structured data are fields in that record. This can include the meta-data for
that page, such as the page title.
-This plugin is meant to be used in conjunction with the B<field> plugin.
+This plugin is meant to be used in conjunction with the [[field]] plugin.
### USAGE
One can get the value of a field by using special markup in the page.
This does not use directive markup, in order to make it easier to
-use the markup inside other directives. There are two forms:
+use the markup inside other directives. There are four forms:
-* {{$*fieldname*}}
+* \{{$*fieldname*}}
This queries the value of *fieldname* for the source page.
<h1>My Long and Complicated Title With Potential For Spelling Mistakes</h1>
-* {{+$*fieldname*+}}
+* \{{$*pagename*#*fieldname*}}
+
+ This queries the value of *fieldname* for the page *pagename*.
+
+ For example:
+
+ On PageFoo:
+
+ \[[!meta title="I Am Page Foo"]]
+
+ Stuff about Foo.
+
+ On PageBar:
+
+ For more info, see \[[\{{$PageFoo#title}}|PageFoo]].
+
+ When PageBar is displayed:
+
+ <p>For more info, see <a href="PageFoo">I Am Page Foo</a>.</p>
+
+* \{{+$*fieldname*+}}
This queries the value of *fieldname* for the destination page; that is,
the value when this page is included inside another page.
<h1>I Am Page B</h1>
<p>Stuff about A.</p>
+* \{{+$*pagename*#*fieldname*+}}
+
+ This queries the value of *fieldname* for the page *pagename*; the
+ only difference between this and \{{$*pagename*#*fieldname*}} is
+ that the full name of *pagename* is calculated relative to the
+ destination page rather than the source page.
+
+ I can't really think of a reason why this should be needed, but
+ this format has been added for completeness.
+
+### Escaping
+
+Getfield markup can be escaped by putting a backwards slash `\`
+in front of the markup.
+If that is done, then the markup is displayed as-is.
+
+### No Value Found
+
+If no value is found for the given field, then the field name is returned.
+
+For example:
+
+On PageFoo:
+
+ \[[!meta title="Foo"]]
+ My title is {{$title}}.
+
+ My description is {{$description}}.
+
+When PageFoo is displayed:
+
+ <p>My title is Foo.</p>
+
+ <p>My description is description.</p>
+
+This is because "description" hasn't been defined for that page.
+
### More Examples
Listing all the sub-pages of the current page:
\[[!map pages="{{$page}}/*"]]
-### LIMITATIONS
-
-One cannot query the values of fields on pages other than the current
-page or the destination page.
-
## DOWNLOAD
* browse at GitHub: <http://github.com/rubykat/ikiplugins/blob/master/IkiWiki/Plugin/getfield.pm>