A simple tutorial of how to use zegl/goriak with SetMap, GetMap, and Sets

task.go

package main

import (
	"gopkg.in/zegl/goriak.v3"

	"errors"
	"fmt"
)

// Initialize connection to Riak
func init() {
	client, err := goriak.Connect(goriak.ConnectOpts{
		Address: "127.0.0.1",
	})

	if err != nil {
		panic(err)
	}

	r = client
}

// Our connection to Riak and the goriak library
var r *goriak.Session

func main() {
	// Create a new task
	// Initialize it with a Title and the Tag "shopping"
	task := NewTask("task-1", "Buy Apples", []string{"shopping"})

	// Save the item to Riak
	task.Save()

	// Retreive the same task
	get, err := GetTask("task-1")

	if err != nil {
		panic(err)
	}

	// Print what the Task contains
	fmt.Printf("Task: %s\n", get.Title)
	fmt.Printf("Tags: %+v\n", get.Tags.Strings())

	// Add one more tag and save the change to Riak
	err = get.Tags.AddString("groceries").Exec(r)

	if err != nil {
		panic(err)
	}

	fmt.Println("Retreive again from Riak:")

	// Retreive the same task
	get, err = GetTask("task-1")

	if err != nil {
		panic(err)
	}

	// Print what the Task contains
	fmt.Printf("Task: %s\n", get.Title)
	fmt.Printf("Tags: %+v\n", get.Tags.Strings())
}

type Task struct {
	Handle string
	Title  string
	Tags   *goriak.Set
}

// NewTask creates a new Task item
func NewTask(handle, title string, tags []string) *Task {
	t := &Task{
		Handle: handle,
		Title:  title,
		Tags:   goriak.NewSet(), // It is important to initialize our Set if we want to use it
	}

	for _, tag := range tags {
		t.Tags.AddString(tag)
	}

	return t
}

// Save uses SetMap from Riak to save everything in our Task object directly to RIak
func (t *Task) Save() {
	_, err := goriak.Bucket("tasks", "maps").Set(t).Key(t.Handle).Run(r)
	if err != nil {
		panic(err)
	}
}

// GetTask retreices a Task by handle
func GetTask(handle string) (*Task, error) {
	t := Task{}

	_, err := goriak.Bucket("tasks", "maps").Get(handle, &t).Run(r)
	if err != nil {
		return nil, errors.New("Could not get task from Riak: " + err.Error())
	}

	return &t, nil
}