meses-messaging/src/classes/NewMessageUpdateHandler.js

Meses messaging SDK in JavaScript

class NewMessageUpdateHandler {
  constructor(service, activeConversationName, identifier, callback, timeout) {
    this._service = service
    this._activeConversationName = activeConversationName
    this._identifier = identifier
    this._callback = callback
    this._timeout = timeout ? timeout : 3000
    this._lastCheckTime = new Date().getTime()
    this._intervalId = null
  }

  /**
   * Stop checking for update
   * 
   * @return {Void}
   */
  destroy() { clearInterval(this._intervalId) }

  activate() {
    const checkNewMessage = this.checkNewMessage.bind(this)
    const callback = this._callback
    const timeout = this._timeout

    this._intervalId = setInterval(function() {
      checkNewMessage()
        .then(result => callback(null, result))
        .catch(err => callback(err, null))  
    }, timeout)
  }

  /**
   * Method for retrieving new messages
   * 
   * @return {Promise} array of messages if fulfilled.
   */
  checkNewMessage() {
    const service = this._service
    const activeConversationName = this._activeConversationName
    const lastCheckTime = this._lastCheckTime
    const now = new Date().getTime()

    return new Promise(function(resolve, reject) {
      service.getMessagesByInterval(activeConversationName, lastCheckTime, now)
        .then(function(result) { this._lastCheckTime = now + 1; resolve(result) }.bind(this))
        .catch(err => reject(err))
    }.bind(this))
  }
}

export default NewMessageUpdateHandler