45-Nodejs Course 2023: Database Models: Default Values

// src/core/database/model/model.ts
import { Document, ModelDocument } from "./types";

export default abstract class Model extends CrudModel {
  // ...
  /**
   * Define Default value data that will be merged with the models' data
   * on the create process
   */
  public defaultValue: Document = {};
}

// src/core/database/model/model.ts
import { Document, ModelDocument } from "./types";
import Is from "@mongez/supportive-is";import {
  areEqual,
  except,
  get,
  merge,
  only,
  set,
} from "@mongez/reinforcements";

export default abstract class Model extends CrudModel {
  // ...

  /**
   * Perform saving operation either by updating or creating a new record in database
   */
  public async save(mergedData: Document = {}) {
    this.merge(mergedData);

    // check if the data contains the primary id column
    if (this.data._id && !this.isRestored) {
      // perform an update operation
      // check if the data has changed
      // if not changed, then do not do anything
      if (areEqual(this.originalData, this.data)) return;

      this.data.updatedAt = new Date();

      await queryBuilder.update(
        this.getCollectionName(),
        {
          _id: this.data._id,
        },
        this.data,
      );
    } else {
      // creating a new document in the database
      const generateNextId =
        this.getStaticProperty("generateNextId").bind(Model);

      // check for default values and merge it with the data
      this.checkDefaultValues();

      // if the column does not exist, then create it
      if (!this.data.id) {
        this.data.id = await generateNextId();
      }

      const now = new Date();

      // if the column does not exist, then create it
      if (!this.data.createdAt) {
        this.data.createdAt = now;
      }

      // if the column does not exist, then create it
      if (!this.data.updatedAt) {
        this.data.updatedAt = now;
      }

      this.data = await queryBuilder.create(
        this.getCollectionName(),
        this.data,
      );
    }
  }

  /**
   * Check for default values
   */
  protected checkDefaultValues() {
    // if default value is empty, then do nothing
    if (Is.empty(this.defaultValue)) return;

    // merge the data with default value
    this.data = merge(this.defaultValue, this.data);
  }
}

// src/app/users/models/user.ts

import { Model } from "core/database";
import { Document } from "core/database/model/types";

export default class User extends Model {
  /**
   * Collection name
   */
  public static collectionName = "users";

  /**
   * {@inheritDoc}
   */
  public defaultValue: Document = {
    published: true,
  };
}

// src/app/users/routes.ts
import User from './models/user';

const user = await User.create({
  name: 'hasan',
});

console.log(user.data); // {id: 1, name: 'hasan', published: true, _id: '...', createdAt: '...', updatedAt: '...'}