rename preprocessordirective to directive

Reasons include:
- easier to type
- might want postprocessor directives again sometime, and listdirectives
  can then use the directive/* files for either
- that it's done as a preprocessor step is an internal detail (and not a
  very accurate one, really :-)

1 files changed, 39 insertions, 0 deletions

diff --git a/doc/ikiwiki/directive.mdwn b/doc/ikiwiki/directive.mdwn
new file mode 100644
index 000000000..9a01aaa82
--- /dev/null
+++ b/doc/ikiwiki/directive.mdwn
@@ -0,0 +1,39 @@
+[[!meta robots="noindex, follow"]]
+Directives are similar to a [[WikiLink]] in form, except they
+begin with `!` and may contain parameters. The general form is:
+
+	\[[!directive param="value" param="value"]]
+
+This gets expanded before the rest of the page is processed, and can be used
+to transform the page in various ways.
+
+The quotes around values can be omitted if the value is a simple word.
+Also, some directives may use parameters without values, for example:
+
+	\[[!tag foo]]
+
+A directive does not need to all be on one line, it can be
+wrapped to multiple lines if you like:
+	
+	\[[!directive foo="baldersnatch"
+	bar="supercalifragalisticexpealadocious" baz=11]]
+
+Also, multiple lines of *quoted* text can be used for a value.
+To allow quote marks inside the quoted text, delimit the block
+of text with triple-quotes:
+
+	\[[!directive text="""
+	1. "foo"
+	2. "bar"
+	3. "baz"
+	"""]]
+
+ikiwiki also has an older syntax for directives, which requires a
+space in directives to distinguish them from [[wikilinks|wikilink]].  This
+syntax has several disadvantages: it requires a space after directives with no
+parameters (such as `\[[pagecount ]]`), and it prohibits spaces in
+[[wikilinks|wikilink]].  ikiwiki now provides the `!`-prefixed syntax shown
+above as the preferred alternative.  However, ikiwiki still supports wikis
+using the older syntax, if the `prefix_directives` option is not enabled.
+For backward compatibility with existing wikis, this option currently
+defaults to off, so ikiwiki supports the old syntax.