external plugin in your favorite programming language. Wow us at how much
easier you can do the same thing in your favorite language. ;-)
+There's now a second external plugin, the [[rst]] plugin, written in
+python. It uses a `proxy.py`, a helper library for ikiwiki python plugins.
+
+[[toc ]]
+
## How external plugins use XML RPC
While XML RPC is typically used over http, ikiwiki doesn't do that.
call `getvar("config", "url")`. To set it, call
`setvar("config", "url", "http://example.com/)`.
+The `%pagestate` is a special hash with a more complex format. To access
+it, external plugins can use the `getstate` and `setstate` RPCs. To access
+stored state, call `getstate("page", "id", "key")`, and to store state,
+call `setstate("page", "id", "key", "value")`.
+
## Notes on function parameters
The [[plugin_interface_documentation|write]] talks about functions that take
"Ikiwiki::rcs_update" and "call" is the RPC call ikiwiki will make whenever
that function is run.
+If the RPC call is memoizable, you can also pass a "memoize" parameter, set
+to 1.
+
## Limitations of XML RPC
Since XML RPC can't pass around references to objects, it can't be used
with functions that take or return such references. That means you can't
-use XML RPC for `cgi` or `formbuilder` hooks (which are passed CGI and
+100% use XML RPC for `cgi` or `formbuilder` hooks (which are passed CGI and
FormBuilder perl objects), or use it to call `template()` (which returns a
perl HTML::Template object).
Injecting a replacement for a commonly called ikiwiki function
could result in a lot more RPC calls than expected and slow
eveything down. `pagetitle`, for instance, is called about 100 times
-per page build.
+per page build. Whenever possible, you should tell ikiwiki to memoize
+injected functions.
In general, use common sense, and your external plugin will probably
perform ok.