Document channel-specific and private configuration variables.

develop/advanced_plugin_config.rst

@@ -125,6 +125,7 @@ Using Config Groups
   A brief overview of how to use config groups to organize config variables
 
 Supybot's Hierarchical Configuration
+------------------------------------
 
 Supybot's configuration is inherently hierarchical, as you've probably already
 figured out in your use of the bot. Naturally, it makes sense to allow plugin
@@ -146,7 +147,7 @@ find that we do this in a handful of spots yet we use the "values as groups"
 feature quite a bit.
 
 Creating a Config Group
-=======================
+-----------------------
 
 As stated before, config variables themselves are groups, so you can create a
 group simply by creating a configuration variable::
@@ -177,7 +178,7 @@ course, the group name. So now we have WorldDom.attackTargets (or, fully,
 supybot.plugins.WorldDom.attackTargets).
 
 Adding Values to a Group
-========================
+------------------------
 
 Actually, you've already done this several times, just never to a custom group
 of your own. You've always added config values to your plugin's config group.
@@ -193,6 +194,34 @@ argument is WorldDom.attackTargets, our new group. Make sure that the
 conf.registerGroup call is made before this one or else you'll get a nasty
 AttributeError.
 
+Variations
+----------
+
+Channel-specific values
+^^^^^^^^^^^^^^^^^^^^^^^
+
+A very handy feature is channel-specific variables, which allows bot
+administrators to set a global value (as for non-channel-specific values
+AND another value for specific channels).
+
+The syntax is pretty much like the previous one, except we use
+`registerChannelValue` instead of `registerGlobalValue`::
+
+    conf.registerChannelValue(WorldDom.attackTargets, 'air',
+        registry.SpaceSeparatedListOfStrings('', """Contains the list of air
+                                                    targets."""))
+
+Private values
+^^^^^^^^^^^^^^
+
+Variable type also take an optional argument, for setting a configuration
+variable to private (useful for passwords, authentication tokens,
+api keys, …)::
+
+    conf.registerChannelValue(WorldDom.attackTargets, 'air',
+        registry.SpaceSeparatedListOfStrings('', """Contains the list of air
+            targets.""", private=True))
+
 The Built-in Registry Types
 ===========================
   A rundown of all of the built-in registry types available for use with config