feat: new relation resolver (#9794)

Fix [#240](https://github.com/twentyhq/core-team-issues/issues/240)

packages/twenty-server/src/engine/dataloaders/dataloader.interface.ts

@@ -1,6 +1,11 @@
 import DataLoader from 'dataloader';
 
-import { RelationMetadataLoaderPayload } from 'src/engine/dataloaders/dataloader.service';
+import {
+  RelationLoaderPayload,
+  RelationMetadataLoaderPayload,
+} from 'src/engine/dataloaders/dataloader.service';
+import { FieldMetadataEntity } from 'src/engine/metadata-modules/field-metadata/field-metadata.entity';
+import { ObjectMetadataEntity } from 'src/engine/metadata-modules/object-metadata/object-metadata.entity';
 import { RelationMetadataEntity } from 'src/engine/metadata-modules/relation-metadata/relation-metadata.entity';
 
 export interface IDataloaders {
@@ -8,4 +13,14 @@ export interface IDataloaders {
     RelationMetadataLoaderPayload,
     RelationMetadataEntity
   >;
+
+  relationLoader: DataLoader<
+    RelationLoaderPayload,
+    {
+      sourceObjectMetadata: ObjectMetadataEntity;
+      targetObjectMetadata: ObjectMetadataEntity;
+      sourceFieldMetadata: FieldMetadataEntity;
+      targetFieldMetadata: FieldMetadataEntity;
+    }
+  >;
 }

packages/twenty-server/src/engine/dataloaders/dataloader.module.ts

@@ -1,11 +1,12 @@
 import { Module } from '@nestjs/common';
 
 import { DataloaderService } from 'src/engine/dataloaders/dataloader.service';
+import { FieldMetadataModule } from 'src/engine/metadata-modules/field-metadata/field-metadata.module';
 import { RelationMetadataModule } from 'src/engine/metadata-modules/relation-metadata/relation-metadata.module';
 
 @Module({
+  imports: [RelationMetadataModule, FieldMetadataModule],
   providers: [DataloaderService],
-  imports: [RelationMetadataModule],
   exports: [DataloaderService],
 })
 export class DataloaderModule {}

packages/twenty-server/src/engine/dataloaders/dataloader.service.ts

@@ -5,6 +5,9 @@ import DataLoader from 'dataloader';
 import { FieldMetadataInterface } from 'src/engine/metadata-modules/field-metadata/interfaces/field-metadata.interface';
 
 import { IDataloaders } from 'src/engine/dataloaders/dataloader.interface';
+import { FieldMetadataEntity } from 'src/engine/metadata-modules/field-metadata/field-metadata.entity';
+import { FieldMetadataRelationService } from 'src/engine/metadata-modules/field-metadata/relation/field-metadata-relation.service';
+import { ObjectMetadataEntity } from 'src/engine/metadata-modules/object-metadata/object-metadata.entity';
 import { RelationMetadataEntity } from 'src/engine/metadata-modules/relation-metadata/relation-metadata.entity';
 import { RelationMetadataService } from 'src/engine/metadata-modules/relation-metadata/relation-metadata.service';
 
@@ -16,14 +19,37 @@ export type RelationMetadataLoaderPayload = {
   >;
 };
 
+export type RelationLoaderPayload = {
+  workspaceId: string;
+  fieldMetadata: Pick<
+    FieldMetadataInterface,
+    | 'type'
+    | 'id'
+    | 'objectMetadataId'
+    | 'relationTargetFieldMetadataId'
+    | 'relationTargetObjectMetadataId'
+  >;
+};
+
 @Injectable()
 export class DataloaderService {
   constructor(
     private readonly relationMetadataService: RelationMetadataService,
+    private readonly fieldMetadataRelationService: FieldMetadataRelationService,
   ) {}
 
   createLoaders(): IDataloaders {
-    const relationMetadataLoader = new DataLoader<
+    const relationMetadataLoader = this.createRelationMetadataLoader();
+    const relationLoader = this.createRelationLoader();
+
+    return {
+      relationMetadataLoader,
+      relationLoader,
+    };
+  }
+
+  private createRelationMetadataLoader() {
+    return new DataLoader<
       RelationMetadataLoaderPayload,
       RelationMetadataEntity
     >(async (dataLoaderParams: RelationMetadataLoaderPayload[]) => {
@@ -40,9 +66,30 @@ export class DataloaderService {
 
       return relationsMetadataCollection;
     });
+  }
 
-    return {
-      relationMetadataLoader,
-    };
+  private createRelationLoader() {
+    return new DataLoader<
+      RelationLoaderPayload,
+      {
+        sourceObjectMetadata: ObjectMetadataEntity;
+        targetObjectMetadata: ObjectMetadataEntity;
+        sourceFieldMetadata: FieldMetadataEntity;
+        targetFieldMetadata: FieldMetadataEntity;
+      }
+    >(async (dataLoaderParams: RelationLoaderPayload[]) => {
+      const workspaceId = dataLoaderParams[0].workspaceId;
+      const fieldMetadataItems = dataLoaderParams.map(
+        (dataLoaderParam) => dataLoaderParam.fieldMetadata,
+      );
+
+      const fieldMetadataRelationCollection =
+        await this.fieldMetadataRelationService.findCachedFieldMetadataRelation(
+          fieldMetadataItems,
+          workspaceId,
+        );
+
+      return fieldMetadataRelationCollection;
+    });
   }
 }