nats.go/example_test.go

package nats_test

import (
	"fmt"
	"time"
	"github.com/apcera/nats"
)

// Show different ways to create a Conn
func ExampleConnect() {

	nats.Connect(nats.DefaultURL)
	nats.Connect("nats://derek:secretpassword@nats.apcera.com:421")

	opts := nats.Options{
		AllowReconnect : true,
		MaxReconnect   : 10,
		ReconnectWait  : 5 * time.Second,
		Timeout        : 1 * time.Second,
	}

	nc, _ := opts.Connect()
	nc.Close()
}

// This Example shows an asynchronous subscriber.
func ExampleConn_Subscribe() {
	nc, _ := nats.Connect(nats.DefaultURL)
	defer nc.Close()

	nc.Subscribe("foo", func(m *nats.Msg) {
		fmt.Printf("Received a message: %s\n", string(m.Data))
	})
}

// This Example shows a synchronous subscriber.
func ExampleConn_SubscribeSync() {
	nc, _ := nats.Connect(nats.DefaultURL)
	defer nc.Close()

	sub, _ := nc.SubscribeSync("foo")
	m, err := sub.NextMsg(1*time.Second)
	if err == nil {
		fmt.Printf("Received a message: %s\n", string(m.Data))
	} else {
		fmt.Println("NextMsg timed out.")
	}
}

func ExampleSubscription_NextMsg() {
	nc, _ := nats.Connect(nats.DefaultURL)
	defer nc.Close()

	sub, _ := nc.SubscribeSync("foo")
	m, err := sub.NextMsg(1*time.Second)
	if err == nil {
		fmt.Printf("Received a message: %s\n", string(m.Data))
	} else {
		fmt.Println("NextMsg timed out.")
	}
}

func ExampleSubscription_Unsubscribe() {
	nc, _ := nats.Connect(nats.DefaultURL)
	defer nc.Close()

	sub, _ := nc.SubscribeSync("foo")
	// ...
	sub.Unsubscribe()
}

func ExampleConn_Publish() {
	nc, _ := nats.Connect(nats.DefaultURL)
	defer nc.Close()

	nc.Publish("foo", []byte("Hello World!"))
}

func ExampleConn_PublishMsg() {
	nc, _ := nats.Connect(nats.DefaultURL)
	defer nc.Close()

	msg := &nats.Msg{Subject:"foo", Reply:"bar", Data:[]byte("Hello World!")}
	nc.PublishMsg(msg)
}

func ExampleConn_Flush() {
	nc, _ := nats.Connect(nats.DefaultURL)
	defer nc.Close()

	msg := &nats.Msg{Subject:"foo", Reply:"bar", Data:[]byte("Hello World!")}
	for i := 0 ; i < 1000 ; i++ {
		nc.PublishMsg(msg)
	}
	err := nc.flush()
	if err == nil {
		// Everything has been processed by the server for nc *Conn.
	}
}

func ExampleConn_FlushTimeout() {
	nc, _ := nats.Connect(nats.DefaultURL)
	defer nc.Close()

	msg := &nats.Msg{Subject:"foo", Reply:"bar", Data:[]byte("Hello World!")}
	for i := 0 ; i < 1000 ; i++ {
		nc.PublishMsg(msg)
	}
	// Only wait up to 1 second for Flush
	err := nc.flushTimeout(1*time.Second)
	if err == nil {
		// Everything has been processed by the server for nc *Conn.
	}
}

func ExampleConn_Request() {
	nc, _ := nats.Connect(nats.DefaultURL)
	defer nc.Close()

	nc.Subscribe("foo", func(m *nats.Msg) {
		nc.Publish(m.Reply, []byte("I will help you"))
	})
	nc.Request("foo", []byte("help"), 50*time.Millisecond)
}

func ExampleConn_QueueSubscribe() {
	nc, _ := nats.Connect(nats.DefaultURL)
	defer nc.Close()

	received := 0

	nc.QueueSubscribe("foo", "worker_group", func(_ *nats.Msg) {
		received += 1
	})
}

func ExampleSubscription_AutoUnsubscribe() {
	nc, _ := nats.Connect(nats.DefaultURL)
	defer nc.Close()

	received, wanted, total := 0, 10, 100

	sub, _ := nc.Subscribe("foo",  func(_ *nats.Msg) {
		received += 1
	})
	sub.AutoUnsubscribe(wanted)

	for i := 0; i < total; i++ {
		nc.Publish("foo", []byte("Hello"))
	}
	nc.Flush()

	fmt.Printf("Received = %d", received)
	// Output:
	// Received = 10
}

func ExampleConn_Close() {
	nc, _ := nats.Connect(nats.DefaultURL)
	nc.Close()
}