Find Jenkins Build cause

Jenkinsfile

#!/usr/bin/env groovy

import hudson.model.*
import hudson.EnvVars
import groovy.json.JsonSlurperClassic
import groovy.json.JsonBuilder
import groovy.json.JsonOutput
import java.net.URL


pipeline {
  agent any
  stages {
    stage('Check Build Cause'){
      steps{
        script{
          // get Build Causes
          // https://stackoverflow.com/questions/43597803/how-to-differentiate-build-triggers-in-jenkins-pipeline
          
          echo "${currentBuild.getBuildCauses()}" //Always returns full Cause
          echo "${currentBuild.getBuildCauses('jenkins.branch.BranchEventCause')}" // Only returns for branch events
          echo "${currentBuild.getBuildCauses('hudson.triggers.SCMTrigger$SCMTriggerCause')}" // Only returns SCM Trigger
          echo "${currentBuild.getBuildCauses('hudson.model.Cause$UserIdCause')}"  // Only returns if user initiates via Jenkins GUI
          
          def GitPushCause = currentBuild.getBuildCauses('jenkins.branch.BranchEventCause')
          def UserCause = currentBuild.getBuildCauses('hudson.model.Cause$UserIdCause')
          
          // If a cause was populated do... 
          if (GitPushCause) {
            
              println "********* Git Push *********"
              println GitPushCause.getShortDescription()
              stage ('Stage 1') {
                  sh 'echo Stage 1'
              }
            
          }  else if (UserCause) {

              println "******* Manual Build Detected *******"
              println UserCause.getShortDescription()
              stage ('Stage 2') {
                  sh 'echo Stage 2'
              }
          }else {
              println "unknown cause"
          }
        }
      }
    }
  }
}