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  • Forest Admin
  • Getting started
    • How it works
    • Quick start
    • Install
      • Create your agent
      • Expose an HTTP endpoint
        • For standalone agents
        • On Express
        • On Koa
        • On Fastify
        • On NestJS
      • Autocompletion & Typings
      • Troubleshooting
    • Migrating legacy agents
      • What's new
      • Pre-requisites
      • Recommendations
      • Migration steps
        • Run new agent in parallel
        • Configure database connection
        • Code transformations
          • API Charts
          • Live Queries
          • Smart Charts
          • Route overrides
          • Smart Actions
          • Smart Fields
          • Smart Relationships
          • Smart Segments
        • Compare schemas
        • Swap agents
      • Post-migration
        • Dropping Sequelize
        • Optimize your agent
  • Data Sources
    • Getting Started
      • Collection selection
      • Naming conflicts
      • Cross-data source relationships
      • Query interface and Native Queries
        • Fields and projections
        • Filters
        • Aggregations
    • Provided data sources
      • SQL (without ORM)
      • Sequelize
      • Mongoose
      • MongoDB
    • Write your own
      • Replication strategy
        • Persistent cache
        • Updating the replica
          • Scheduled rebuilds
          • Change polling
          • Push & Webhooks
        • Schema & References
        • Write handlers
      • Translation strategy
        • Structure declaration
        • Capabilities declaration
        • Read implementation
        • Write implementation
        • Intra-data source Relationships
      • Contribute
  • Agent customization
    • Getting Started
    • Actions
      • Scope and context
      • Result builder
      • Static Forms
      • Widgets in Forms
      • Dynamic Forms
      • Form layout customization
      • Related data invalidation
    • Charts
      • Value
      • Objective
      • Percentage
      • Distribution
      • Leaderboard
      • Time-based
    • Fields
      • Add fields
      • Move, rename and remove fields
      • Override binary field mode
      • Override writing behavior
      • Override filtering behavior
      • Override sorting behavior
      • Validation
    • Hooks
      • Collection hook
      • Collection override
    • Pagination
    • Plugins
      • Provided plugins
        • AWS S3
        • Advanced Export
        • Flattener
      • Write your own
    • Relationships
      • To a single record
      • To multiple records
      • Computed foreign keys
      • Under the hood
    • Search
    • Segments
  • Frontend customization
    • Smart Charts
      • Create a table chart
      • Create a bar chart
      • Create a cohort chart
      • Create a density map
    • Smart Views
      • Create a Map view
      • Create a Calendar view
      • Create a Shipping view
      • Create a Gallery view
      • Create a custom tinder-like validation view
      • Create a custom moderation view
  • Deploying to production
    • Environments
      • Deploy on AWS
      • Deploy on Heroku
      • Deploy on GCP
      • Deploy on Ubuntu
      • Deploy on Azure
    • Development workflow
    • Using branches
    • Deploying your changes
    • Forest Admin CLI commands
      • init
      • login
      • branch
      • switch
      • set-origin
      • push
      • environments:create
      • environments:reset
      • deploy
  • Under the hood
    • .forestadmin-schema.json
    • Data Model
      • Typing
      • Relationships
    • Security & Privacy
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  1. Agent customization

Relationships

This is the official documentation of the @forestadmin/agent Node.js agent.

When relationships are defined during the customization step, Forest Admin Collections act as if the 2 Collections were natively linked at the data source level.

You may have noticed that relationships within a data source are configured out of the box, so you won't need to define those.

However, you may want to create additional intra and cross data source relationships to:

  • help users navigate within your admin panel,

  • create charts that use data from multiple data sources,

  • let users filter, use scopes, or segment with conditions that cross data source boundaries.

Minimal example

agent.customizeCollection('towns', collection =>
  collection
    // Towns belong to 1 country
    .addManyToOneRelation('country', 'countries', { foreignKey: 'country_id' })

    // Towns have 1 mayor
    .addOneToOneRelation('mayor', 'mayors', { originKey: 'town_id' })

    // Towns have multiple inhabitants
    .addOneToManyRelation('inhabitants', 'people', { originKey: 'town_id' })

    // Towns electricity is supplied by power plants that are shared with other towns
    .addManyToManyRelation('energyProviders', 'powerPlants', 'utilityContracts', {
      originKey: 'town_id',
      foreignKey: 'power_plant_id',
    })

    // Towns have a list of honorary citizen that is retrievable through a public API
    .addExternalRelation('honoraryCitizen', {
      schema: { firstName: 'String', lastName: 'String' },
      listRecords: async ({ id }) => {
        const response = await axios.get(
          `https://api.mytown.com/cities/${id}/honorary-citizen`,
        );
        return response.body;
      },
    }),
);
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Last updated 1 year ago

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