, index, ext);
                await putStorageItem(newRecord.id, item, index, ext);
            })
        )
        .then((url) => {
            console.log(`All success`);
            console.log(firebase_images);
        })
          .catch((error) => {
            console.log(`Some failed: `, error.message)
        });