CategoryEntity.ts

import {
    BeforeCreate,
    BeforeUpdate,
    Collection,
    Entity,
    EntityManager,
    EntityRepositoryType,
    ManyToOne,
    OneToMany,
    Property,
} from '@mikro-orm/core';
import { EntityBase } from '@database/EntityBase';
import { CategoryRepository } from '@database/repositories/CategoryRepository';
import { IsDefined, IsOptional, IsString, IsUUID, Length, Validate } from 'class-validator';
import ExistsInTable from '@validators/ExistsInTable';
import { AdEntity } from '@database/entities/AdEntity';

@Entity({ customRepository: () => CategoryRepository })
export class CategoryEntity extends EntityBase {
    [EntityRepositoryType]?: CategoryRepository;

    @Property({ length: 100, nullable: false, type: 'varchar(100)' })
    @IsDefined()
    @IsString()
    @Length(2, 100)
    name: string;

    @Property({ length: 200, nullable: false, type: 'varchar(200)' })
    slug: string;

    @Property({ nullable: true, default: null, type: 'text' })
    @IsOptional()
    @IsString()
    @Length(1, 1000)
    description?: string;

    @Property({ persist: false, nullable: true })
    @IsOptional()
    @IsUUID()
    @Validate(ExistsInTable, ['CategoryEntity', 'id'])
    parentId?: string | null;

    @ManyToOne({
        entity: () => CategoryEntity,
        // mappedBy: 'children',
        nullable: true,
    })
    parent?: CategoryEntity;

    @OneToMany({
        entity: () => CategoryEntity,
        mappedBy: 'parent',
        nullable: true,
    })
    children? = new Collection<CategoryEntity>(this);

    @OneToMany('AdEntity', 'category')
    ads = new Collection<AdEntity>(this);

    @BeforeCreate()
    @BeforeUpdate()
    async makeSlug({ em }: { entity: CategoryEntity; em: EntityManager }) {
        if (!this.slug) {
            const slugBase = this.name
                .toLowerCase()
                .replace(/[^a-z0-9]/g, '-')
                .replace(/-+/g, '-')
                .trim();

            let slug = slugBase;
            let count = 0;
            let iterator = 1;

            do {
                count = await em.count(CategoryEntity, { slug });
                if (count > 0) {
                    console.log(`${slug} already exists`);
                    slug = `${slugBase}-${iterator}`;
                    iterator++;
                }
            } while (count > 0);
            this.slug = slug;
        }
    }
}