Add documentation of template system.

Fixes bug MKWS-68.

diff --git a/tools/htdocs/whitepaper.markdown b/tools/htdocs/whitepaper.markdown
index dce4f30..3ff637c 100644 (file)
--- a/tools/htdocs/whitepaper.markdown
+++ b/tools/htdocs/whitepaper.markdown
@@ -205,6 +205,40 @@ day, a welcome message or a help page. This can be done by placing an
 but will be hidden when a search is made.
 
 
+### Customised display using Handlebars templates
+
+Certain aspects of the widget-set's display can be customised by
+providing Handlebars templates with well-known IDs that begin with the
+string `mkwsTemplate`. At present, the supported templates are:
+
+* `mkwsTemplateSummary` -- used for each summary record in a list of
+  results.
+
+* `mkwsTemplateRecord` -- used when displaying a full record.
+
+For both of these the metadata record is passed in, and its fields can
+be referenced in the template. As well as the metadata fields
+(`md-*`), two special fields are provided to the `mkwsTemplateSummary`
+template, for creating popup links for full records. These are `_id`,
+which must be provided as the `id` attribute of a link tag, and
+`_onclick`, which must be provided as the `onclick` attribute.
+
+For example, an application can install a simple author+title summary
+record in place of the usual one providing the following template:
+
+        <script id="mkwsTemplateSummary" type="text/x-handlebars-template">
+          {{#if md-author}}
+            <span>{{md-author}}</span>
+          {{/if}}
+          <a href="#" id="{{_id}}" onclick="{{_onclick}}">
+            <b>{{md-title}}</b>
+          </a>
+        </script>
+
+For details of Handlebars template syntax, see
+[the online documentation](http://handlebarsjs.com/).
+
+
 ### Responsive design
 
 Metasearching applications may need to appear differently on