Add Open Graph protocol meta tags to Maniphest task pages

Summary:
Add OGP <meta> tags to Maniphest task pages when the task is publicly accessible and anonymously accessed. See https://ogp.me/

Based on rP2c72c2b924ffa3f8a49dbec636a2cdca3bae004f reverted in rP49b57eae7df52c189aef1d973823c697fc97fd4b.

Closes T15472

Test Plan:
* Use the default Phorge logo, open a Maniphest task, look at the headers in its HTML.
* Set a custom Phorge logo via `config/edit/ui.logo/`.
* Access a task with "View Policy: All Users" while logged in: No OGP headers included.
* Access a task with "View Policy: Public" while logged in: No OGP headers included.
* Access a task with "View Policy: All Users" while logged out: No OGP headers included; "Access Denied: Restricted Maniphest Task" displayed.
* Access a task with "View Policy: Public" while logged out: OGP headers included.
* Access a task with "View Policy: Public" while logged out with a task description and a task without a task description: OGP headers included.

Reviewers: O1 Blessed Committers, valerio.bozzolan

Reviewed By: O1 Blessed Committers, valerio.bozzolan

Subscribers: avivey, tobiaswiese, valerio.bozzolan, Matthew, Cigaryno

Maniphest Tasks: T15472

Differential Revision: https://we.phorge.it/D25668

src/applications/config/custom/PhabricatorCustomLogoConfigType.php

@@ -13,6 +13,45 @@ final class PhabricatorCustomLogoConfigType
     return idx($logo, 'wordmarkText');
   }
 
+  /**
+   * Return the full URI of the Phorge logo
+   * @param PhabricatorUser Current viewer
+   * @return string Full URI of the Phorge logo
+   */
+  public static function getLogoURI(PhabricatorUser $viewer) {
+    $logo_uri = null;
+
+    $custom_header = self::getLogoImagePHID();
+    if ($custom_header) {
+      $cache = PhabricatorCaches::getImmutableCache();
+      $cache_key_logo = 'ui.custom-header.logo-phid.v3.'.$custom_header;
+      $logo_uri = $cache->getKey($cache_key_logo);
+
+      if (!$logo_uri) {
+        // NOTE: If the file policy has been changed to be restrictive, we'll
+        // miss here and just show the default logo. The cache will fill later
+        // when someone who can see the file loads the page. This might be a
+        // little spooky, see T11982.
+        $files = id(new PhabricatorFileQuery())
+          ->setViewer($viewer)
+          ->withPHIDs(array($custom_header))
+          ->execute();
+        $file = head($files);
+        if ($file) {
+          $logo_uri = $file->getViewURI();
+          $cache->setKey($cache_key_logo, $logo_uri);
+        }
+      }
+    }
+
+    if (!$logo_uri) {
+      $logo_uri =
+        celerity_get_resource_uri('/rsrc/image/logo/project-logo.png');
+    }
+
+    return $logo_uri;
+  }
+
   public function validateOption(PhabricatorConfigOption $option, $value) {
     if (!is_array($value)) {
       throw new Exception(

src/applications/maniphest/controller/ManiphestTaskDetailController.php

@@ -203,8 +203,7 @@ final class ManiphestTaskDetailController extends ManiphestController {
       ->addPropertySection(pht('Description'), $description)
       ->addPropertySection(pht('Details'), $details);
 
-
-    return $this->newPage()
+    $page = $this->newPage()
       ->setTitle($title)
       ->setCrumbs($crumbs)
       ->setPageObjectPHIDs(
@@ -213,6 +212,74 @@ final class ManiphestTaskDetailController extends ManiphestController {
         ))
       ->appendChild($view);
 
