add PR deploy previews, and cleanup using force_orphan when production builds

Author: trevorcampbell

.github/workflows/build_book.yml

@@ -30,7 +30,6 @@ jobs:
           github_token: ${{ secrets.GITHUB_TOKEN }}
           publish_dir: source/_build/html
           cname: python.datasciencebook.ca
-          keep_files: true
-          # force_orphan: true # once peaceiris updates to v4, change this to true and keep_files: true for the PR / main branch deploy previews
+          force_orphan: true # this will clean up all previous PR previews / main branch preview
 
 

.github/workflows/deploy_pr_preview.yml

@@ -0,0 +1,36 @@
+name: "Rebuild and deploy PR version of book to gh-pages branch in pull###/ folder"
+on:
+  pull_request:
+    types: [reopened, opened, synchronize]
+    paths:
+      - source/**
+jobs:
+  deploy-book:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+      packages: write
+
+    steps:
+      - name: checkout
+        uses: actions/checkout@v2
+        with:
+          fetch-depth: '0'
+          ref: ${{ github.head_ref }}
+          
+      - name: Build the book
+        run: |
+          ./build_html.sh
+
+       # Push the book's HTML to github-pages
+      - name: GitHub Pages action
+        uses: peaceiris/[email protected]
+        with:
+          github_token: ${{ secrets.GITHUB_TOKEN }}
+          publish_dir: source/_build/html
+          keep_files: true
+          destination_dir: pull${{ github.event.number }}
+          # force_orphan: true # once peaceiris updates to v4, change this to true and keep_files: true for the PR / main branch deploy previews
+
+
+