Function Example_jsonDecoder

runtimevar/example_test.go:31–65

()

)

func Example_jsonDecoder() {
	// PRAGMA: This example is used on gocloud.dev; PRAGMA comments adjust how it is shown and can be ignored.
	// PRAGMA: On gocloud.dev, hide lines until the next blank line.
	ctx := context.Background()

	// Config is the sample config struct we're going to parse our JSON into.
	type Config struct {
		Host string
		Port int
	}

	// A sample JSON config that will decode into Config.
	const jsonConfig = `{"Host": "gocloud.dev", "Port": 8080}`

	// Construct a Decoder that decodes raw bytes into our config.
	decoder := runtimevar.NewDecoder(Config{}, runtimevar.JSONDecode)

	// Next, a construct a *Variable using a constructor or URL opener.
	// This example uses constantvar.
	// If you're using a URL opener, you can't decode JSON into a struct, but
	// you can use the query parameter "decoder=jsonmap" to decode into a map.
	v := constantvar.NewBytes([]byte(jsonConfig), decoder)
	defer v.Close()
	// snapshot.Value will be of type Config.

	// PRAGMA: On gocloud.dev, hide the rest of the function.
	snapshot, err := v.Latest(ctx)
	if err != nil {
		log.Fatalf("Error in retrieving variable: %v", err)
	}
	fmt.Printf("Config: %+v\n", snapshot.Value.(Config))

	// Output:
	// Config: {Host:gocloud.dev Port:8080}
}

func Example_stringDecoder() {
	// Construct a *Variable using a constructor from one of the