Make custom "date" field feed stories human-readable

Summary: Fixes T10130.

Test Plan: {F1060142}

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T10130

Differential Revision: https://secure.phabricator.com/D15004

src/infrastructure/customfield/standard/PhabricatorStandardCustomFieldDate.php

@@ -191,6 +191,42 @@ final class PhabricatorStandardCustomFieldDate
     }
   }
 
+  public function getApplicationTransactionTitleForFeed(
+    PhabricatorApplicationTransaction $xaction) {
+
+    $viewer = $this->getViewer();
+
+    $author_phid = $xaction->getAuthorPHID();
+    $object_phid = $xaction->getObjectPHID();
+
+    $old = $xaction->getOldValue();
+    $new = $xaction->getNewValue();
+
+    if (!$old) {
+      return pht(
+        '%s set %s to %s on %s.',
+        $xaction->renderHandleLink($author_phid),
+        $this->getFieldName(),
+        phabricator_datetime($new, $viewer),
+        $xaction->renderHandleLink($object_phid));
+    } else if (!$new) {
+      return pht(
+        '%s removed %s on %s.',
+        $xaction->renderHandleLink($author_phid),
+        $this->getFieldName(),
+        $xaction->renderHandleLink($object_phid));
+    } else {
+      return pht(
+        '%s changed %s from %s to %s on %s.',
+        $xaction->renderHandleLink($author_phid),
+        $this->getFieldName(),
+        phabricator_datetime($old, $viewer),
+        phabricator_datetime($new, $viewer),
+        $xaction->renderHandleLink($object_phid));
+    }
+  }
+
+
   public function shouldAppearInConduitTransactions() {
     // TODO: Dates are complicated and we don't yet support handling them from
     // Conduit.