objection.md

description	cover	coverY
@adminjs/objection	../../.gitbook/assets/objection-baner (1).png	0

Objection

{% hint style="info" %} Before reading this article, make sure you have set up an AdminJS instance using one of the supported Plugins.
Additionally, you should have installed @adminjs/objection as described in Getting started section. {% endhint %}

This guide will assume you have set up Objection using it's documentation.

Before you start connecting your Objection models to AdminJS, we strongly advise to extend it's Model class to include format options and hooks for setting up your timestamps.

You might need to install an additional library ajv-formats:

$ yarn add ajv-formats

{% code title="base-model.ts" %}

import addFormats from 'ajv-formats';
import { AjvValidator, Model } from 'objection';

export abstract class BaseModel extends Model {
  createdAt: string;

  updatedAt: string;

  static createValidator(): AjvValidator {
    return new AjvValidator({
      onCreateAjv: (ajv) => {
        addFormats(ajv);
      },
      options: {
        allErrors: true,
        validateSchema: false,
        ownProperties: true,
      },
    });
  }

  $beforeInsert(): void {
    this.createdAt = new Date().toISOString();
  }

  $beforeUpdate(): void {
    this.updatedAt = new Date().toISOString();
  }
}

{% endcode %}

Office is an example model which extends BaseModel:

{% code title="office.entity.ts" %}

import { BaseModel } from '../base-model.js';
import Manager from './manager.entity.js';

export interface OfficeAddress {
  street: string;
  city: string;
  zipCode: string;
}

class Office extends BaseModel {
  id: number;

  name: string;

  address?: OfficeAddress;

  static tableName = 'offices';

  static jsonSchema = {
    type: 'object',
    required: ['name'],
    properties: {
      id: { type: 'integer' },
      name: { type: 'string', minLength: 1, maxLength: 255 },
      address: {
        type: 'object',
        properties: {
          street: { type: 'string' },
          city: { type: 'string' },
          zipCode: { type: 'string' },
        },
      },
      createdAt: { type: 'string', format: 'date-time' },
      updatedAt: { type: 'string', format: 'date-time' },
    },
  };
}

export default Office;

{% endcode %}

Please note that jsonSchema is necessary for AdminJS to determine your fields and their types.

The rest of the setup is similar to other adapters:

• You must import AdminJSObjection adapter and register it
• You must import the entities you want to use and pass them to AdminJS resources options, you cannot use databases because unfortunately Objection does not expose any connection with all models metadata.

{% code title="app.ts" %}

// ... other imports
import * as AdminJSObjection from '@adminjs/objection'

import { Office } from './office.entity.js'

AdminJS.registerAdapter({
  Resource: AdminJSObjection.Resource,
  Database: AdminJSObjection.Database,
})

// ... other code
const start = async () => {
  const adminOptions = {
    // We pass Office to `resources`
    resources: [Office],
  }
  // Please note that some plugins don't need you to create AdminJS instance manually,
  // instead you would just pass `adminOptions` into the plugin directly,
  // an example would be "@adminjs/hapi"
  const admin = new AdminJS(adminOptions)
  // ... other code
}

start()

{% endcode %}

{% hint style="warning" %} Make sure you have followed Objection documentation and have setup your knexfile and knex instance. {% endhint %}

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