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
    })

  ...