rest-api/handler/articles.go

package handler

import (
	"go-rest-api/database"
	"go-rest-api/model"
	"net/http"

	"github.com/go-playground/validator/v10"
	"github.com/labstack/echo/v4"
	"go.mongodb.org/mongo-driver/bson"
)

var (
	internalErr        = "Unable to operate on Article."
	articleNotFoundErr = "Article not found."
	validationErr      = "Validation Error."
)

// AttachArticleHandlersToRouter func
func AttachArticleHandlersToRouter(e *echo.Echo) {
	db := database.NewMongoDb()
	ah := NewArticlesHandler(db)

	g := e.Group("/articles")
	g.GET("", ah.getAllArticles)
	g.GET("/:id", ah.getOneArticle)
	g.POST("", ah.createArticle)
	g.PUT("/:id", ah.updateArticle)
	g.DELETE("/:id", ah.removeArticle)
}

// NewArticlesHandler return ArticlesHandler
func NewArticlesHandler(db *database.MongoDb) ArticlesHandler {
	return ArticlesHandler{
		parent: BaseHandler{
			db:        db,
			validator: validator.New(),
		},
	}
}

// ArticlesHandler type
type ArticlesHandler struct {
	parent BaseHandler
}

func (ah *ArticlesHandler) getAllArticles(c echo.Context) error {
	coll := &model.Articles{}
	articles := ah.parent.GetAllObjects(&model.Article{}, coll, bson.D{})

	return c.JSON(http.StatusOK, articles)
}

func (ah *ArticlesHandler) getOneArticle(c echo.Context) error {
	id := c.Param("id")
	art := &model.Article{}

	if _, err := ah.parent.GetSingleObject(art, id); err != nil {
		return err
	}

	return c.JSON(http.StatusOK, art)
}

func (ah *ArticlesHandler) createArticle(c echo.Context) error {
	art := &model.Article{}
	c.Bind(art)

	if _, err := ah.parent.CreateObject(art); err != nil {
		return err
	}

	return c.JSON(http.StatusOK, art)
}

func (ah *ArticlesHandler) updateArticle(c echo.Context) error {
	id := c.Param("id")
	model := &model.Article{}

	art, err := ah.parent.GetSingleObject(model, id)
	if err != nil {
		return err
	}
	DeserializeFromRequest(c.Request(), art)

	if _, err := ah.parent.UpdateObject(art); err != nil {
		return err
	}

	return c.JSON(http.StatusOK, art)
}

func (ah *ArticlesHandler) removeArticle(c echo.Context) error {
	id := c.Param("id")
	model := &model.Article{}
	
	art, err := ah.parent.GetSingleObject(model, id)
	if err != nil {
		return err
	}

	if err := ah.parent.RemoveObject(art); err != nil {
		return err
	}

	return c.NoContent(http.StatusOK)
}