conditional_convert_via_pandoc.yml

name: conditional_convert_via_pandoc
#
# A script to check for changed and added .md files in content/ and convert those with pandoc (except for _index.md)
#
# Thanks to Gérald Barré aka. meziantou for the basic template of the condition check
# Written by Marcel Kaiser
#
# published: 2024-10-29
# last edit: 2024-11-16
#
on:
  push:
    branches:
      - 'main' # Do the work exclusively for the branch deploying the website

jobs:
  # Seperate jobs to be able to possibly use condition_check_files for other tasks as well
  condition_check_files:
    runs-on: 'ubuntu-22.04'
    outputs:
      bool_files_changed: ${{ steps.check_file_changed.outputs.bool_files_changed }}
      list_changed_files: ${{ steps.check_file_changed.outputs.list_changed_files }}
    steps:
    - uses: actions/checkout@v4
      with:
        fetch-depth: 2
    - shell: pwsh
      id: check_file_changed
      run: |
        # Look only for changed files (A - added, M - modified) and return their path+name (the specific changes are irrelevant)
        $diff=git diff --name-only --diff-filter=AM "HEAD^" HEAD

        # Filter the files under content/ with the .md extension excluding the Hugo associated _index.md files
        $FilesDiff=$diff | Where-Object { $_ -match 'content/' -and $_ -match '.md$' -and -not ($_ -match '_index.md') }
        $HasDiff=$FilesDiff.Length -gt 0

        # Set the output named "bool_files_changed"
        echo "bool_files_changed=$HasDiff" >> $env:GITHUB_OUTPUT
        echo "list_changed_files=$FilesDiff" >> $env:GITHUB_OUTPUT

  # Run the job only with 'bool_files_changed' equals 'True'
  conditional_pandoc:
    runs-on: 'ubuntu-22.04'
    container:
      image: pandoc/latex:3.5
    needs: [ condition_check_files ]
    if: needs.condition_check_files.outputs.bool_files_changed == 'true'
    env:
      list_changed_files: ${{ needs.condition_check_files.outputs.list_changed_files }}
    steps:
      - uses: actions/checkout@v4  # In order to find the script pandoc.sh
        with:
          fetch-depth: 2
      - name: Run Pandoc in Docker
        # This is a one-liner. It gets a Docker Image of pandoc/latex:3.5 working directly in the workspace (because
        # $list_changed_files contains relative paths) and executes the script.
        run: ./pandoc.sh ${{ env.list_changed_files }}
      - name: Commit files # transfer the new files into the repository
        run: |
          git config --local user.name "GH_Action_Bot"
          git add ./content
          git commit -m "GH Action: Pandoc | New output for changed files"
          git push -f origin main