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 import { forceNumber } from '@shared/core-utils'
   7
   8 type ActivityPubCollectionPaginationHandler = (start: number, count: number) => Bluebird<ResultList<any>> | Promise<ResultList<any>>
   9
  10 async function activityPubCollectionPagination (
  11   baseUrl: string,
  12   handler: ActivityPubCollectionPaginationHandler,
  13   page?: any,
  14   size = ACTIVITY_PUB.COLLECTION_ITEMS_PER_PAGE
  15 ) {
  16   if (!page || !validator.isInt(page)) {
  17     // We just display the first page URL, we only need the total items
  18     const result = await handler(0, 1)
  19
  20     return {
  21       id: baseUrl,
  22       type: 'OrderedCollection',
  23       totalItems: result.total,
  24       first: result.data.length === 0
  25         ? undefined
  26         : baseUrl + '?page=1'
  27     }
  28   }
  29
  30   const { start, count } = pageToStartAndCount(page, size)
  31   const result = await handler(start, count)
  32
  33   let next: string | undefined
  34   let prev: string | undefined
  35
  36   // Assert page is a number
  37   page = forceNumber(page)
  38
  39   // There are more results
  40   if (result.total > page * size) {
  41     next = baseUrl + '?page=' + (page + 1)
  42   }
  43
  44   if (page > 1) {
  45     prev = baseUrl + '?page=' + (page - 1)
  46   }
  47
  48   return {
  49     id: baseUrl + '?page=' + page,
  50     type: 'OrderedCollectionPage',
  51     prev,
  52     next,
  53     partOf: baseUrl,
  54     orderedItems: result.data,
  55     totalItems: result.total
  56   }
  57 }
  58
  59 // ---------------------------------------------------------------------------
  60
  61 export {
  62   activityPubCollectionPagination
  63 }