UpdateBlog.go

func (s *BlogServiceServer) UpdateBlog(ctx context.Context, req *blogpb.UpdateBlogReq) (*blogpb.UpdateBlogRes, error) {
	// Get the blog data from the request
	blog := req.GetBlog()

	// Convert the Id string to a MongoDB ObjectId
	oid, err := primitive.ObjectIDFromHex(blog.GetId())
	if err != nil {
		return nil, status.Errorf(
			codes.InvalidArgument,
			fmt.Sprintf("Could not convert the supplied blog id to a MongoDB ObjectId: %v", err),
		)
	}

	// Convert the data to be updated into an unordered Bson document
	update := bson.M{
		"authord_id": blog.GetAuthorId(),
		"title":      blog.GetTitle(),
		"content":    blog.GetContent(),
	}

	// Convert the oid into an unordered bson document to search by id
	filter := bson.M{"_id": oid}

	// Result is the BSON encoded result
	// To return the updated document instead of original we have to add options.
	result := blogdb.FindOneAndUpdate(ctx, filter, bson.M{"$set": update}, options.FindOneAndUpdate().SetReturnDocument(1))

	// Decode result and write it to 'decoded'
	decoded := BlogItem{}
	err = result.Decode(&decoded)
	if err != nil {
		return nil, status.Errorf(
			codes.NotFound,
			fmt.Sprintf("Could not find blog with supplied ID: %v", err),
		)
	}
	return &blogpb.UpdateBlogRes{
		Blog: &blogpb.Blog{
			Id:       decoded.ID.Hex(),
			AuthorId: decoded.AuthorID,
			Title:    decoded.Title,
			Content:  decoded.Content,
		},
	}, nil
}