feat: support hasMany virtual relationship fields

packages/payload/src/fields/config/sanitize.ts

@@ -7,17 +7,21 @@ import type {
   SanitizedJoins,
 } from '../../collections/config/types.js'
 import type { Config, SanitizedConfig } from '../../config/types.js'
+import type { GlobalConfig } from '../../globals/config/types.js'
 import type { Field } from './types.js'
 
 import {
   DuplicateFieldName,
+  InvalidConfiguration,
   InvalidFieldName,
   InvalidFieldRelationship,
   MissingEditorProp,
   MissingFieldType,
 } from '../../errors/index.js'
 import { ReservedFieldName } from '../../errors/ReservedFieldName.js'
+import { flattenAllFields } from '../../utilities/flattenAllFields.js'
 import { formatLabels, toWords } from '../../utilities/formatLabels.js'
+import { getFieldByPath } from '../../utilities/getFieldByPath.js'
 import { baseBlockFields } from '../baseFields/baseBlockFields.js'
 import { baseIDField } from '../baseFields/baseIDField.js'
 import { baseTimezoneField } from '../baseFields/timezone/baseField.js'
@@ -31,13 +35,19 @@ import {
   reservedVerifyFieldNames,
 } from './reservedFieldNames.js'
 import { sanitizeJoinField } from './sanitizeJoinField.js'
-import { fieldAffectsData as _fieldAffectsData, fieldIsLocalized, tabHasName } from './types.js'
+import {
+  fieldAffectsData as _fieldAffectsData,
+  fieldIsLocalized,
+  fieldIsVirtual,
+  tabHasName,
+} from './types.js'
 
 type Args = {
   collectionConfig?: CollectionConfig
   config: Config
   existingFieldNames?: Set<string>
   fields: Field[]
+  globalConfig?: GlobalConfig
   /**
    * Used to prevent unnecessary sanitization of fields that are not top-level.
    */
@@ -72,6 +82,7 @@ export const sanitizeFields = async ({
   config,
   existingFieldNames = new Set(),
   fields,
+  globalConfig,
   isTopLevelField = true,
   joinPath = '',
   joins,
@@ -416,6 +427,51 @@ export const sanitizeFields = async ({
 
       fields.splice(++i, 0, timezoneField)
     }
+
+    if ('virtual' in field && typeof field.virtual === 'string') {
+      const virtualField = field
+      const fields = (collectionConfig || globalConfig)?.fields
+      if (fields) {
+        let flattenFields = flattenAllFields({ fields })
+        const paths = field.virtual.split('.')
+        let isHasMany = false
+
+        for (const [i, segment] of paths.entries()) {
+          const field = flattenFields.find((e) => e.name === segment)
+          if (!field) {
+            break
+          }
+
+          if (field.type === 'group' || field.type === 'tab' || field.type === 'array') {
+            flattenFields = field.flattenedFields
+          } else if (
+            (field.type === 'relationship' || field.type === 'upload') &&
+            i !== paths.length - 1 &&
+            typeof field.relationTo === 'string'
+          ) {
+            if (
+              field.hasMany &&
+              (virtualField.type === 'text' ||
+                virtualField.type === 'number' ||
+                virtualField.type === 'select')
+            ) {
+              if (isHasMany) {
+                throw new InvalidConfiguration(
+                  `Virtual field ${virtualField.name} in ${globalConfig ? `global ${globalConfig.slug}` : `collection ${collectionConfig?.slug}`} references 2 or more hasMany relationships on the path ${virtualField.virtual} which is not allowed.`,
+                )
+              }
+
+              isHasMany = true
+              virtualField.hasMany = true
+            }
+            const relatedCollection = config.collections?.find((e) => e.slug === field.relationTo)
+            if (relatedCollection) {
+              flattenFields = flattenAllFields({ fields: relatedCollection.fields })
+            }
+          }
+        }
+      }
+    }
   }
 
   return fields

packages/payload/src/fields/hooks/afterRead/virtualFieldPopulationPromise.ts

@@ -8,6 +8,7 @@ export const virtualFieldPopulationPromise = async ({
   draft,
   fallbackLocale,
   fields,
+  hasMany,
   locale,
   overrideAccess,
   ref,
@@ -19,12 +20,14 @@ export const virtualFieldPopulationPromise = async ({
   draft: boolean
   fallbackLocale: string
   fields: FlattenedField[]
+  hasMany?: boolean
   locale: string
   name: string
   overrideAccess: boolean
   ref: any
   req: PayloadRequest
   segments: string[]
+  shift?: boolean
   showHiddenFields: boolean
   siblingDoc: Record<string, unknown>
 }): Promise<void> => {
@@ -42,7 +45,14 @@ export const virtualFieldPopulationPromise = async ({
 
   // Final step
   if (segments.length === 0) {
-    siblingDoc[name] = currentValue
+    if (hasMany) {
+      if (!Array.isArray(siblingDoc[name])) {
+        siblingDoc[name] = []
+      }
+      ;(siblingDoc[name] as any[]).push(currentValue)
+    } else {
+      siblingDoc[name] = currentValue
+    }
     return
   }
 
@@ -74,26 +84,8 @@ export const virtualFieldPopulationPromise = async ({
 
   if (
     (currentField.type === 'relationship' || currentField.type === 'upload') &&
-    typeof currentField.relationTo === 'string' &&
-    !currentField.hasMany
+    typeof currentField.relationTo === 'string'
   ) {
-    let docID: number | string
-
-    if (typeof currentValue === 'object' && currentValue) {
-      docID = currentValue.id
-    } else {
-      docID = currentValue
-    }
-
-    if (segments[0] === 'id' && segments.length === 0) {
-      siblingDoc[name] = docID
-      return
-    }
-
-    if (typeof docID !== 'string' && typeof docID !== 'number') {
-      return
-    }
-
     const select = {}
     let currentSelectRef: any = select
     const currentFields = req.payload.collections[currentField.relationTo]?.config.flattenedFields
@@ -112,6 +104,91 @@ export const virtualFieldPopulationPromise = async ({
       }
     }
 
+    if (currentField.hasMany) {
+      if (!Array.isArray(currentValue)) {
+        return
+      }
+
+      const docIDs = currentValue
+        .map((e) => {
+          if (!e) {
+            return null
+          }
+          if (typeof e === 'object') {
+            return e.id
+          }
+          return e
+        })
+        .filter((e) => typeof e === 'string' || typeof e === 'number')
+
+      if (segments[0] === 'id' && segments.length === 0) {
+        siblingDoc[name] = docIDs
+        return
+      }
+
+      const collectionSlug = currentField.relationTo
+
+      const populatedDocs = await Promise.all(
+        docIDs.map((docID) => {
+          return req.payloadDataLoader.load(
+            createDataloaderCacheKey({
+              collectionSlug,
+              currentDepth: 0,
+              depth: 0,
+              docID,
+              draft,
+              fallbackLocale,
+              locale,
+              overrideAccess,
+              select,
+              showHiddenFields,
+              transactionID: req.transactionID as number,
+            }),
+          )
+        }),
+      )
+
+      for (const doc of populatedDocs) {
+        if (!doc) {
+          continue
+        }
+
+        await virtualFieldPopulationPromise({
+          name,
+          draft,
+          fallbackLocale,
+          fields: req.payload.collections[currentField.relationTo]!.config.flattenedFields,
+          hasMany: true,
+          locale,
+          overrideAccess,
+          ref: doc,
+          req,
+          segments: [...segments],
+          showHiddenFields,
+          siblingDoc,
+        })
+      }
+
+      return
+    }
+
+    let docID: number | string
+
+    if (typeof currentValue === 'object' && currentValue) {
+      docID = currentValue.id
+    } else {
+      docID = currentValue
+    }
+
+    if (segments[0] === 'id' && segments.length === 0) {
+      siblingDoc[name] = docID
+      return
+    }
+
+    if (typeof docID !== 'string' && typeof docID !== 'number') {
+      return
+    }
+
     const populatedDoc = await req.payloadDataLoader.load(
       createDataloaderCacheKey({
         collectionSlug: currentField.relationTo,
@@ -137,6 +214,7 @@ export const virtualFieldPopulationPromise = async ({
       draft,
       fallbackLocale,
       fields: req.payload.collections[currentField.relationTo]!.config.flattenedFields,
+      hasMany,
       locale,
       overrideAccess,
       ref: populatedDoc,

packages/payload/src/globals/config/sanitize.ts

@@ -81,6 +81,7 @@ export const sanitizeGlobal = async (
   global.fields = await sanitizeFields({
     config,
     fields: global.fields,
+    globalConfig: global,
     parentIsLocalized: false,
     richTextSanitizationPromises,
     validRelationships,

test/database/getConfig.ts

@@ -607,6 +607,16 @@ export const getConfig: () => Partial<Config> = () => ({
           type: 'text',
           virtual: 'post.title',
         },
+        {
+          name: 'postsTitles',
+          type: 'text',
+          virtual: 'posts.title',
+        },
+        {
+          name: 'postCategoriesTitles',
+          type: 'text',
+          virtual: 'post.categories.title',
+        },
         {
           name: 'postTitleHidden',
           type: 'text',
@@ -643,6 +653,12 @@ export const getConfig: () => Partial<Config> = () => ({
           type: 'relationship',
           relationTo: 'posts',
         },
+        {
+          name: 'posts',
+          type: 'relationship',
+          relationTo: 'posts',
+          hasMany: true,
+        },
         {
           name: 'customID',
           type: 'relationship',

test/database/int.spec.ts

@@ -2988,6 +2988,58 @@ describe('database', () => {
       })
       expect(docs).toHaveLength(1)
     })
+
+    it('should automatically add hasMany: true to a virtual field that references a hasMany relationship', () => {
+      const field = payload.collections['virtual-relations'].config.fields.find(
+        // eslint-disable-next-line jest/no-conditional-in-test
+        (each) => 'name' in each && each.name === 'postsTitles',
+      )!
+
+      // eslint-disable-next-line jest/no-conditional-in-test
+      expect('hasMany' in field && field.hasMany).toBe(true)
+    })
+
+    it('should the value populate with hasMany: true relationship field', async () => {
+      await payload.delete({ collection: 'categories', where: {} })
+      await payload.delete({ collection: 'posts', where: {} })
+      await payload.delete({ collection: 'virtual-relations', where: {} })
+
+      const post1 = await payload.create({ collection: 'posts', data: { title: 'post 1' } })
+      const post2 = await payload.create({ collection: 'posts', data: { title: 'post 2' } })
+
+      const res = await payload.create({
+        collection: 'virtual-relations',
+        depth: 0,
+        data: { posts: [post1.id, post2.id] },
+      })
+      expect(res.postsTitles).toEqual(['post 1', 'post 2'])
+    })
+
+    it('should the value populate with nested hasMany: true relationship field', async () => {
+      await payload.delete({ collection: 'categories', where: {} })
+      await payload.delete({ collection: 'posts', where: {} })
+      await payload.delete({ collection: 'virtual-relations', where: {} })
+
+      const category_1 = await payload.create({
+        collection: 'categories',
+        data: { title: 'category 1' },
+      })
+      const category_2 = await payload.create({
+        collection: 'categories',
+        data: { title: 'category 2' },
+      })
+      const post1 = await payload.create({
+        collection: 'posts',
+        data: { title: 'post 1', categories: [category_1.id, category_2.id] },
+      })
+
+      const res = await payload.create({
+        collection: 'virtual-relations',
+        depth: 0,
+        data: { post: post1.id },
+      })
+      expect(res.postCategoriesTitles).toEqual(['category 1', 'category 2'])
+    })
   })
 
   it('should convert numbers to text', async () => {