add next/previous button to edititemhtml

repositories/shopItemRepository.go

@@ -1,6 +1,7 @@
 package repositories
 
 import (
+	"fmt"
 	"gorm.io/gorm"
 	"strconv"
 
@@ -12,6 +13,8 @@ type ShopItemRepository interface {
 	GetAll() ([]models.ShopItem, error)
 	GetAllPublic() ([]models.ShopItem, error)
 	GetById(string) (models.ShopItem, error)
+	GetNextOfId(string) (models.ShopItem, error)
+	GetPreviousOfId(string) (models.ShopItem, error)
 	GetByTagId(string) ([]models.ShopItem, error)
 	GetVariantById(string) (models.ItemVariant, error)
 	Update(models.ShopItem) (models.ShopItem, error)
@@ -68,6 +71,30 @@ func (r *GORMShopItemRepository) GetById(id string) (models.ShopItem, error) {
 	return shopItem, nil
 }
 
+func (r *GORMShopItemRepository) GetNextOfId(id string) (models.ShopItem, error) {
+	var nextItem models.ShopItem
+	if err := r.DB.Where("id > ?", id).Order("id asc").First(&nextItem).Error; err != nil {
+		if err != gorm.ErrRecordNotFound {
+			return models.ShopItem{}, err
+		} else {
+			return models.ShopItem{}, fmt.Errorf("No Item found")
+		}
+	}
+	return nextItem, nil
+}
+
+func (r *GORMShopItemRepository) GetPreviousOfId(id string) (models.ShopItem, error) {
+	var previousItem models.ShopItem
+	if err := r.DB.Where("id < ?", id).Order("id desc").First(&previousItem).Error; err != nil {
+		if err != gorm.ErrRecordNotFound {
+			return models.ShopItem{}, err
+		} else {
+			return models.ShopItem{}, fmt.Errorf("No Item found")
+		}
+	}
+	return previousItem, nil
+}
+
 func (r *GORMShopItemRepository) GetByTagId(id string) ([]models.ShopItem, error) {
 	tagId, err := strconv.Atoi(id)