Metrics

The Metrics Plugin is used to gather timing information about Player’s execution of a flow. There are also platform specific integrations to include render and update times.

The diagram below illistrates some of the timing information gathered:

Usage

Core

Add the plugin to Player:

import { Player } from "@player-ui/player";
import { MetricsPlugin } from "@player-ui/metrics-plugin";

const player = new Player({
  plugins: [
    new MetricsPlugin({
      onUpdate: (metrics) => {
        // Handle the update
      },
    }),
  ],
});

The onUpdate callback will be invoked for any update to the metrics. There are also callbacks for finer-grained events (onRenderEnd, onInteractive, etc), as well as a hooks based API for even more control.

Using a custom timer

By default, all time is measured in ms using performance.now() with a fallback to the less-accurate Date.now(). If you wish to supply your own timer, simply use the getTime option to set the function to use.

Measuring Render Time

For extensions of this plugin that wish to track the render (and update) times of nodes, add the trackRenderTime flag to options. You must then call metrics.renderEnd() to denote when content is painted on the screen. This is automatically handled for the platform specific versions of this plugin.

React

The react version of the Metrics Plugin adds support for render and update times to events. The API mirrors that of the core version:

import { ReactPlayer } from "@player-ui/react";
import { MetricsPlugin } from "@player-ui/metrics-plugin-react";

const player = new ReactPlayer({
  plugins: [
    new MetricsPlugin({
      onUpdate: (metrics) => {
        // Handle the update
      },
    }),
  ],
});

Android

The JVM Metrics plugin can track render time for views in a flow.

In build.gradle

implementation "com.intuit.playerui.plugins:metrics:$PLAYER_VERSION"

In Player constructor

import com.intuit.playerui.plugins.expression.ExpressionPlugin

val metricsPlugin = MetricsPlugin { timing, renderMetrics, flowMetrics ->
  ...
}
AndroidPlayer(metricsPlugin)

iOS

The ios version of the Metrics Plugin will track initial render time for each view in a flow. Due to current SwiftUI limitations, update time can’t be tracked yet. It can be used in conjunction with a core plugin that utilizes the events, through findPlugin, or standalone.

CocoaPods

Add the subspec to your Podfile

pod 'PlayerUI/MetricsPlugin'

Swift Usage

var body: some View {
  SwiftUIPlayer(
    flow: flow,
    plugins: [
      // Tracking render time can be controlled with a parameter
      MetricsPlugin(trackRenderTime: true) { timing, nodeMetrics, flowMetrics in
        // Handle metrics payload
        log(timing.duration ?? -1)
      }
    ],
    result: $resultBinding
  )
}

Beaconing

Core

The Metrics Plugin also includes a plugin for the Beacon Plugin that adds render time to the hook context for viewed beacons send for views. This plugin is automatically registered to the Beacon Plugin if the trackRenderTime option is enabled.

In order to actually include the render-time in a beacon, you must create a BeaconPluginPlugin that maps the renderTime from the hook’s context to the actual beacon object. It can be accessed through the MetricsViewBeaconPluginContextSymbol key:

import { MetricsViewBeaconPluginContextSymbol } from '@player-ui/metrics-plugin';
import { BeaconPluginPlugin } from '@player-ui/beacon-plugin';

class MyBeaconPluginPlugin implements BeaconPluginPlugin {
  apply(beaconPlugin: BeaconPlugin) {
    beaconPlugin.hooks.buildBeacon.tap(
      { name: 'my-beacon-plugin', context: true } as Tap,
      async (context, beacon) => {
        const { renderTime } =
          (await (context as any)[MetricsViewBeaconPluginContextSymbol]) || {};

        return {
          ...beacon,
          ...(renderTime && { renderTime }),
        };
      }
    );
  }

See the Beacon Plugin for more info.