Go - Topic.Publish()

Publish an event (push based message) to a topic.

import (
  "context"
  "fmt"

  "github.com/nitrictech/go-sdk/api/events"
  "github.com/nitrictech/go-sdk/nitric"
)

func main() {
  updates, err := nitric.NewTopic("updates").With(nitric.TopicPublishing)
  if err != nil {
    fmt.Println(err)

    return
  }

  updates.Publish(context.TODO(), &events.Event{
    Payload: map[string]interface{}{
      "something": "amazing happened",
    },
  })

  nitric.Run()
}

Parameters

Name
ctx
Required
Required
Type
context
Description
The context of the call, used for tracing.
Name
event
Required
Required
Type
Event
Description
The event to publish to the topic.
Name
ID
Optional
Optional
Type
string
Description
Unique ID to apply to the event.
Name
Payload
Required
Required
Type
map[string]interface{}
Description
Payload to send with the event.
Name
PayloadType
Optional
Optional
Type
string
Description
A hint to the type of payload supplied.
Name
opts
Optional
Optional
Type
PublishOption
Description
Optional function to send a message with a delay.

Examples

Publish a message

Publishing messages to a topic will push a copy of the message to each of the topic's subscribers. By default, delivery occurs without a delay.

import (
  "context"
  "fmt"

  "github.com/nitrictech/go-sdk/api/events"
  "github.com/nitrictech/go-sdk/nitric"
)

func main() {
  updates, err := nitric.NewTopic("updates").With(nitric.TopicPublishing)
  if err != nil {
    fmt.Println(err)

    return
  }

  err := updates.Publish(context.TODO(), &events.Event{
    Payload: map[string]interface{}{
      "something": "amazing happened",
    },
  })
  nitric.Run()
}

Delaying message delivery

You can delay the delivery of messages sent to a topic. The current maximum delay is 7 days (604800 seconds).

import (
  "context"
  "fmt"
  "time"

  "github.com/nitrictech/go-sdk/api/events"
  "github.com/nitrictech/go-sdk/nitric"
)

func main() {
  updates, err := nitric.NewTopic("updates").With(nitric.TopicPublishing)
  if err != nil {
    fmt.Println(err)

    return
  }

  updates.Publish(context.TODO(), &events.Event{
    Payload: map[string]interface{}{
      "something": "amazing happened",
    },
  }, events.WithDelay(time.Hour))

  nitric.Run()
}

Notes

If an id is not supplied with an event a UUID(v4) will be generated for you.
A function may subscribe to OR publish to a topic but not both.