meses-feed/src/classes/PreviousFeedActivityQuery.js

Meses feed SDK in JavaScript

class PreviousFeedActivityQuery {
  constructor(service, feedName, startActivityId) {
    this._service = service
    this._feedName = feedName
    this._next = startActivityId
    this._reachEnd = false
  }

  /**
   * Load some feed activities ordered by activity timestamp
   * 
   * @param  {Number} items - number of items to load
   * @return {Promise} array of feed activities if fulfilled.
   */
  load(items) {
    if (this._reachEnd)
      return new Promise(function(resolve, reject) { resolve([]) })

    const service = this._service
    const feedName = this._feedName
    const next = this._next

    return new Promise(function(resolve, reject) {
      service.getFeedActivities(feedName, next, items)
        .then(result => { 
          if (result.nextActivityId == null)
            this._reachEnd = true
          
          this._next = result.nextActivityId
          resolve(result.feedActivities) 
        })
        .catch(err => reject(err))
    }.bind(this))
  }

  /**
   * Predicate for checking whether the query can load more conversation
   * 
   * @return {Boolean} TRUE if query can load more conversation
   */
  hasMore() { return !this._reachEnd }
}

export default PreviousFeedActivityQuery