How to Create a Custom Event Logging System in FlutterFlow

Create an event_log collection with fields: eventName (String), userId (String), sessionId (String), properties (Map, for key-value metadata), platform (String: ios, android, or web), appVersion (String), timestamp (Timestamp). Create Firestore indexes on eventName + timestamp descending for efficient querying. Add a second index on userId + timestamp descending for per-user event history. The properties map lets you attach arbitrary context to each event, such as the button name, page name, product ID, or error message.

Create a Custom Action named logEvent that takes two parameters: eventName (String, required) and properties (Map of String to dynamic, optional). Inside the action, get the current user ID from the authenticated user. Get the sessionId from App State (set on app launch). Write a document to the event_log collection with all fields. Critically, do NOT await the Firestore write — use fire-and-forget so the event logging does not add latency to the user's action flow. This means calling the create document method without await so it runs in the background.

1// Custom Action: logEvent
2import 'package:cloud_firestore/cloud_firestore.dart';
3import 'dart:io' show Platform;
4
5Future<void> logEvent(
6  String eventName,
7  String sessionId,
8  Map<String, dynamic>? properties,
9) async {
10  final userId = FirebaseAuth.instance.currentUser?.uid ?? 'anonymous';
11  // Fire-and-forget: intentionally not awaiting
12  FirebaseFirestore.instance.collection('event_log').add({
13    'eventName': eventName,
14    'userId': userId,
15    'sessionId': sessionId,
16    'properties': properties ?? {},
17    'platform': Platform.isIOS ? 'ios' : 'android',
18    'timestamp': FieldValue.serverTimestamp(),
19  });
20}

In your App State, create a sessionId variable of type String with no persistence (resets on each app launch). On your initial page's On Page Load action (or your app's entry point), generate a unique session ID using a Custom Function that returns a UUID string. Store it in App State sessionId. This ID is passed to every logEvent call so you can group all events from a single app session together. Additionally, call logEvent with eventName 'session_start' to mark the beginning of each session.

Add logEvent calls to your existing Action Flows at strategic points. On each page's On Page Load action, call logEvent with eventName 'page_view' and properties containing the page name. On important button taps (sign up, purchase, add to cart), call logEvent with a descriptive event name and relevant properties like product ID or amount. On error states, call logEvent with eventName 'error_occurred' and properties containing the error message and context. Aim for 5 to 10 key events that cover the most important user journey steps.

Create an AdminEventsPage accessible only to admin users. Add a DropDown at the top to filter by eventName (populated from distinct event names). Add a DatePicker range for filtering by time period. Below, display a summary Row with total events count, unique users count, and unique sessions count for the selected filters. Add a ListView showing recent events with eventName, userId, properties, and timestamp. For trend visualization, add a Custom Widget using fl_chart that shows a BarChart of daily event counts over the past 7 days. Use a Custom Function to aggregate the event data by day.

Create a scheduled Cloud Function that runs daily and anonymizes event logs older than 90 days by replacing the userId with 'anonymized'. Add a Cloud Function for data export that queries events for a date range and writes them as a CSV file to Firebase Storage, returning the download URL. On the admin dashboard, add an Export CSV button that calls this function and opens the download URL. In the app settings, add a toggle for users to opt out of analytics. Check this preference in the logEvent Custom Action and skip writing if the user has opted out.