[folks] inspect: Implement pretty printing of GDateTime

[Philip Withnall <pwithnall src gnome org>]

commit 1c3357fb0c32855f5423e5b88127f2b4cfb1baa5
Author: Philip Withnall <philip tecnocode co uk>
Date:   Mon Jun 18 10:32:49 2012 +0100

    inspect: Implement pretty printing of GDateTime
    
    The new Zeitgeist work in the Telepathy backend makes use of nullable
    GDateTimes, so this implements pretty printing of them in folks-inspect.
    
    Everyone prefers reading well-formatted ISO 8601 date/times over reading
    error messages saying the conversion wasnât possible, right?

 tools/inspect/utils.vala |   14 ++++++++++++++
 1 files changed, 14 insertions(+), 0 deletions(-)
---
diff --git a/tools/inspect/utils.vala b/tools/inspect/utils.vala
index d14c6ce..cf5f98c 100644
--- a/tools/inspect/utils.vala
+++ b/tools/inspect/utils.vala
@@ -39,6 +39,8 @@ private class Folks.Inspect.Utils
           typeof (string), Utils.transform_persona_store_to_string);
       Value.register_transform_func (typeof (string[]), typeof (string),
           Utils.transform_string_array_to_string);
+      Value.register_transform_func (typeof (DateTime), typeof (string),
+          Utils.transform_date_time_to_string);
     }
 
   private static void transform_object_to_string (Value src,
@@ -74,6 +76,18 @@ private class Folks.Inspect.Utils
       dest = (owned) output;
     }
 
+  private static void transform_date_time_to_string (Value src, out Value dest)
+    {
+      unowned DateTime? date_time = (DateTime?) src;
+      string output = "(null)";
+      if (date_time != null)
+        {
+          output = ((!) date_time).format ("%FT%T%z");
+        }
+
+      dest = (owned) output;
+    }
+
   public static void indent ()
     {
       /* We indent in increments of two spaces */