Provide better strings in policy errors and exceptions

Summary:
Ref T603. This could probably use a little more polish, but improve the quality of policy error messages.

  - Provide as much detail as possible.
  - Fix all the strings for i18n.
  - Explain special rules to the user.
  - Allow indirect policy filters to raise policy exceptions instead of 404s.

Test Plan: See screenshots.

Reviewers: btrahan, chad

Reviewed By: chad

CC: aran

Maniphest Tasks: T603

Differential Revision: https://secure.phabricator.com/D7151

src/aphront/configuration/AphrontDefaultApplicationConfiguration.php

@@ -164,9 +164,23 @@ class AphrontDefaultApplicationConfiguration
         return $login_controller->processRequest();
       }
 
-      $content = hsprintf(
-        '<div class="aphront-policy-exception">%s</div>',
-        $ex->getMessage());
+      $list = $ex->getMoreInfo();
+      foreach ($list as $key => $item) {
+        $list[$key] = phutil_tag('li', array(), $item);
+      }
+      if ($list) {
+        $list = phutil_tag('ul', array(), $list);
+      }
+
+      $content = phutil_tag(
+        'div',
+        array(
+          'class' => 'aphront-policy-exception',
+        ),
+        array(
+          $ex->getMessage(),
+          $list,
+        ));
 
       $dialog = new AphrontDialogView();
       $dialog

src/applications/differential/query/DifferentialRevisionQuery.php

@@ -416,9 +416,13 @@ final class DifferentialRevisionQuery
       // The revision has an associated repository, and the viewer can't see
       // it, and the viewer has no special capabilities. Filter out this
       // revision.
+      $this->didRejectResult($revision);
       unset($revisions[$key]);
     }
 
+    if (!$revisions) {
+      return array();
+    }
 
     $table = new DifferentialRevision();
     $conn_r = $table->establishConnection('r');

src/applications/differential/storage/DifferentialRevision.php

@@ -338,7 +338,7 @@ final class DifferentialRevision extends DifferentialDAO
       case PhabricatorPolicyCapability::CAN_VIEW:
         $description[] = pht(
           "A revision's reviewers can always view it.");
-        if ($this->getRepository()) {
+        if ($this->getRepositoryPHID()) {
           $description[] = pht(
             'This revision belongs to a repository. Other users must be able '.
             'to view the repository in order to view this revision.');

src/applications/policy/exception/PhabricatorPolicyException.php

@@ -2,4 +2,15 @@
 
 final class PhabricatorPolicyException extends Exception {
 
+  private $moreInfo = array();
+
+  public function setMoreInfo(array $more_info) {
+    $this->moreInfo = $more_info;
+    return $this;
+  }
+
+  public function getMoreInfo() {
+    return $this->moreInfo;
+  }
+
 }

src/applications/policy/filter/PhabricatorPolicyFilter.php

@@ -248,28 +248,64 @@ final class PhabricatorPolicyFilter {
       "This object has an impossible {$verb} policy.");
   }
 
-  private function rejectObject($object, $policy, $capability) {
+  public function rejectObject(
+    PhabricatorPolicyInterface $object,
+    $policy,
+    $capability) {
+
     if (!$this->raisePolicyExceptions) {
       return;
     }
 
-    // TODO: clean this up
-    $verb = $capability;
-
-    $message = "You do not have permission to {$verb} this object.";
+    $more = array();
+    switch ($capability) {
+      case PhabricatorPolicyCapability::CAN_VIEW:
+        $message = pht(
+          'This object exists, but you do not have permission to view it.');
+        break;
+      case PhabricatorPolicyCapability::CAN_EDIT:
+        $message = pht('You do not have permission to edit this object.');
+        break;
+      case PhabricatorPolicyCapability::CAN_JOIN:
+        $message = pht('You do not have permission to join this object.');
+        break;
+    }
 
     switch ($policy) {
       case PhabricatorPolicies::POLICY_PUBLIC:
-        $who = "This is curious, since anyone can {$verb} the object.";
+        // Presumably, this is a bug, so we don't bother specializing the
+        // strings.
+        $more = pht('This object is public.');
         break;
       case PhabricatorPolicies::POLICY_USER:
-        $who = "To {$verb} this object, you must be logged in.";
+        // We always raise this as "log in", so we don't need to specialize.
+        $more = pht('This object is available to logged in users.');
         break;
       case PhabricatorPolicies::POLICY_ADMIN:
-        $who = "To {$verb} this object, you must be an administrator.";
+        switch ($capability) {
+          case PhabricatorPolicyCapability::CAN_VIEW:
+            $more = pht('Administrators can view this object.');
+            break;
+          case PhabricatorPolicyCapability::CAN_EDIT:
+            $more = pht('Administrators can edit this object.');
+            break;
+          case PhabricatorPolicyCapability::CAN_JOIN:
+            $more = pht('Administrators can join this object.');
+            break;
+        }
         break;
       case PhabricatorPolicies::POLICY_NOONE:
-        $who = "No one can {$verb} this object.";
+        switch ($capability) {
+          case PhabricatorPolicyCapability::CAN_VIEW:
+            $more = pht('By default, no one can view this object.');
+            break;
+          case PhabricatorPolicyCapability::CAN_EDIT:
+            $more = pht('By default, no one can edit this object.');
+            break;
+          case PhabricatorPolicyCapability::CAN_JOIN:
+            $more = pht('By default, no one can join this object.');
+            break;
+        }
         break;
       default:
         $handle = id(new PhabricatorHandleQuery())
@@ -279,16 +315,55 @@ final class PhabricatorPolicyFilter {
 
