Recap - REST API Models

Part of the Object Oriented Programming section of Coddy's GO journey — lesson 78 of 107.

Challenge

Easy

Let's build a REST API model system for a blog platform! You'll create well-structured types that serialize to JSON and provide readable string representations—exactly what you'd need when building real API responses.

You'll organize your code across two files:

models.go: Define your API data models with proper JSON tags and string representations.
Create an Author struct with ID (int), Name (string), and Email (string) fields. Map these to JSON keys "id", "name", and "email". Implement String() to return the format [Name] <[Email]>.

Create a Post struct with ID (int), Title (string), Content (string), Author (nested Author struct), and Published (bool). Map these to "id", "title", "content", "author", and "published". The Content field should use omitempty so empty content doesn't appear in JSON. Implement String() to return "[Title]" by [Author's String representation].

Create an APIResponse struct with Success (bool), Message (string), and Data (Post). Map to "success", "message", and "data". The Message field should use omitempty.
main.go: Build API responses and demonstrate both JSON output and string representations.
Read an operation type (json or display), then read post details: post ID, title, content, author ID, author name, author email, and published status (true or false).

For json: Create an APIResponse with Success: true and the Post as data (leave Message empty). Convert to JSON and print it.

For display: Create the Post and print it using its String method, then print the Author separately on a new line.

The following inputs will be provided:

Line 1: Operation type (json or display)
Line 2: Post ID
Line 3: Title
Line 4: Content (may be empty)
Line 5: Author ID
Line 6: Author name
Line 7: Author email
Line 8: Published status (true or false)

For example, given:

json
1
Getting Started with Go
Learn the basics of Go programming
101
Jane Smith
jane@example.com
true

Your output should be:

{"success":true,"data":{"id":1,"title":"Getting Started with Go","content":"Learn the basics of Go programming","author":{"id":101,"name":"Jane Smith","email":"jane@example.com"},"published":true}}

And given:

json
2
Draft Post

102
John Doe
john@example.com
false

Your output should be:

{"success":true,"data":{"id":2,"title":"Draft Post","author":{"id":102,"name":"John Doe","email":"john@example.com"},"published":false}}

Notice how the empty content field is omitted from the JSON output.

And given:

display
3
Advanced Interfaces
Deep dive into Go interfaces
103
Alice Chen
alice@example.com
true

Your output should be:

"Advanced Interfaces" by Alice Chen <alice@example.com>
Alice Chen <alice@example.com>

Try it yourself

package main

import (
	"bufio"
	"encoding/json"
	"fmt"
	"os"
	"strconv"
	"strings"
)

func main() {
	reader := bufio.NewReader(os.Stdin)

	// Read operation type
	operation, _ := reader.ReadString('\n')
	operation = strings.TrimSpace(operation)

	// Read post ID
	postIDStr, _ := reader.ReadString('\n')
	postID, _ := strconv.Atoi(strings.TrimSpace(postIDStr))

	// Read title
	title, _ := reader.ReadString('\n')
	title = strings.TrimSpace(title)

	// Read content
	content, _ := reader.ReadString('\n')
	content = strings.TrimSpace(content)

	// Read author ID
	authorIDStr, _ := reader.ReadString('\n')
	authorID, _ := strconv.Atoi(strings.TrimSpace(authorIDStr))

	// Read author name
	authorName, _ := reader.ReadString('\n')
	authorName = strings.TrimSpace(authorName)

	// Read author email
	authorEmail, _ := reader.ReadString('\n')
	authorEmail = strings.TrimSpace(authorEmail)

	// Read published status
	publishedStr, _ := reader.ReadString('\n')
	published := strings.TrimSpace(publishedStr) == "true"

	// TODO: Create an Author struct with the read values

	// TODO: Create a Post struct with the read values and the Author

	// TODO: Handle the operation type
	// If operation is "json":
	//   - Create an APIResponse with Success: true and the Post as Data
	//   - Convert to JSON using json.Marshal
	//   - Print the JSON string
	// If operation is "display":
	//   - Print the Post using its String method
	//   - Print the Author on a new line

	// Placeholder to use variables (remove when implementing)
	_ = postID
	_ = title
	_ = content
	_ = authorID
	_ = authorName
	_ = authorEmail
	_ = published
	_ = operation
	_ = json.Marshal
	fmt.Println("TODO: Implement the solution")
}