Many2Many

This plugin lets you manage many-to-many relationships.

Installation

Install the plugin:

npm i @adminforth/many2many

Setting up

Let's say we want to implement a relationship where every apartment can have many realtors and each realtor can have many apartments. We'll also need a junction resource to connect realtors and apartments.

First, create the realtors table and the junction table realtorsAparts:

./schema.prisma

model realtors {
  id            String @id
  name          String
  surname       String
}
model realtorsAparts {
  id            String @id
  realtorId     String
  apartmentId   String
}

Migrate the Prisma schema:

npm run makemigration -- --name add-realtors-and-realtorsAparts; npm run migrate:local

Now create a resource for the realtors:

./resources/realtors.ts

import { AdminForthDataTypes, AdminForthResourceInput } from 'adminforth';

export default {
  dataSource: 'maindb',
  table: 'realtors',
  resourceId: 'realtors', 
  label: 'Realtors',
  recordLabel: (r) => ` ${r.name}`,
  columns: [
    {
      name: 'id',
      type: AdminForthDataTypes.STRING,
      label: 'Identifier',
      showIn: {
        list: false,
        edit: false,
        create: false,
      },
      primaryKey: true,
      fillOnCreate: ({ initialRecord, adminUser }) => Math.random().toString(36).substring(7),
    },
    {
      name: 'name',
      required: true,
      showIn: { all: true },
      type: AdminForthDataTypes.STRING,
      maxLength: 255,
      minLength: 3,
    },
    {
      name: "surname",
      required: true,
      showIn: { all: true },
      type: AdminForthDataTypes.STRING,
      maxLength: 100,
      minLength: 3,
    }
  ],
  options: {
    listPageSize: 12,
    allowedActions: {
      edit: true,
      delete: true,
      show: true,
      filter: true,
    },
  },
} as AdminForthResourceInput;

And one for the junction table realtorsAparts:

./resources/realtorsAparts.ts

import { AdminForthDataTypes, AdminForthResourceInput } from 'adminforth';

export default {
  dataSource: 'maindb',
  table: 'realtorsAparts',
  resourceId: 'realtorsAparts', 
  label: 'Realtors-aparts',
  columns: [
    {
      name: 'id',
      type: AdminForthDataTypes.STRING,
      label: 'Identifier',
      showIn: {
        list: false,
        edit: false,
        create: false,
      },
      primaryKey: true,
      fillOnCreate: ({ initialRecord, adminUser }) => Math.random().toString(36).substring(7),
    },
    {
      name: 'realtorId',
      foreignResource: { 
        resourceId: 'realtors', 
        searchableFields: ['name'], 
        searchIsCaseSensitive: true 
      }
    },
    {
      name: 'apartmentId',
      foreignResource: { 
        resourceId: 'aparts',
        searchableFields: ['title'],
        searchIsCaseSensitive: true 
      }
    },
  ],
  options: {
    listPageSize: 12,
    allowedActions: {
      edit: true,
      delete: true,
      show: true,
      filter: true,
    },
  },
} as AdminForthResourceInput;

Now add the plugin resources to the main config file:

./index.ts

import realtorsResource from './resources/realtors.js';
import realtorsApartsResource from './resources/realtorsAparts.js';

  ...


dataSources: [
    {
      id: 'maindb',
      url: `${process.env.DATABASE_URL}`
    },
  ],
  resources: [
    ...
    realtorsResource,
    realtorsApartsResource
  ]

  ...

  menu: [

    ...
    {
      label: 'Realtors',
      resourceId: 'realtors'
    },
    {
      label: 'Realtors-aparts',
      resourceId: 'realtorsAparts'
    },

    ...

  ]

Finally, add the plugin to the apartments resource:

./resources/apartments.ts

import Many2ManyPlugin from '@adminforth/many2many';

  ...

  plugins: [
    ...

    new Many2ManyPlugin({
      linkedResourceId: 'realtors',
    })

    ...
  ]

  ...

The plugin is set up. Create some records in the realtors table: Now, when creating an apartment, you can select (link) one or more realtors. After saving the record, rows in the junction table are created automatically:

Disable automatic cleanup of the junction table

By default, when you delete a realtor or an apartment, all related rows in the junction table are deleted automatically. To avoid this behavior, add:

  ...

    new Many2ManyPlugin({
      linkedResourceId: 'realtors',
      dontDeleteJunctionRecords: true, // prevents automatic deletion of related junction rows
    })

  ...

Making editable fields for the both resources

There might be cases, when you want to make fields editable on both resources. For these cases you can just create second instance of plugin on the second resource and it will allow you to use this plugin from the both resources.

./resources/apartments.ts

import Many2ManyPlugin from '@adminforth/many2many';

  ...

  plugins: [
    ...

    new Many2ManyPlugin({
      linkedResourceId: 'realtors',
    })

    ...
  ]

  ...

and

./resources/realtors.ts

import Many2ManyPlugin from '@adminforth/many2many';

  ...

  plugins: [
    ...

    new Many2ManyPlugin({
      linkedResourceId: 'aparts',
    })

    ...
  ]

  ...