         $type = phid_get_type($policy);
         if ($type == PhabricatorProjectPHIDTypeProject::TYPECONST) {
-          $who = "To {$verb} this object, you must be a member of project ".
-                 "'".$handle->getFullName()."'.";
+          switch ($capability) {
+            case PhabricatorPolicyCapability::CAN_VIEW:
+              $more = pht(
+                'This object is visible to members of the project "%s".',
+                $handle->getFullName());
+              break;
+            case PhabricatorPolicyCapability::CAN_EDIT:
+              $more = pht(
+                'This object can be edited by members of the project "%s".',
+                $handle->getFullName());
+              break;
+            case PhabricatorPolicyCapability::CAN_JOIN:
+              $more = pht(
+                'This object can be joined by members of the project "%s".',
+                $handle->getFullName());
+              break;
+          }
         } else if ($type == PhabricatorPeoplePHIDTypeUser::TYPECONST) {
-          $who = "Only '".$handle->getFullName()."' can {$verb} this object.";
+          switch ($capability) {
+            case PhabricatorPolicyCapability::CAN_VIEW:
+              $more = pht(
+                '%s can view this object.',
+                $handle->getFullName());
+              break;
+            case PhabricatorPolicyCapability::CAN_EDIT:
+              $more = pht(
+                '%s can edit this object.',
+                $handle->getFullName());
+              break;
+            case PhabricatorPolicyCapability::CAN_JOIN:
+              $more = pht(
+                '%s can join this object.',
+                $handle->getFullName());
+              break;
+          }
+
         } else {
-          $who = "It is unclear who can {$verb} this object.";
+          $who = pht("This object has an unknown policy setting.");
         }
         break;
     }
 
-    throw new PhabricatorPolicyException("{$message} {$who}");
+    $more = array_merge(
+      array($more),
+      array_filter((array)$object->describeAutomaticCapability($capability)));
+
+    $exception = new PhabricatorPolicyException($message);
+    $exception->setMoreInfo($more);
+
+    throw $exception;
   }
 }

src/infrastructure/query/policy/PhabricatorPolicyAwareQuery.php

@@ -190,18 +190,7 @@ abstract class PhabricatorPolicyAwareQuery extends PhabricatorOffsetPagedQuery {
 
     $results = array();
 
-    $filter = new PhabricatorPolicyFilter();
-    $filter->setViewer($this->viewer);
-
-    if (!$this->capabilities) {
-      $capabilities = array(
-        PhabricatorPolicyCapability::CAN_VIEW,
-      );
-    } else {
-      $capabilities = $this->capabilities;
-    }
-    $filter->requireCapabilities($capabilities);
-    $filter->raisePolicyExceptions($this->shouldRaisePolicyExceptions());
+    $filter = $this->getPolicyFilter();
 
     $offset = (int)$this->getOffset();
     $limit  = (int)$this->getLimit();
@@ -287,6 +276,29 @@ abstract class PhabricatorPolicyAwareQuery extends PhabricatorOffsetPagedQuery {
     return $results;
   }
 
+  private function getPolicyFilter() {
+    $filter = new PhabricatorPolicyFilter();
+    $filter->setViewer($this->viewer);
+    if (!$this->capabilities) {
+      $capabilities = array(
+        PhabricatorPolicyCapability::CAN_VIEW,
+      );
+    } else {
+      $capabilities = $this->capabilities;
+    }
+    $filter->requireCapabilities($capabilities);
+    $filter->raisePolicyExceptions($this->shouldRaisePolicyExceptions());
+
+    return $filter;
+  }
+
+  protected function didRejectResult(PhabricatorPolicyInterface $object) {
+    $this->getPolicyFilter()->rejectObject(
+      $object,
+      $object->getPolicy(PhabricatorPolicyCapability::CAN_VIEW),
+      PhabricatorPolicyCapability::CAN_VIEW);
+  }
+
 
 /* -(  Policy Query Implementation  )---------------------------------------- */