tethys.backend/app/Models/Subject.ts

import { column, SnakeCaseNamingStrategy, manyToMany, ManyToMany, beforeCreate, beforeUpdate } from '@ioc:Adonis/Lucid/Orm';
import BaseModel from './BaseModel';

import { DateTime } from 'luxon';
import dayjs from 'dayjs';
import Dataset from './Dataset';

export default class Subject extends BaseModel {
    public static namingStrategy = new SnakeCaseNamingStrategy();
    public static table = 'dataset_subjects';
    public static selfAssignPrimaryKey = false;

    @column({
        isPrimary: true,
    })
    public id: number;

    @column({})
    public language: string;

    @column({})
    public type: string;

    @column({})
    public value: string;

    @column({})
    public external_key: string;

    @column.dateTime({
        serialize: (value: Date | null) => {
            return value ? dayjs(value).format('MMMM D YYYY HH:mm a') : value;
        },
        autoCreate: true,
    })
    public created_at: DateTime;

    @column.dateTime({
        serialize: (value: Date | null) => {
            return value ? dayjs(value).format('MMMM D YYYY HH:mm a') : value;
        },
        autoCreate: true,
        autoUpdate: true,
    })
    public updated_at: DateTime;

    @beforeCreate()
    @beforeUpdate()
    public static async resetDate(role) {
        role.created_at = this.formatDateTime(role.created_at);
        role.updated_at = this.formatDateTime(role.updated_at);
    }

    private static formatDateTime(datetime) {
        let value = new Date(datetime);
        return datetime
            ? value.getFullYear() +
                  '-' +
                  (value.getMonth() + 1) +
                  '-' +
                  value.getDate() +
                  ' ' +
                  value.getHours() +
                  ':' +
                  value.getMinutes() +
                  ':' +
                  value.getSeconds()
            : datetime;
    }

    @manyToMany(() => Dataset, {
        pivotForeignKey: 'subject_id',
        pivotRelatedForeignKey: 'document_id',
        pivotTable: 'link_dataset_subjects',
    })
    public datasets: ManyToMany<typeof Dataset>;
}