Go RPC Tutorial

GoRPCTutorial2.go

package main

import (
	"log"
)

// Make a new ToDo type that is a typed collection of fields
// (Title and Status), both of which are of type string
type ToDo struct {
	Title, Status string
}

type EditToDo struct {
	Title, NewTitle, NewStatus string
}

type Task int

// Declare variable 'todoSlice' that is a slice made up of
// type ToDo items
var todoSlice []ToDo

// GetToDo takes a string type and returns a ToDo
func (t *Task) GetToDo(title string, reply *ToDo) error {
	var found ToDo
	// Range statement that iterates over todoArray
	// 'v' is the value of the current iterateee
	for _, v := range todoSlice {
		if v.Title == title {
			found = v
		}
	}
	// found will either be the found ToDo or a zerod ToDo
	*reply = found
	return nil
}

// MakeToDo takes a ToDo type and appends to the todoArray
func (t *Task) MakeToDo(todo ToDo, reply *ToDo) error {
	todoSlice = append(todoSlice, todo)
	*reply = todo
	return nil
}

// EditToDo takes a string type and a ToDo type and edits an item in the todoArray
func (t *Task) EditToDo(todo EditToDo, reply *ToDo) error {
	var edited ToDo
	// 'i' is the index in the array and 'v' the value
	for i, v := range todoSlice {
		if v.Title == todo.Title {
			todoSlice[i] = ToDo{todo.NewTitle, todo.NewStatus}
			edited = ToDo{todo.NewTitle, todo.NewStatus}
		}
	}
	// edited will be the edited ToDo or a zeroed ToDo
	*reply = edited
	return nil
}

// DeleteToDo takes a ToDo type and deletes it from todoArray
func (t *Task) DeleteToDo(todo ToDo, reply *ToDo) error {
	var deleted ToDo
	for i, v := range todoSlice {
		if v.Title == todo.Title && v.Status == todo.Status {
			// Delete ToDo by appending the items before it and those
			// after to the todoArray variable
			todoSlice = append(todoSlice[:i], todoSlice[i+1:]...)
			deleted = todo
			break
		}
	}
	*reply = deleted
	return nil
}

func main() {
	task := new(Task)
	var err error
	var reply ToDo

	log.Println("1. todo Slice: ", todoSlice)

	finishApp := ToDo{"Finish App", "Started"}
	makeDinner := ToDo{"Make Dinner", "Not Started"}
	walkDog := ToDo{"Walk the dog", "Not Started"}

	task.MakeToDo(finishApp, &reply)
	task.MakeToDo(makeDinner, &reply)
	task.MakeToDo(walkDog, &reply)

	log.Println("2. todo Slice: ", todoSlice)

	task.DeleteToDo(makeDinner, &reply)

	log.Println("3. todo Slice: ", todoSlice)

	task.MakeToDo(makeDinner, &reply)

	log.Println("4. todo Slice: ", todoSlice)

	task.GetToDo("Finish App", &reply)
	log.Println("5.", reply)

	task.GetToDo("Finish Application", &reply)
	log.Println("6.", &reply)

	err = task.EditToDo(EditToDo{"Finish App", "Finish App", "Completed"}, &reply)
	if err != nil {
		log.Fatal("Problem editing ToDo: ", err)
	}

	log.Println("7. todo Slice: ", todoSlice)
}