server/lib/activitypub/collection.ts

   1 import Bluebird from 'bluebird'
   2 import validator from 'validator'
   3 import { pageToStartAndCount } from '@server/helpers/core-utils'
   4 import { ACTIVITY_PUB } from '@server/initializers/constants'
   5 import { ResultList } from '@shared/models'
   6
   7 type ActivityPubCollectionPaginationHandler = (start: number, count: number) => Bluebird<ResultList<any>> | Promise<ResultList<any>>
   8
   9 async function activityPubCollectionPagination (
  10   baseUrl: string,
  11   handler: ActivityPubCollectionPaginationHandler,
  12   page?: any,
  13   size = ACTIVITY_PUB.COLLECTION_ITEMS_PER_PAGE
  14 ) {
  15   if (!page || !validator.isInt(page)) {
  16     // We just display the first page URL, we only need the total items
  17     const result = await handler(0, 1)
  18
  19     return {
  20       id: baseUrl,
  21       type: 'OrderedCollection',
  22       totalItems: result.total,
  23       first: result.data.length === 0
  24         ? undefined
  25         : baseUrl + '?page=1'
  26     }
  27   }
  28
  29   const { start, count } = pageToStartAndCount(page, size)
  30   const result = await handler(start, count)
  31
  32   let next: string | undefined
  33   let prev: string | undefined
  34
  35   // Assert page is a number
  36   page = parseInt(page, 10)
  37
  38   // There are more results
  39   if (result.total > page * size) {
  40     next = baseUrl + '?page=' + (page + 1)
  41   }
  42
  43   if (page > 1) {
  44     prev = baseUrl + '?page=' + (page - 1)
  45   }
  46
  47   return {
  48     id: baseUrl + '?page=' + page,
  49     type: 'OrderedCollectionPage',
  50     prev,
  51     next,
  52     partOf: baseUrl,
  53     orderedItems: result.data,
  54     totalItems: result.total
  55   }
  56 }
  57
  58 // ---------------------------------------------------------------------------
  59
  60 export {
  61   activityPubCollectionPagination
  62 }