def changedFilesList = []
def forcedBuild = false
def allProjects = ['Project1', 'Project2', 'Project3', 'Project4', 'Project5']

pipeline {
  agent {
    node {
      label 'WindowsBuildBox'
    }
  }
  stages {
    stage('DetectChanges') {
      steps {
        git(url: '<myrepo.git>', branch: env.BRANCH_NAME, changelog: true, credentialsId: '<mycredentials>')
        script {
          def changeLogSets = currentBuild.changeSets
          for (int i = 0; i < changeLogSets.size(); i++) {
            def entries = changeLogSets[i].items
            for (int j = 0; j < entries.length; j++) {
              def entry = entries[j]
              echo "${entry.commitId} by ${entry.author} on ${new Date(entry.timestamp)}: ${entry.msg}"
              def files = new ArrayList(entry.affectedFiles)
              for (int k = 0; k < files.size(); k++) {
                def file = files[k]
                echo "  ${file.editType.name} ${file.path}"
                changedFilesList.add("${file.path}")
              }
            }
          }
          if (changedFilesList.isEmpty()) {
            echo "No files were changed"
            forcedBuild = true
          }else{
            echo "changed files: $changedFilesList"
          }
        }
      }
    }

    stage('Build Trigger') {
      steps {
        echo "${allProjects}"
        buildProject(allProjects as String[], forcedBuild, changedFilesList as String[])
      }
    }
  }
}
  void buildProject(String[] allProjects, boolean forcedBuild, String[] changedFilesList) {
    allProjects.each { project ->
      script {
        stage(project) {
          when {
            expression { forcedBuild || changedFilesList.join(", ").contains("${project}") }
          }
          dir("${project}") {
            bat("echo building: ${project}")
          }
        }
      }
    }
  }