GettingStarted.md

Getting Started With Telemetry

A quick guide to using Telemetry.

Quick Start Guide

First, Create a Telemeter

A Telemeter is used to record events anywhere in your code. Creating one is simple:

let telemeter = StandardTelemeter()

Next, Configure Relays

A telemeter will need to send data somewhere to be useful, this is where Relays come in. The ConsoleRelay will output events with the specified Significance to the console. Let's add one that will output all metrons.

telemeter.add(relay: ConsoleRelay(allowedSignificances: .all)

Define an Event

You'll define events that you record to a telemeter. An event you define must conform to the Metron protocol.

enum AddToCartEvent: Metron {
    case itemAdded(Product)
    case addFailed(Error)

    var message: String {
        switch self {
        case .itemAdded(let product):
            return "Added item to cart: \(product.name)"

        case .addFailed:
            return "Failed to add item to cart"
        }
    }

    var facets: [Facet] {
        switch self {
        case .itemAdded: return [.informational]
        case .addFailed(let error): return [Failure(error), .error]
        }
    }
}

Finally, Record the event

Recording an event is easy, just call .record on a Telemeter instance:

telemeter.record(AddToCartEvent.itemAdded(product))