A Google Analytics wrapper for command-line, web, and Flutter apps.

While regularly checking the output size (after dart2js) of your web application, I noticed a big increase. The uncompressed size of our javascript file increased by 400 kb. After compression using gzip it is still 100 kb bigger than before. This is not acceptable for us.

I investigated what this increase is causing: It is the use of the uuid package and all it's dependencies. Currently uuid is used to generate the unique client id. Using uuid in console applications is fine. Looks like the normal Google Analytics implementation is only using a simple random number as a client id.

I think it would be usefull if the generator for the client id could be set from the outside, or to force the use of a simple random number for the Html version of the library. The client id generator could be a simple callback function or a class as we already have for PostHandler and PersistentProperties.

Making use of the /batch endpoint as described here: https://developers.google.com/analytics/devguides/collection/protocol/v1/devguide#batch

By default all events sent within the same sync-block (really until returning to the event-loop ) will be batched together. By changing the batchDelay in the constructor one can set a timeout after which all batched events are sent, or avoid the batching altogether.

I am trying to use this with the new web + app analytics by google, but i never receive events. is it possible that this is not possible with this library?

Fixes https://github.com/dart-lang/usage/issues/112

Wasn't sure what you wanted me to do. But here's a start.

Also, not sure how to test this? I updated the test but it wasn't clear how to verify that it actually worked? The tests didn't fail.

I didn't find a grind task for running tests or analyzing, so I ran the tests by hand.

Thanks for taking a look!

Many methods in Analytics use optional positionals. IMO optional positional should rarely be used on public APIs:

• Callsite is less readable, especially for bools.
• Hard to add more optional arguments in the future.
• Have to pass null when you only care about the trailing optionals (which might overwrite the default value).

Change to named arguments?

https://support.google.com/analytics/answer/2709828?hl=en

We'd like to send custom dimensions for screens and events. Is there a way to do this with usage?

Thanks!

The sendTiming parameter time is of type int, but internally type string is required. Im using

      _analytics.sendTiming('LoadTime', stopwatch.elapsedMilliseconds);

but it crashes as postEncode in usage_impl.dart requires all map values to be strings, but 'utt' is an integer. Therefore time should be converted to a string first.

Interacting quickly with ui elements that trigger some tracking causes the package to stop working.

This comes from the ThrottlingBucket.removeDrop() method that always returns false after a "successful" burst of requests, which prevents any subsequent attempt to send a payload to GA. The ThrottlingBucket class doesn't recover from this burst: the number of drops remains forever negative.

The problem appeared while I was navigating rather fast in my app, but at a speed similar to a real life situation. And I am only tracking screen views at the moment, so this problem might occur more frequently when the app tracks screen views, events, exceptions, etc. and the stress on the throttling bucket increases.

I have narrowed it down to the throttling bucket by adding a break point to the else part of the _sendPayload method:

Future _sendPayload(String hitType, Map<String, dynamic> args) {
   if (!enabled) return Future.value();

   if (_bucket.removeDrop()) {
     _variableMap.forEach((key, value) {
       args[key] = value;
     });

     args['v'] = '1'; // protocol version
     args['tid'] = trackingId;
     args['cid'] = clientId;
     args['t'] = hitType;

     _sendController.add(args);

     return _recordFuture(postHandler.sendPost(_url, args));
   } else {
     return Future.value(); // <========= BREAK POINT HERE
   }
 }

The app never stops there, until the burst of interaction succeeds in messing the throttling, then any subsequent attempt to track stops there, which I think proves the number of drops stays negative.

• always_declare_return_types
• omit_local_variable_types
• prefer_collection_literals
• prefer_if_null_operators
• unawaited_futures

Bump min SDK to 2.2.0 to support Set literals.

E/flutter : [ERROR:dart_error.cc(17)] Unhandled exception:
E/flutter : No top-level method 'getFilesDir' declared.
E/flutter : 
E/flutter : NoSuchMethodError: method not found: 'getFilesDir'
E/flutter : Receiver: top-level
E/flutter : Arguments: [...]
E/flutter : #0      NoSuchMethodError._throwNew (dart:core-patch/errors_patch.dart:169)
E/flutter : #1      createAnalytics.<createAnalytics_async_body> (package:usage/src/usage_impl_flutter.dart:22)
E/flutter : #2      Future.Future.microtask.<anonymous closure> (dart:async/future.dart:144)
E/flutter : #3      _microtaskLoop (dart:async/schedule_microtask.dart:41)
E/flutter : #4      _startMicrotaskLoop (dart:async/schedule_microtask.dart:50)

https://github.com/dart-lang/usage/blob/775bffd3a0c966e4dbc4e3e2c9fd6e29c079c054/lib/src/usage_impl_flutter.dart#L22

getFilesDir was removed from flutter in https://github.com/flutter/flutter/pull/3636

We have problems with errors from HttpRequest.request. There are several reasons that temporary error can occure, I our case it seems to be a Safari problem.

For now that means that we have a unhandled exception that crashes the application. We can add manually a catchError to the returned futures from the Analytics class.

Now I wonder if we should move handling such exceptions directly into the post handler?

From the google analytics docs:

all standard Universal Analytics properties will stop processing new hits on July 1, 2023

We don't yet know whether we'll support GA4 in this package or leave that to another package. If we do support it here, it's enough of a protocol change that we likely wouldn't try for backwards compatibility in the APIs; i.e. v4 of this package and v5 would have different APIs (one that matched the needs of the older measurement protocol and one that matched the needs of GA4).

This issue tracks discussing whether this package will be upgraded to support GA4 or not.

--

Notes:

• deprecation notice: https://support.google.com/analytics/answer/11583528?hl=en
• GA4 info: https://support.google.com/analytics/answer/10089681
• GA4 protocol: https://developers.google.com/analytics/devguides/collection/protocol/ga4 and https://developers.google.com/analytics/devguides/collection/protocol/ga4/validating-events?client_type=gtag

In order to support tracking a user across devices it would very handy to set the clientId manually. Support for this could be easily added by providing a setter for clientId in usage_impl.dart.

It looks like the settings are serialized to and from a file, however it would be nice to have control over where the data is being loaded and saved to (i.e. a data store, in memory, etc.). It would be helpful to have optional callbacks in the constructor that would handle saving and loading the serialized data, if omitted then file persistence would be required.

Following the XDG Base Directory Specification makes this applications using this library better citizens on unixes.

If the previously default file (named .$applicationName in the user's HOME directory) exists, or documentDirectory is specified, the behaviour is the same as before. In other cases, $XDG_CONFIG_HOME/applicationName/analytics is used.

The code is pretty much the same as in my PR on the flutter repo and I submitted this PR to complete my mission of clearing flutter users' home directories of flutter files.