Fix conflicting dokka config, downgrade Gradle for Dokka, and add Git…

…hubPages (#2942)

.github/workflows/generate-alpha-tag.yaml

@@ -2,6 +2,8 @@ name: generate-alpha-tag
 
 on:
   push:
+    paths-ignore:
+      - 'docs/**'
     branches:
       - main
 

.github/workflows/githubpages.yaml

@@ -0,0 +1,27 @@
+name: githubpages
+
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+  githubpages:
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+
+    steps:
+      - uses: actions/checkout@v3
+        with:
+          fetch-depth: 0
+          token: ${{ secrets.TOKEN_GITHUB_ACTION }}
+
+      - name: Dokka
+        id: Dokka
+        run: ./gradlew cleanDocs dokkaHtmlMultiModule -Pgithubpages=true
+
+      - name: Push
+        run: |
+          git add .
+          git commit -m "Update github pages"
+          git push

.github/workflows/publish-landing-page.yaml

@@ -2,6 +2,8 @@ name: Publish landing page
 
 on:
   push:
+    paths-ignore:
+      - 'docs/**'
     branches:
       - main
     paths:

build.gradle.kts

@@ -118,17 +118,20 @@ tasks {
   getByName("knitPrepare").dependsOn(getTasksByName("dokka", true))
 
   withType<DokkaMultiModuleTask>().configureEach {
-    outputDirectory.set(rootDir.resolve("arrow-site/docs/apidocs"))
+    outputDirectory.set(docFolder())
     moduleName.set("Arrow")
   }
 
   register<Delete>("cleanDocs") {
-    val folder = rootDir.resolve("arrow-site/docs/apidocs")
+    val folder = docFolder()
     val content = folder.listFiles()?.filter { it != folder }
     delete(content)
   }
 }
 
+fun docFolder(): File =
+  project.properties["githubpages"]?.let { file("docs").also { it.mkdir() } } ?: rootDir.resolve("arrow-site/docs/apidocs")
+
 apiValidation {
   val ignoreApiValidation = if (!enableCompatibilityMetadataVariant) {
     listOf("arrow-optics-ksp-plugin", "arrow-site")

gradle.properties

@@ -35,3 +35,5 @@ ROOT_PROJECT=../gradle/main.gradle
 TEST_COVERAGE=../../gradle/test-coverage.gradle
 ANIMALSNIFFER=../../gradle/animalsniffer.gradle
 ANIMALSNIFFER_MPP=../../gradle/animalsniffer-mpp.gradle
+
+dokkaEnabled=false

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,6 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.0.1-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-7.6-bin.zip
 networkTimeout=10000
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists