ios – 在Swift中向Firebase数组添加项目而不首先观察数组

REF_USER.child(UID).observeSingleEventOfType(.Value,withBlock: { snapshot in
   if !snapshot.exists() {return}
   if let Dict = snapshot.value as? Dictionary<String,AnyObject>,let posts = Dict["posts" as? [String] {
      posts.append(newPost)
      REF_USER.child(UID + "/posts").SETVALue(posts)
   }
}

REF_USER.child(UID + "/posts").addToArray(newPost)

通常很好的做法是避免使用Firebase中的数组,因为它们非常难以处理;单个元素无法直接访问,无法更新 – 必须重新编写.

不确定为什么要通过问题中列出的步骤添加新帖子,但这是另一种解决方案：

thisPostRef = postsRef.childByAutoId //create a new post node
thisPostRef.SETVALue("here's a new post") //store the post in it

编辑：

这将产生这样的结构

posts
  post_id_0: "here's a new post"
  post_id_1: "another post"
  post_id_2: "cool post"

这种结构避免了数组的缺陷.

另一个编辑. OP询问如何将其写入users / UID / posts节点

usersRef = rootRef.childByAppendingPath("users")
thisUserRef = usersRef.childByAppendingPath(the users uid)
thisUserPostRef = thisUserRef.childByAutoId //create a new post node
thisUserPostRef.SETVALue("here's a new post") //store the post in it