Question

首先，我不知道我是否在这里使用了正确的术语，所以事先做了很大的道歉。我会尽力解释我想要做的事情。

我有什么

我有一个返回以下内容的对象：

  var upload = {
          created: "21/07/2017",
          name: "album photo name",
          progress:100,
          url:"www.url.com/photo.jpg"
        }

我正在尝试使用其中一个对象中的URL值来执行数据库更新

  var myList = {
          albumtitle: title,
          albumDate: date,
          album_photo_url: upload.url
        }

执行数据库更新时，控制台会记录：

错误：未捕获（在承诺中）：错误：Firebase.update失败：第一个参数容器在属性'album.jdslakjdlkas.sjdlkajsd.album_photo_url'中未定义

问题我使用的语法是否正确？当我删除album_photo_url行时，其他数据正确上传。或者如果我写：

album_photo_url:upload

然后，所有内容都会使用嵌套节点上传到数据库，该节点包含上传进度，名称，日期和URL。如何访问对象引用中的URL？

这里的任何帮助都会受到广泛赞赏。

修改这是我的完整代码段：

import { Injectable } from '@angular/core';
// import { AngularFire, AngularFireDatabase, FirebaseListObservable } from 'angularfire2';
import { Upload } from './upload';
import { AngularFireDatabase, FirebaseListObservable, FirebaseObjectObservable } from 'angularfire2/database';
import * as firebase from 'firebase';
import { AuthService } from '../../auth.service';


@Injectable()
export class UploadService {

  constructor(private db: AngularFireDatabase, private authService: AuthService) { }

  private basePath: string = '/site_photo';

  uploads: FirebaseListObservable<Upload[]>;


  getUploads(query = {}) {
    this.uploads = this.db.list(this.basePath, {
      query: query
    });
    return this.uploads
  }




  submitForm(title: string, date: string, upload: Upload) {
    this.authService.user.subscribe(user => {
      if (user) {

        console.log(upload.url);

        // The User ID of the current user
        var userId = user.uid;


        // Data to be added to the 'Album' node
        var projectsDetails = {
          albumTitle: title,
          albumDate: reference,
          album_photo_url: upload.url
        }

        // Data to be added to the 'Album List' node
        var projectsList = {
        albumTitle: title,
          albumDate: reference,
          album_photo_url: upload.url
        }



        // Generate a new firebase key to be used for the Project, Project List and Project Member nodes
        var newPostKey = firebase.database().ref().child('album_list').push().key;

        // Create a reference to the firebase storage
        const storageRef = firebase.storage().ref();
        const uploadTask = storageRef.child('site_photo/' + user.uid + '/' + newPostKey + '/site_photo').put(upload.file);


        // Group the updates to the associated firebase nodes
        var updates = {};
        updates['/album/' + user.uid + '/' + newPostKey] = projectsDetails;
        updates['/album_list/' + user.uid + '/' + newPostKey] = projectsList;







        uploadTask.on(firebase.storage.TaskEvent.STATE_CHANGED,
          (snapshot) => {
            // upload in progress
            upload.progress = (snapshot.bytesTransferred / snapshot.totalBytes) * 100
          },
          (error) => {
            // upload failed
            console.log(error)
          },
          () => {
            // upload success
            upload.url = uploadTask.snapshot.downloadURL
            upload.name = upload.file.name
            this.saveToRealtimeDatabase(updates);
          }
        );

      }

    });


  }

  private saveToRealtimeDatabase(updates) {    
    // Perform an atomic Multi-Path update
    return firebase.database().ref().update(updates);
  }


}

Answer 1

var myList = {
    albumtitle: title,
    albumDate: date
}

myList.album_photo_url = upload.url;

Answer 2

上传对象似乎缺少url变量，在创建新对象之前检查“upload”实际上是否包含url。

使用您提供的有限代码很难给出更好的答案。这两个对象是否在同一范围内？

从干净的控制台来看，你提供的语法绝对没有问题。

在另一个对象中使用对象值

2 个答案: