feat: add additional attributes helpers

BREAKING CHANGE: additionalAttributes option format changed

README.md

@@ -126,15 +126,45 @@ Additional attributes can be populated in the read views. For example one can ad
 
 ```ts
 crud('/admin/categories', actions, {
-  additionalAttributes: async category => {
-    return {
-      postsCount: await Post.count({ categoryId: category.id })
-    }
+  additionalAttributes: {
+    postsCount: category => Post.count({ categoryId: category.id })
   },
   additionalAttributesConcurrency: 10 // 10 queries Post.count will be perform at the same time
 })
 ```
 
+additionalAttributes function parameters are:
+- the current row
+- an object: `{rows, req}` where rows are all page rows and req is the express request.
+
+Similarly to how react-admin deals with resource references, express-crud-router provides additional field helpers:
+- `populateReference`
+- `populateReferenceMany`
+- `populateReferenceManyCount`
+- `populateReferenceOne`
+
+Using additionalAttributes with `populateReferenceManyCount` or `populateReferenceOne` can be useful instead of using react-admin ReferenceManyCount and ReferenceOne as they are often used in list views and generate one HTTP query per row.
+
+```ts
+crud<number, { id: number }>('/users', {
+  get: jest.fn().mockResolvedValue({
+    rows: [{ id: 1 }, { id: 2 } , { id: 3 }],
+    count: 2
+  }),
+}, {
+  additionalAttributes: {
+    posts: populateReferenceMany({
+      fetchAll: async () => [
+        {id: 10, authorId: 1},
+        {id: 11, authorId: 1},
+        {id: 12, authorId: 2},
+      ],
+      target: 'authorId'
+    })
+  }
+})
+```
+
 ### Custom behavior & other ORMs
 
 ```ts

src/additionalAttributeHelpers.ts

@@ -0,0 +1,129 @@
+import { Request } from "express"
+
+type RaRecord = {id: string | number}
+
+export const populateReference = <R extends RaRecord, T extends RaRecord>({fetchAll,source, target = 'id'}: {
+  fetchAll: (rows: R[]) => Promise<T[]>,
+  source: keyof R
+  target?: keyof T
+  }) => {
+    const cache = new Cache()
+
+    return async (record: R, {rows, req}: {rows: R[], req: Request}) => {
+      let referencesByTarget = cache.get(req)
+
+      if (!referencesByTarget) {
+        const references = await fetchAll(rows)
+
+        referencesByTarget = references.reduce((referencesByTarget, reference) => {
+          referencesByTarget[reference[target ?? 'id'] as unknown as string] = reference
+          return referencesByTarget
+        }, {} as Record<string, T>)
+
+        cache.set(req, referencesByTarget)
+      }
+
+      return referencesByTarget[record[source] as unknown as string]
+  }
+}
+
+export const populateReferenceMany = <R extends RaRecord, T extends RaRecord>({fetchAll,source= 'id', target }: {
+  fetchAll: (rows: R[]) => Promise<T[]>,
+  source?: keyof R
+  target: keyof T
+  }) => {
+    const cache = new Cache()
+
+    return async (record: R, {rows, req}: {rows: R[], req: Request}) => {
+      let referencesByTarget = cache.get(req)
+
+      if (!referencesByTarget) {
+        const references = await fetchAll(rows)
+
+        referencesByTarget = references.reduce((referencesByTarget, reference) => {
+          if (!referencesByTarget[reference[target] as unknown as string]) {
+            referencesByTarget[reference[target] as unknown as string] = []
+          }
+          referencesByTarget[reference[target] as unknown as string].push(reference)
+          return referencesByTarget
+        }, {} as Record<string, T[]>)
+
+        cache.set(req, referencesByTarget)
+      }
+      return referencesByTarget[record[source ?? 'id'] as unknown as string] ?? []
+  }
+}
+
+
+export const populateReferenceManyCount = <R extends RaRecord, T extends RaRecord>({fetchAll,source= 'id', target }: {
+  fetchAll: (rows: R[]) => Promise<T[]>,
+  source?: keyof R
+  target: keyof T
+  }) => {
+    const cache = new Cache()
+
+    return async (record: R, {rows, req}: {rows: R[], req: Request}) => {
+      let referencesByTarget = cache.get(req)
+
+      if (!referencesByTarget) {
+        const references = await fetchAll(rows)
+
+        referencesByTarget = references.reduce((referencesByTarget, reference) => {
+          if (!referencesByTarget[reference[target] as unknown as string]) {
+            referencesByTarget[reference[target] as unknown as string] = []
+          }
+          referencesByTarget[reference[target] as unknown as string].push(reference)
+          return referencesByTarget
+        }, {} as Record<string, T[]>)
+
+        cache.set(req, referencesByTarget)
+      }
+
+      return referencesByTarget[record[source ?? 'id'] as unknown as string]?.length ?? 0
+  }
+}
+
+export const populateReferenceOne = <R extends RaRecord, T extends RaRecord>({fetchAll,source= 'id', target }: {
+  fetchAll: (rows: R[]) => Promise<T[]>,
+  source?: keyof R
+  target: keyof T,
+  }) => {
+    const getAllReferences = populateReferenceMany({fetchAll,source, target})
+
+    return async (record: R, {rows, req}: {rows: R[], req: Request}) => {
+      const references = await getAllReferences(record, {rows,req})
+      return references[0]
+  }
+}
+
+let id = 1
+
+class Cache {
+  private id: number
+
+  constructor() {
+    this.id = id
+    id += 1
+  }
+
+  get = (req: any) =>{
+    if (!req.locals?.expressCrudRouter){
+      return undefined
+    }
+
+    return req.locals.expressCrudRouter[this.id]
+  }
+
+  set = (req: any, value: any) => {
+    req = req
+
+    if (!req.locals) {
+      req.locals = {}
+    }
+    if (!req.locals.expressCrudRouter) {
+      req.locals.expressCrudRouter = {}
+    }
+
+    req.locals.expressCrudRouter[this.id] = value
+  }
+}

src/getList/index.ts

@@ -15,7 +15,7 @@ export type Get<R> = (conf: {
 
 export interface GetListOptions<R> {
   filters: FiltersOption
-  additionalAttributes: (record: R) => object | Promise<object>
+  additionalAttributes: Record<string, (record: R, context: {rows: R[], req: Request}) => any>
   additionalAttributesConcurrency: number
 }
 
@@ -40,7 +40,7 @@ export const getMany = <R>(
     setGetListHeaders(res, offset, count, rows.length)
     res.json(
       options?.additionalAttributes
-        ? await computeAdditionalAttributes(options.additionalAttributes, options.additionalAttributesConcurrency ?? 1)(rows)
+        ? await computeAdditionalAttributes(options.additionalAttributes, options.additionalAttributesConcurrency ?? 1, req)(rows)
         : rows
     )
 
@@ -84,10 +84,16 @@ const getFilter = async (
 
 
 const computeAdditionalAttributes =
-  <R>(additionalAttributes: GetListOptions<R>["additionalAttributes"], concurrency: number) => {
+  <R>(additionalAttributes: GetListOptions<R>["additionalAttributes"], concurrency: number, req: Request) => {
     const limit = pLimit(concurrency)
 
-    return (records: R[]) => Promise.all(records.map(record =>
-      limit(async () => ({ ...record, ...await additionalAttributes(record) }))
+    return (records: R[]) => Promise.all(records.map(async record => {
+      const populatedRecord: any = {...record}
+      for (const [key, mapper] of Object.entries(additionalAttributes)) {
+        populatedRecord[key] = await limit(() => mapper(record, {rows: records, req}))
+      }
+
+      return populatedRecord
+    }
     ))
   }

src/index.ts

@@ -5,6 +5,7 @@ import { getOne } from './getOne'
 import { create, Create } from './create'
 import { update, Update } from './update'
 import { destroy, Destroy } from './delete'
+import { populateReference, populateReferenceMany, populateReferenceManyCount, populateReferenceOne } from './additionalAttributeHelpers'
 
 export interface Actions<I extends string | number, R> {
   get: Get<R> | null
@@ -14,8 +15,7 @@ export interface Actions<I extends string | number, R> {
 }
 
 
-
-export { Create, Destroy, Update, Get }
+export { Create, Destroy, Update, Get, populateReference, populateReferenceMany, populateReferenceManyCount, populateReferenceOne }
 
 export const crud = <I extends string | number, R>(
   path: string,

tests/index.spec.ts

@@ -1,5 +1,5 @@
 import { Server } from 'http'
-import { crud } from '../src'
+import { crud, populateReferenceMany, populateReferenceManyCount } from '../src'
 import { setupApp } from './app'
 
 describe('crud', () => {
@@ -62,8 +62,8 @@ describe('crud', () => {
           crud<number, { id: number }>('/users', {
             get: jest.fn().mockResolvedValue({ rows: [{ id: 1 }], count: 1 }),
           }, {
-            additionalAttributes: async (record) => {
-              return { additionalProperty: await new Promise(resolve => resolve(`value ${record.id}`)) }
+            additionalAttributes:  {
+additionalProperty: async (record) => new Promise(resolve => resolve(`value ${record.id}`))
             }
           }),
           ctx
@@ -76,6 +76,73 @@ describe('crud', () => {
         })
         expect(response.data[0]).toEqual({ id: 1, additionalProperty: 'value 1' })
       })
+
+      describe('populateReferenceMany', () => {
+        it('populate references', async () => {
+          const dataProvider = await setupApp(
+            crud<number, { id: number }>('/users', {
+              get: jest.fn().mockResolvedValue({ rows: [{ id: 1 }, { id: 2 } , { id: 3 }], count: 2 }),
+            }, {
+              additionalAttributes: {
+                posts: populateReferenceMany({
+                  fetchAll: async () => [
+                    {id: 10, authorId: 1},
+                    {id: 11, authorId: 1},
+                    {id: 12, authorId: 2},
+                  ],
+                  target: 'authorId'
+                })
+              }
+            }),
+            ctx
+          )
+
+          const response = await dataProvider.getList('users', {
+            pagination: { page: 0, perPage: 25 },
+            sort: { field: 'id', order: 'DESC' },
+            filter: {},
+          })
+          expect(response.data[0]).toEqual({ id: 1, posts: [
+            {id: 10, authorId: 1},
+                    {id: 11, authorId: 1}
+          ] })
+          expect(response.data[1]).toEqual({ id: 2, posts: [
+            {id: 12, authorId: 2},
+          ] })
+          expect(response.data[2]).toEqual({ id: 3, posts: [] })
+        })
+      })
+
+      describe('populateReferenceManyCount', () => {
+        it('populate reference counts', async () => {
+          const dataProvider = await setupApp(
+            crud<number, { id: number }>('/users', {
+              get: jest.fn().mockResolvedValue({ rows: [{ id: 1 }, { id: 2 } , { id: 3 }], count: 2 }),
+            }, {
+              additionalAttributes: {
+                postsCount: populateReferenceManyCount({
+                  fetchAll: async () => [
+                    {id: 10, authorId: 1},
+                    {id: 11, authorId: 1},
+                    {id: 12, authorId: 2},
+                  ],
+                  target: 'authorId'
+                })
+              }
+            }),
+            ctx
+          )
+
+          const response = await dataProvider.getList('users', {
+            pagination: { page: 0, perPage: 25 },
+            sort: { field: 'id', order: 'DESC' },
+            filter: {},
+          })
+          expect(response.data[0]).toEqual({ id: 1, postsCount: 2 })
+          expect(response.data[1]).toEqual({ id: 2, postsCount: 1 })
+          expect(response.data[2]).toEqual({ id: 3, postsCount: 0 })
+        })
+      })
     })
 
     describe('DELETE', () => {

yarn.lock

@@ -5304,13 +5304,6 @@ p-is-promise@^3.0.0:
   resolved "https://registry.yarnpkg.com/p-is-promise/-/p-is-promise-3.0.0.tgz#58e78c7dfe2e163cf2a04ff869e7c1dba64a5971"
   integrity sha512-Wo8VsW4IRQSKVXsJCn7TomUaVtyfjVDn3nUP7kE967BQk0CwFpdbZs0X0uk5sW9mkBa9eNM7hCMaG93WUAwxYQ==
 
-p-limit@3:
-  version "3.1.0"
-  resolved "https://registry.yarnpkg.com/p-limit/-/p-limit-3.1.0.tgz#e1daccbe78d0d1388ca18c64fea38e3e57e3706b"
-  integrity sha512-TYOanM3wGwNGsZN2cVTYPArw454xnXj5qmWF1bEoAc4+cU/ol7GVh7odevjp1FNHduHc3KZMcFduxU5Xc6uJRQ==
-  dependencies:
-    yocto-queue "^0.1.0"
-
 p-limit@^1.1.0:
   version "1.3.0"
   resolved "https://registry.yarnpkg.com/p-limit/-/p-limit-1.3.0.tgz#b86bd5f0c25690911c7590fcbfc2010d54b3ccb8"
@@ -6932,8 +6925,3 @@ yargs@^16.2.0:
     string-width "^4.2.0"
     y18n "^5.0.5"
     yargs-parser "^20.2.2"
-
-yocto-queue@^0.1.0:
-  version "0.1.0"
-  resolved "https://registry.yarnpkg.com/yocto-queue/-/yocto-queue-0.1.0.tgz#0294eb3dee05028d31ee1a5fa2c556a6aaf10a1b"
-  integrity sha512-rVksvsnNCdJ/ohGc6xgPwyN8eheCxsiLM8mxuE/t/mOVqJewPuO1miLpTHQiRgTKCLexL4MeAFVagts7HmNZ2Q==