# payload-relationship-enhancer

This is a very early release of a plugin designed to enhance the relationships within payload to do two things:

1. Provide `referential integrity` through deletes - i.e. if A references B and then B is deleted, A should no longer reference A
2. Provide `bi-directional` relationships - i.e. if A references B, allow B to reference A and keep them in sync.

**Motivation**: if you have used keystonejs you know why, but more importantly, this stops gymnastics at query time to try and reverse lookup a relationship and instead builds it into the GraphQL / REST schema

## A word of warning

This was written by someone who is bad at coding, and until a week ago had never used Mongo or Payload. Performance is probably bad and it might delete all your relationships.

**I am almost certain this will not work properly for everyone and in every case, please leave an issue with details about how your relationships were setup!**

[Payload would appear to be considering bi-directional relationships as a core feature](https://discord.com/channels/967097582721572934/1140969904942628874) (although it is not on roadmap) in the future, so this should be seen as a stop-gap for applications prior to its official implementation.

## Getting started

1. `bun add payload-relationship-enhancer`

2. update your payload config like this:

```
import RelationshipEnhancerPlugin from "payload-relationship-enhancer";

plugins: [payloadCloud(), RelationshipEnhancerPlugin],
```

3. configure it like this:

```
    {
      type: "relationship",
      relationTo: "c",
      hasMany: true,
      name: "amixedblocks",
      custom: {
        relationshipEnhancer: {
          relationshipIntegrity: true,
          biDirectional: [
            {
              relationTo: "c", // must match one or more of the things in relationTo
              path: "cmixedblocks", // this is the path of the field on c that is ALSO a relationship field AND has a biDirectional config pointing back here
            },
            ...
          ],
        },
      },
    },
```

## Config type is

```
        {
          relationshipIntegrity?: boolean,
          biDirectional?: [
            {
              relationTo: string;
              path: string;
            },
            ...
          ],
        }
```

## Limitations / TODO

- Currently any relationship field nested under an array will be ignored by this plugin, groups and tabs and blocks should be fine.
- Only Mongo is supported as a database, it is very possible to add Postgres.
- Support for localised relationship fields is not yet there
- The changes made by this plugin do NOT trigger lifecycle hooks - i.e. if you have a bi-directional relationship between A and B, and set the value in A to some B document, the plugin will update a B document but no update hook will run - this is because we use the mongoose adapter directly and I am not sure exactly how to manually trigger updates.
- This really needs some tests
- I don't think the structure of this plugin follows best practice
- Should add some plugin init config params for profiling performance
- Better docs
- The config will let you point two fields on 1 collection to 1 field on another - this breaks stuff. need to sanitise out in config check step
- Some janky stuff with 'required' relationship fields that needs to be tested out

## Contributing

Please do.

## Dev mode

- `bun install`
- `bun run dev`

Mongo & payload will start - localhost:3000. Payload user is `test@test.com` with password `test`