如何使用.on('child_added') 返回所有孩子？

Question

In firebase, I want to use.on('child_added') to return all children rather than returning just one children. I want all children after every child_added, so.once('value') is not an option. How to achieve this?

For eg. In my database I have, [book1, book2, book3] as children. When I add a new child book4, the.on('child_added') returns only {book4}. I want it to return [book1,book2,book3,book4] Help me with this.

Answer 1

You can use on('value') to receive updates to any child under a node. Any time anything changes under that node, it will receive a snapshot of all nested children.