Support Firebase Performance Monitoring #370

Author: EddyVerbruggen

README.md

@@ -1,5 +1,6 @@
 # NativeScript Firebase plugin
 
+[![Build Status][build-status]][build-url]
 [![NPM version][npm-image]][npm-url]
 [![Downloads][downloads-image]][npm-url]
 [![Twitter Follow][twitter-image]][twitter-url]
@@ -24,6 +25,7 @@
 * [Crash Reporting / Crashlytics](docs/CRASHREPORTING.md)
 * [Invites and Dynamic Links](docs/INVITES_DYNAMICLINKS.md)
 * [ML Kit](docs/ML_KIT.md)
+* [Performance Monitoring](docs/PERFORMANCE_MONITORING.md)
 * [Realtime Database](docs/DATABASE.md)
 * [Remote Config](docs/REMOTECONFIG.md)
 * [Storage](docs/STORAGE.md)

docs/FUNCTIONS.md

@@ -19,11 +19,11 @@ To add this feature to your project, either:
 In both cases, remove the `/platforms` folder afterwards so the required native library will be added upon the next build. 
 
 
-## Functions
+## API
 You can use either the Web API syntax (easy for interoperability with a web version of your app), or our custom native syntax.
 Use whichever syntax you like most - the underlying implementation is the same.
 
-### httpsCallable
+### `httpsCallable`
 This example uses the Cloud Function as [implemented here](https://github.com/EddyVerbruggen/nativescript-plugin-firebase/blob/ff95c77c7b09acf66654f53c52e8ae0c8d7b1c78/demo/firebasefunctions/functions/src/index.ts#L15-L19).
 
 <details>

docs/PERFORMANCE_MONITORING.md

@@ -0,0 +1,84 @@
+<img src="https://raw.githubusercontent.com/EddyVerbruggen/nativescript-plugin-firebase/master/docs/images/features/performancemonitoring.png" height="85px" alt="Performance Monitoring"/>
+
+> Added in plugin version 7.3.0
+
+## Performance Monitoring?
+With Firebase Performance Monitoring you get insights into how your app performs from your users' point of view, with automatic and customized performance tracing.
+                                                                                          
+[Learn more here..](https://firebase.google.com/products/performance/)
+
+## Enabling Performance Monitoring
+To add this feature to your project, either:
+
+* Remove `firebase.nativescript.json` from the root of the project and run `npm i`, or
+* Edit that file and add `"performance_monitoring": true`.
+
+In both cases, remove the `/platforms` folder afterwards so the required native library will be added upon the next build. 
+
+## API
+You can use either the Web API syntax (easy for interoperability with a web version of your app), or our custom native syntax.
+Use whichever syntax you like most - the underlying implementation is the same.
+
+### `startTrace`
+You need to start and stop a trace, so remember the started trace in some property:
+
+```typescript
+import { performance as firebasePerformance } from "nativescript-plugin-firebase";
+import { FirebaseTrace } from "nativescript-plugin-firebase/performance/performance";
+
+const firebaseTrace: FirebaseTrace = firebasePerformance.startTrace("myTrace");
+```
+
+Now you can call several functions on the remembered trace object, read on below. And don't forget to use `trace.stop`.
+
+### `trace.setValue`
+
+```typescript
+if (firebaseTrace) {
+  firebaseTrace.setValue("foo", "bar");
+}
+```
+
+### `trace.getValue`
+
+```typescript
+if (firebaseTrace) {
+  firebaseTrace.getValue("foo");
+}
+```
+
+### `trace.getAttributes`
+
+```typescript
+if (firebaseTrace) {
+  const attributes = firebaseTrace.getAttributes();
+  console.log(`trace attributes: ${attributes}`);
+}
+```
+
+### `trace.removeAttribute`
+
+```typescript
+if (firebaseTrace) {
+  const attributes = firebaseTrace.removeAttribute("foo");
+}
+```
+
+### `trace.incrementMetric`
+
+```typescript
+if (firebaseTrace) {
+  const incrementBy = 1;
+  const attributes = firebaseTrace.incrementMetric("foo_metric", incrementBy);
+}
+```
+
+### `trace.stop`
+To stop the trace, call `stop` on the remembered trace object:
+
+```typescript
+if (firebaseTrace) {
+  firebaseTrace.stop();
+  firebaseTrace = undefined;
+}
+```