+    if ($this->getIncludeOpenGraphMetadata($viewer, $task)) {
+      $page = $this->addOpenGraphProtocolMetadataTags($page, $task);
+    }
+
+    return $page;
+  }
+
+  /**
+   * Whether the page should include Open Graph metadata tags
+   * @param PhabricatorUser $viewer Viewer of the object
+   * @param object $object
+   * @return bool True if the page should serve Open Graph metadata tags
+   */
+  private function getIncludeOpenGraphMetadata(PhabricatorUser $viewer,
+    $object) {
+    // Don't waste time adding OpenGraph metadata for logged-in users
+    if ($viewer->getIsStandardUser()) {
+      return false;
+    }
+    // Include OpenGraph tags only for public objects
+    return $object->getViewPolicy() === PhabricatorPolicies::POLICY_PUBLIC;
+  }
+
+  /**
+   * Get Open Graph Protocol metadata values
+   * @param ManiphestTask $task
+   * @return array Map of Open Graph property => value
+   */
+  private function getOpenGraphProtocolMetadataValues($task) {
+    $viewer = $this->getViewer();
+
+    $v = [];
+    $v['og:site_name'] = PlatformSymbols::getPlatformServerName();
+    $v['og:type'] = 'object';
+    $v['og:url'] = PhabricatorEnv::getProductionURI($task->getURI());
+    $v['og:title'] = $task->getMonogram().' '.$task->getTitle();
+
+    $desc = $task->getDescription();
+    if (phutil_nonempty_string($desc)) {
+      $v['og:description'] =
+        PhabricatorMarkupEngine::summarizeSentence($desc);
+    }
+
+    $v['og:image'] =
+      PhabricatorCustomLogoConfigType::getLogoURI($viewer);
+
+    $v['og:image:height'] = 64;
+    $v['og:image:width'] = 64;
+
+    return $v;
+  }
+
+  /**
+   * Add Open Graph Protocol metadata tags to Maniphest task page
+   * @param PhabricatorStandardPageView $page
+   * @param ManiphestTask $task
+   * @return $page with additional OGP <meta> tags
+   */
+  private function addOpenGraphProtocolMetadataTags($page, $task) {
+    foreach ($this->getOpenGraphProtocolMetadataValues($task) as $k => $v) {
+      $page->addHeadItem(phutil_tag(
+        'meta',
+        array(
+          'property' => $k,
+          'content' => $v,
+        )));
+    }
+    return $page;
   }
 
   private function buildHeaderView(ManiphestTask $task) {

src/view/page/PhabricatorStandardPageView.php

@@ -378,7 +378,6 @@ final class PhabricatorStandardPageView extends PhabricatorBarePageView
 
   /**
    * Insert a HTML element into <head> of the page to render.
-   * Used by PhameBlogViewController.
    *
    * @param PhutilSafeHTML HTML header to add
    */

src/view/page/menu/PhabricatorMainMenuView.php

@@ -293,35 +293,14 @@ final class PhabricatorMainMenuView extends AphrontView {
   }
 
   private function renderPhabricatorLogo() {
-    $custom_header = PhabricatorCustomLogoConfigType::getLogoImagePHID();
-
     $logo_style = array();
+    $custom_header = PhabricatorCustomLogoConfigType::getLogoImagePHID();
     if ($custom_header) {
-      $cache = PhabricatorCaches::getImmutableCache();
-      $cache_key_logo = 'ui.custom-header.logo-phid.v3.'.$custom_header;
-
-      $logo_uri = $cache->getKey($cache_key_logo);
-      if (!$logo_uri) {
-        // NOTE: If the file policy has been changed to be restrictive, we'll
-        // miss here and just show the default logo. The cache will fill later
-        // when someone who can see the file loads the page. This might be a
-        // little spooky, see T11982.
-        $files = id(new PhabricatorFileQuery())
-          ->setViewer($this->getViewer())
-          ->withPHIDs(array($custom_header))
-          ->execute();
-        $file = head($files);
-        if ($file) {
-          $logo_uri = $file->getViewURI();
-          $cache->setKey($cache_key_logo, $logo_uri);
-        }
-      }
-
-      if ($logo_uri) {
-        $logo_style[] = 'background-size: 40px 40px;';
-        $logo_style[] = 'background-position: 0 0;';
-        $logo_style[] = 'background-image: url('.$logo_uri.')';
-      }
+      $viewer = $this->getViewer();
+      $logo_uri = PhabricatorCustomLogoConfigType::getLogoURI($viewer);
+      $logo_style[] = 'background-size: 40px 40px;';
+      $logo_style[] = 'background-position: 0 0;';
+      $logo_style[] = 'background-image: url('.$logo_uri.')';
     }
 
     $logo_node = phutil_tag(
@@ -331,7 +310,6 @@ final class PhabricatorMainMenuView extends AphrontView {
         'style' => implode(' ', $logo_style),
       ));
 
-
     $wordmark_text = PhabricatorCustomLogoConfigType::getLogoWordmark();
     if (!phutil_nonempty_string($wordmark_text)) {
       $wordmark_text = PlatformSymbols::getPlatformServerName();