Limit number of child nodes
This template shows how to keep the number of child nodes in a Firebase database below a given number. This can be used to limit the number of lines of a chat history or logs.
See file functions/index.js for the code.
The dependencies are listed in functions/package.json.
Sample Database Structure
As an example we'll be using a simple chat database structure:
/functions-project-12345 /chat /key-123456 user: "Mat", text: "Hey Bob!" /key-123457 user: "Bob", text: "Hey Mat! What's Up?"
Every time a new chat message is added the Function runs. It counts the number of chat messages and removes the old ones if there are too many.