title: @Selector and notify
body: <p>I have a grails project using react js. Below is fraction of code in the beginning of a function in one of groovy file</p>
  
  <pre><code>@Selector('update.intrans.info')
      def updateIntransInfoForLot(String lotNumber) {
          log.info "updateIntransInfoForLot: $lotNumber"
          def lot = Lot.findByAlotNumber(lotNumber)
  ...................//some code here
  lot.save(flush:true)
  </code></pre>
  
  <p>I was trying to find this updateIntransInfoForLot elsewhere in the project but couldn't find. So I tried to search by </p>
  
  <blockquote>
    <p>update.intrans.info</p>
  </blockquote>
  
  <p>and I found below at another groovy file.</p>
  
  <pre><code>notify 'update.intrans.info', lot.alotNumber
  result = [type: 'lot', function: 'releaseIntransLot', arguments: [mapFields(lot)]]
  </code></pre>
  
  <p>May I know what are this @Selector and notify? How they are linked together and what is going on in this code? It will be helpful if anyone could give me a brief with website link to appropriate documentation that I can further read on this.</p>