1. GetAllCategorysList

func (s *GoodsServer) GetAllCategorysList(context.Context, *emptypb.Empty) (*proto.CategoryListResponse, error){
    /*
    [
        {
            "id":xxx,
            "name":"",
            "level":1,
            "is_tab":false,
            "parent":13xxx,
            "sub_category":[
                "id":xxx,
                "name":"",
                "level":1,
                "is_tab":false,
                "sub_category":[]
            ]
        }
    ]
     */
    var categorys []model.Category
    global.DB.Where(&model.Category{Level: 1}).Preload("SubCategory.SubCategory").Find(&categorys)
    b, _ := json.Marshal(&categorys)
    return &proto.CategoryListResponse{JsonData: string(b)}, nil
}

2. GetSubCategory

func (s *GoodsServer) GetSubCategory(ctx context.Context, req *proto.CategoryListRequest) (*proto.SubCategoryListResponse, error) {
    categoryListResponse := proto.SubCategoryListResponse{}
    var category model.Category
    if result := global.DB.First(&category, req.Id); result.RowsAffected == 0{
        return nil, status.Errorf(codes.NotFound, "商品分类不存在")
    }
    categoryListResponse.Info = &proto.CategoryInfoResponse{
        Id:       category.ID,
        Name: category.Name,
        Level: category.Level,
        IsTab: category.IsTab,
        ParentCategory: category.ParentCategoryID,
    }
    var subCategorys []model.Category
    var subCategoryResponse []*proto.CategoryInfoResponse
    //preloads := "SubCategory"
    //if category.Level == 1 {
    //    preloads = "SubCategory.SubCategory"
    //}
    global.DB.Where(&model.Category{ParentCategoryID: req.Id}).Find(&subCategorys)
    for _, subCategory := range subCategorys {
        subCategoryResponse = append(subCategoryResponse, &proto.CategoryInfoResponse{
            Id: subCategory.ID,
            Name: subCategory.Name,
            Level: subCategory.Level,
            IsTab: subCategory.IsTab,
            ParentCategory: subCategory.ParentCategoryID,
        })
    }
    categoryListResponse.SubCategorys = subCategoryResponse
    return &categoryListResponse, nil
}

3. CreateCategory

func (s *GoodsServer) CreateCategory(ctx context.Context, req *proto.CategoryInfoRequest) (*proto.CategoryInfoResponse, error) {
    category := model.Category{}
    category.Name = req.Name
    category.Level = req.Level
    if req.Level != 1 {
        category.ParentCategoryID = req.ParentCategory
    }
    category.IsTab = req.IsTab
    global.DB.Save(&category)
    return &proto.CategoryInfoResponse{Id:int32(category.ID)}, nil
}

4. DeleteCategory

func (s *GoodsServer) DeleteCategory(ctx context.Context, req *proto.DeleteCategoryRequest) (*emptypb.Empty, error) {
    if result := global.DB.Delete(&model.Category{}, req.Id); result.RowsAffected == 0 {
        return nil, status.Errorf(codes.NotFound, "商品分类不存在")
    }
    return &emptypb.Empty{}, nil
}

5. UpdateCategory

func (s *GoodsServer) UpdateCategory(ctx context.Context, req *proto.CategoryInfoRequest) (*emptypb.Empty, error) {
    var category model.Category
    if result := global.DB.First(&category, req.Id); result.RowsAffected == 0 {
        return nil, status.Errorf(codes.NotFound, "商品分类不存在")
    }
    if req.Name != "" {
        category.Name = req.Name
    }
    if req.ParentCategory != 0 {
        category.ParentCategoryID = req.ParentCategory
    }
    if req.Level != 0 {
        category.Level = req.Level
    }
    if req.IsTab {
        category.IsTab = req.IsTab
    }
    global.DB.Save(&category)
    return &emptypb.Empty{}, nil
}