external: Work around XML RPC's lack of support for null by passing a special sentina...

diff --git a/debian/changelog b/debian/changelog
index 2169f310d2029b9d67fddc89c04b1ccd60e29715..1b046b20c152b81d15ebc795bd6c6620a6111ee2 100644 (file)
--- a/debian/changelog
+++ b/debian/changelog
@@ -59,6 +59,8 @@ ikiwiki (2.41) UNRELEASED; urgency=low
   * inline: Crazy optimisation to work around slow markdown.
   * Precompile pagespecs, about 10% overall speedup.
   * Changed to a binary index file, written using Storable, for speed.
   * inline: Crazy optimisation to work around slow markdown.
   * Precompile pagespecs, about 10% overall speedup.
   * Changed to a binary index file, written using Storable, for speed.

+  * external: Work around XML RPC's lack of support for null by passing
+    a special sentinal value.

 
  -- martin f. krafft <madduck@debian.org>  Sun, 02 Mar 2008 17:46:38 +0100
 
 
  -- martin f. krafft <madduck@debian.org>  Sun, 02 Mar 2008 17:46:38 +0100
 

diff --git a/doc/plugins/write/external.mdwn b/doc/plugins/write/external.mdwn
index 4492cd0dabe439bb11c3c2a4b9d6815111fb08e9..bda34b77188301c67cdf30c7dc85ac5ab492c008 100644 (file)
--- a/doc/plugins/write/external.mdwn
+++ b/doc/plugins/write/external.mdwn
@@ -79,6 +79,19 @@ Other languages might not find it so easy. If not, it might be a good idea
 to convert these named parameters into something more natural for the
 language as part of their XML RPC interface.
 
 to convert these named parameters into something more natural for the
 language as part of their XML RPC interface.
 

+## undef
+
+XML RPC has a limitation that it does not have a way to pass
+undef/NULL/None. There is an extension to the protocol that supports this,
+but it is not yet available in the [[cpan XML::RPC]] library used by
+ikiwiki.
+
+Until the extension is available, ikiwiki allows undef to be communicated
+over XML RPC by passing a sentinal value, a hash with a single key "null"
+with a value of an empty string. External plugins that need to communicate
+null values to or from ikiwiki will have to translate between undef and
+the sentinal.
+

 ## Function injection
 
 Some parts of ikiwiki are extensible by adding functions. For example, the
 ## Function injection
 
 Some parts of ikiwiki are extensible by adding functions. For example, the