Firebase快速上传多个图像

Question

I want to upload multiple images with some text in firebase when user pushed the button. to do that I implemented for loop. Let's say if user picked 3 photos, then I think firebase should look like this

 "Post": {
    "uid": {
      "Text": "some text",
      "imageUrl": "url",
      "imageUrl2": "url2",
      "imageUrl3": "url3"
    }
  }

But it returns like this. That tweetImageUrl is the third photo's url which is picked last. also inside storage, there is only one photo which is the third photo as well.

How can I upload images correctly? Here is my code.

    func sendTweets() {

         let text = textView.text
         let tweetLength = textView.text.count
         let imagesNumber = imagesArray.count
         format.dateFormat = "yyyy-MM-dd HH:mm"
         let strDate = format.string(from: date as Date)
         let childRef = ref.child("TWEETS").child(uid!).childByAutoId()
         let key = ref.child("TWEETS").child(uid!).childByAutoId().key
         let childStorageRef = storageRef.child("tweetImage").child(uid!).child(key)

  if(tweetLength>0 && imagesNumber>0)
    {

       for image in imagesArray {

        let tweetImage = image
        if let uploadData = UIImagePNGRepresentation(tweetImage) {

         childStorageRef.putData(uploadData, metadata: nil, completion: { (metadata, error) in
                    if error != nil {
                        print("error")
        } else {

        if let imageUrl = metadata?.downloadURL()?.absoluteString {
          let values = ["Text": text!, "tweetImageUrl": imageUrl, "Date": strDate]  as [String : Any]
            childRef.updateChildValues(values)

              }
            }
          })
        }
      }
       dismiss(animated: true, completion: nil)
    }
         else if(tweetLength>0)
         {
            let values = ["Text": text!, "Date": strDate]  as [String : Any]

         childRef.updateChildValues(values)

         dismiss(animated: true, completion: nil)

         }

         else if(imagesNumber>0)
         {

        for image in imagesArray {

            let tweetImage = image
            if let uploadData = UIImagePNGRepresentation(tweetImage) {

             childStorageRef.putData(uploadData, metadata: nil, completion: { (metadata, error) in
                if error != nil {
                    print("error")
                } else {

            if let imageUrl = metadata?.downloadURL()?.absoluteString {
            let values = ["tweetImageUrl": imageUrl, "Date": strDate]  as [String : Any]
            childRef.updateChildValues(values)
                }
             }
          })
        }
      }
        dismiss(animated: true, completion: nil)
  }  else {
        alertTheUser(title: "error", message: "enter something.")
    }
}//func

Also when it comes to retrieve those images and display on the collection view after uploaded, is this proper way to achieve that? Thank you in advance!

Answer 1

I think this is not the right database structure that you should follow while using firebase. If you store images like that say imageurl1, imageurl2..., etc. It would be really difficult to fetch those values without knowing the key for it. I suggest you to follow a structure like

"Post": {
    "uid": {
      "Text": "some text",
      "images": {
         autoID1: url1,
         autoID2: url2
      }
    }
  }

So It would be easy to fetch those URLs

You could append the URLs by using

let postRef = Database.database().reference(withPath: "Post").child(uid).child("images")
let autoID = postRef.childByAutoID().key
postRef.child(autoID).setValue(url)

Answer 2

Thanks to Rozario's help, I figured it out. What I was missing was I didn't declare AutoId inside for-loop. That's why old value was replaced by new value. code below worked as I expected. Node looks like this. hope it would help.

  "Post": {
    "uid": {
      "Text": "some text",
      "images": {
         autoID1: url1,
         autoID2: url2
      }
    }
  }

code below.

func sendTweets() {

             let text = textView.text
             let tweetLength = textView.text.count
             let imagesNumber = imagesArray.count
             format.dateFormat = "yyyy-MM-dd HH:mm"
             let strDate = format.string(from: date as Date)
             let childRef = ref.child("TWEETS").child(uid!).childByAutoId()

      if(tweetLength>0 && imagesNumber>0)
        {

           for image in imagesArray {

            let postRef = childRef.child("tweetImageUrl")
            let autoID = postRef.childByAutoId().key
            let childStorageRef = storageRef.child("Images").child(uid!).child(autoID)
            let tweetImage = image

            if let uploadData = UIImagePNGRepresentation(tweetImage) {

             childStorageRef.putData(uploadData, metadata: nil, completion: { (metadata, error) in
                        if error != nil {
                            print("error")
            } else {

            if let imageUrl = metadata?.downloadURL()?.absoluteString {
                let values = ["Text": text!, "Date": strDate]  as [String : Any]
                let value = [autoID: imageUrl]  as [String : Any]
                childRef.updateChildValues(values)
                postRef.updateChildValues(value)
                  }
                }
              })
            }
          }
           dismiss(animated: true, completion: nil)
        }
             else if(tweetLength>0)
             {
                let values = ["Text": text!, "Date": strDate]  as [String : Any]

             childRef.updateChildValues(values)

             dismiss(animated: true, completion: nil)

             }

             else if(imagesNumber>0)
             {

            for image in imagesArray {

                let postRef = childRef.child("tweetImageUrl")
                let autoID = postRef.childByAutoId().key
                let childStorageRef = storageRef.child("Images").child(uid!).child(autoID)
                let tweetImage = image

                if let uploadData = UIImagePNGRepresentation(tweetImage) {

                 childStorageRef.putData(uploadData, metadata: nil, completion: { (metadata, error) in
                    if error != nil {
                        print("error")
                    } else {

                if let imageUrl = metadata?.downloadURL()?.absoluteString {
                let values = ["Date": strDate]  as [String : Any]
                childRef.updateChildValues(values)
                postRef.child(autoID).setValue(imageUrl)
                    }
                 }
              })
            }
          }
            dismiss(animated: true, completion: nil)
      }  else {
            alertTheUser(title: "error", message: "enter something.")
        }

    }//func