Simple RTDB validation example

example_validate_rules.js

{
  "aListOfRecords": {
     // when querying our list, must get less than 50 at a time and be authenticated
     ".read": "auth != null && (query.limitToFirst <= 50 || query.limitToLast <= 50)",
    
     "$aRecordId": {
        // When fetching a single record, I must be logged in
        ".read": "auth != null",
       
        // When writing a record, I must be logged in
        ".write": "auth != null",
       
        // Validate my schema
        "aNumberField": { ".validate": "newData.isNumber() && newData.val() > -1 && newData.val() < 51" },
        "aStringField": { ".validate": "newData.isString() && newData.val().length < 4" }
       
        // Disallow any fields not in my schema
        "$other": { ".validate": false }
     }
  }
}