02. Adding resources

Idea of Resources

What is a Resource in AdminJS? - Resource is everything that you can manage (CRUD - create, read, update, destroy). Most often it is a Model from your ORM.

The entire idea od AdminJS is to manage resources of all kinds. It doesn't matter if you use MongoDB with mongoose or PostgreSQL with Sequelize. AdminJS should give you the ability to manage records in all these resources.

Adapters

AdminJS uses Database Adapters in order to handle different kind of resources.

How to use an adapter

1. First, you have to install adapter locally using the npm/yarn.
2. Next, you have to register this adapter using the AdminJS.registerAdapter that AdminJS could recognize resources of its type.

const AdminJS = require('adminjs')
const AdminJSMongoose = require('@adminjs/mongoose')

AdminJS.registerAdapter(AdminJSMongoose)

Passing resources to AdminJS

So you know how to register an adapter - now let's take a look of how to add resources that they can be seen in AdminJS.

You have 2 options:

1. you can either add an entire Database so given Adapter can fetch all resources from it,
2. or you can pass each Resource one by one.

The first option is very easy, but the second allows you to modify the resources, see tutorial: 03. Customize resources.

Both passing entire Database or each Resource can be done via AdminJS options

Example by using the mongoose adapter:

// ...
const AdminJS = require('adminjs')
const AdminJSMongoose = require('@adminjs/mongoose')
const mongoose = require('mongoose')
AdminJS.registerAdapter(AdminJSMongoose)

// Initialize Database along with models - this is how Mongoose does this.
// Most probably you will have them defined in a separate file
const User = mongoose.model('User', { name: String, email: String, surname: String })
const Admin = mongoose.model('Admin', { name: String, email: String})

const run = async () => {
  const mongooseDb = await mongoose.connect('mongodb://localhost:27017/test', { useNewUrlParser: true })

  // Passing resources by giving entire database
  const adminJs = new AdminJS({
    databases: [mongooseDb],
    //... other AdminJSOptions
  })

  // Passing resources one by one,
  // also with an additional options for admin resource
  const adminJs = new AdminJS({
    resources: [User, {
      resource: Admin,
      options: {
        //...
      },
    }],
  })
}

run()
// ...

Way how each Adapter handles initialization differs. That is why make sure to read it's documentation first.

Resources customization

The biggest advantage of using AdminJS is the ability to fully customize how it works. Visit 03. Customize resources to see how you can change the behavior of selected resources.

[Advanced] how it works a.k.a. writing your own Adapters.

Adapter is an object with 2 properties:

• database (class extending BaseDatabase)
• resource (class extending BaseResource)

When you pass SomeDataModel to databases[] or resources[], AdminJS will automatically run all the registered adapters and check their corresponding BaseDatabase.isAdapterFor or BaseResource.isAdapterFor methods. If Adapter returns true AdminJS feeds it (in the constructor) with SomeDataModel.

In order to write your own adapter you have to create these 2 classes and write implementation for all methods like find, create, etc.

HINT: You can also write only a Resource class (extending BaseResource) and pass its instance to AdminJSOptions#resources like this:

class MyApiAdapter extends BaseResource {
  //... all abstract methods from BaseResource
}

const adminJs = new AdminJS({
  resources: [User, {
    resource: new MyApiAdapter(),
    options: {
      //...
    },
  }],
})

AdminJS will see that what you passed is already a BaseDatabase so it wont need to be wrapped by an Adapter.

What's next?

Now let see how you can modify the resource in tutorial 03. Customize resources.