public commit

app/src/data/entities/query/JoinBuilder.ts

@@ -0,0 +1,51 @@
+import { ManyToManyRelation, ManyToOneRelation } from "../../relations";
+import type { Entity } from "../Entity";
+import type { EntityManager } from "../EntityManager";
+import type { RepositoryQB } from "./Repository";
+
+export class JoinBuilder {
+   private static buildClause(
+      em: EntityManager<any>,
+      qb: RepositoryQB,
+      entity: Entity,
+      withString: string,
+   ) {
+      const relation = em.relationOf(entity.name, withString);
+      if (!relation) {
+         throw new Error(`Relation "${withString}" not found`);
+      }
+
+      return relation.buildJoin(entity, qb, withString);
+   }
+
+   // @todo: returns multiple on manytomany (edit: so?)
+   static getJoinedEntityNames(em: EntityManager<any>, entity: Entity, joins: string[]): string[] {
+      return joins.flatMap((join) => {
+         const relation = em.relationOf(entity.name, join);
+         if (!relation) {
+            throw new Error(`Relation "${join}" not found`);
+         }
+
+         const other = relation.other(entity);
+
+         if (relation instanceof ManyToOneRelation) {
+            return [other.entity.name];
+         } else if (relation instanceof ManyToManyRelation) {
+            return [other.entity.name, relation.connectionEntity.name];
+         }
+
+         return [];
+      });
+   }
+
+   static addClause(em: EntityManager<any>, qb: RepositoryQB, entity: Entity, joins: string[]) {
+      if (joins.length === 0) return qb;
+
+      let newQb = qb;
+      for (const entry of joins) {
+         newQb = JoinBuilder.buildClause(em, newQb, entity, entry);
+      }
+
+      return newQb;
+   }
+}