Rules { “rules”: { “Accounts”: { “.read”: “true”, “$user_id”: { // Check if object has all required values after operation “.validate”: “newData.child(‘Username’).isString() && newData.child(‘Password’).isString() && newData.child(‘Salt’).isString() && newData.child(‘ExpirationDate’).isString()”, // Only allow username update if: // * There is a provided username AND // * There is no existing username (new account) OR // * It […]