add preview workflow

preview.yml

@@ -0,0 +1,74 @@
+# This file generated from a template file maintained in the ivoatex repository.
+# To create and install it into a project repository, do:
+#    make github-preview
+#    git commit
+#    git push
+#
+name: Update PDF Preview
+
+env:
+  doc_name   : ObsCoreExtensionForRadioData
+  branch_name: ${{ github.head_ref || github.ref_name }}
+  tag_preview: auto-pdf-preview
+
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+
+    - name: Checkout the repository
+      uses: actions/checkout@v4
+      with:
+        submodules: true
+
+    - name: Setup dependencies
+      run: |
+        sudo apt update
+        sudo apt install texlive-latex-base texlive-latex-recommended \
+                         texlive-latex-extra texlive-fonts-recommended \
+                         librsvg2-bin latexmk \
+                         pdftk xsltproc latexmk cm-super
+
+    - name: Build the document
+      run: make ${{ env.doc_name }}-draft.pdf
+
+    - name: Check the output
+      run: |
+        test -f ${{ env.doc_name }}-draft.pdf
+        test -f ${{ env.doc_name }}.bbl
+
+    - name: Remove the former PDF preview (if any)
+      run: |
+        existingTag=$( gh release list --exclude-drafts --json 'isPrerelease,tagName' \
+                                       --jq '.[] | select(.isPrerelease == true and .tagName == "${{ env.tag_preview }}") | .tagName' \
+                                       | xargs -n 1 echo )
+        if [ -n "$existingTag" ];
+        then
+          gh release delete --cleanup-tag "$existingTag"
+        fi
+      env:
+        GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+    - name: Upload the new PDF preview
+      run: |
+        RELEASE_NOTES="This release aims to provide a PDF preview of the last commit applied on this repository.
+          It will be updated automatically after each merge of a PullRequest.
+          **DO NOT PUBLISH THIS PRE-RELEASE!**
+          _Corresponding commit: ${{ github.sha }}_"
+
+        gh release create ${{ env.tag_preview }} \
+                          ${{ env.doc_name }}-draft.pdf \
+                          --prerelease \
+                          --target "${{ env.branch_name }}" \
+                          --title 'Auto PDF Preview' \
+                          --notes "$RELEASE_NOTES"
+      env:
+        GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+