Category data now includes their subcategories. Categories can now be requested by ID in a prettier way.

main.go

@@ -1,18 +1,18 @@
 package main
 
 import (
-	"database/sql"
 	"encoding/json"
 	"fmt"
 	"io/ioutil"
 	"net/http"
 	"strconv"
+	"strings"
 	"time"
 )
 
 //Go Best practices: https://github.com/golovers/effective-go
 type Item struct {
-	Id                int32       `json:"id"`
+	ID                int32       `json:"id"`
 	Name              int32       `json:"name"`
 	ValueCents        int32       `json:"valueCents"`
 	PurchaseCostCents int32       `json:"purchasedCostCents"`
@@ -27,8 +27,11 @@ type Item struct {
 
 func main() {
 	http.HandleFunc("/categories", categories)
-	http.HandleFunc("/category", category)
-	err := http.ListenAndServe(":8080", nil)
+	//Note: seems adding a trailing slash allows routing URLs like /category/ID#
+	//No need for query parameters.
+	http.HandleFunc("/category/", category)
+
+	err := http.ListenAndServe(":8088", nil)
 
 	if err != nil {
 		panic(err)
@@ -39,7 +42,7 @@ func main() {
 func categories(w http.ResponseWriter, r *http.Request) {
 	switch r.Method {
 	case "GET":
-		getCategories(w, r)
+		getCategoriesHandler(w, r)
 	default:
 		w.WriteHeader(http.StatusMethodNotAllowed)
 		w.Write([]byte("Method not allowed"))
@@ -49,19 +52,19 @@ func categories(w http.ResponseWriter, r *http.Request) {
 func category(w http.ResponseWriter, r *http.Request) {
 	switch r.Method {
 	case "GET":
-		getCategory(w, r)
+		getCategoryHandler(w, r)
 	case "POST":
-		insertCategory(w, r)
+		insertCategoryHandler(w, r)
 	case "DELETE":
-		deleteCategory(w, r)
+		deleteCategoryHandler(w, r)
 	default:
 		w.WriteHeader(http.StatusMethodNotAllowed)
 		w.Write([]byte("Method not allowed"))
 	}
 }
 
-func getCategory(w http.ResponseWriter, r *http.Request) {
-	id := r.URL.Query().Get("id")
+func getCategoryHandler(w http.ResponseWriter, r *http.Request) {
+	id := strings.TrimPrefix(r.URL.Path, "/category/")
 
 	value, err := strconv.ParseInt(id, 0, 64)
 
@@ -71,19 +74,11 @@ func getCategory(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	db := getSQLConnection()
+	category, ok := getCategoryByID(value)
 
-	defer db.Close()
-
-	var category Category
-
-	if err := db.QueryRow("SELECT * FROM category WHERE category_id = $1;", value).Scan(&category.Id, &category.Name); err != nil {
-		if err == sql.ErrNoRows {
-			w.Write([]byte("No rows found"))
-			return
-		}
-
-		w.Write([]byte(err.Error()))
+	if !ok {
+		w.WriteHeader(http.StatusInternalServerError)
+		w.Write([]byte("Failed to get category."))
 		return
 	}
 
@@ -99,8 +94,8 @@ func getCategory(w http.ResponseWriter, r *http.Request) {
 	w.Write(jsonBytes)
 }
 
-func deleteCategory(w http.ResponseWriter, r *http.Request) {
-	id := r.URL.Query().Get("id")
+func deleteCategoryHandler(w http.ResponseWriter, r *http.Request) {
+	id := strings.TrimPrefix(r.URL.Path, "/category/")
 
 	value, err := strconv.ParseInt(id, 0, 64)
 
@@ -110,24 +105,23 @@ func deleteCategory(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	db := getSQLConnection()
-
-	defer db.Close()
-
-	_, err = db.Exec("DELETE FROM category WHERE category_id = $1;", value)
-
-	if err != nil {
+	if !deleteCategory(value) {
 		w.WriteHeader(http.StatusBadRequest)
-		w.Write([]byte(err.Error()))
+		w.Write([]byte(fmt.Sprintf("Failed to delete %d", value)))
 		return
 	}
 
 	w.WriteHeader(http.StatusOK)
-	w.Write([]byte(fmt.Sprintf("Deleted category '%d'.", value)))
 }
 
-func getCategories(w http.ResponseWriter, r *http.Request) {
-	categories := getAllCategories()
+func getCategoriesHandler(w http.ResponseWriter, r *http.Request) {
+	categories, ok := getAllCategories()
+
+	if !ok {
+		w.WriteHeader(http.StatusInternalServerError)
+		w.Write([]byte("Failed to fetch a list of categories."))
+		return
+	}
 
 	jsonBytes, err := json.Marshal(categories)
 
@@ -141,12 +135,12 @@ func getCategories(w http.ResponseWriter, r *http.Request) {
 	w.Write(jsonBytes)
 }
 
-func insertCategory(w http.ResponseWriter, r *http.Request) {
+func insertCategoryHandler(w http.ResponseWriter, r *http.Request) {
 	ct := r.Header.Get("content-type")
 
 	if ct != "application/json" {
 		w.WriteHeader(http.StatusUnsupportedMediaType)
-		w.Write([]byte(fmt.Sprintf("Unsupported media type '%s'", ct)))
+		w.Write([]byte(fmt.Sprintf("Unsupported media type '%s', expected application/json", ct)))
 		return
 	}
 
@@ -170,17 +164,11 @@ func insertCategory(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	db := getSQLConnection()
+	id, ok := insertNewCategory(category.Name)
 
-	defer db.Close()
-
-	id := 0
-
-	err = db.QueryRow("INSERT INTO category (category_name) VALUES ($1) RETURNING category_id;", category.Name).Scan(&id)
-
-	if err != nil {
+	if !ok {
 		w.WriteHeader(http.StatusInternalServerError)
-		w.Write([]byte(err.Error()))
+		w.Write([]byte("Failed to create the new category."))
 		return
 	}