From 63fc0bc562f2b608e96d9fa54eaa2f1f00b5f2de Mon Sep 17 00:00:00 2001
From: pmario <pmariojo@gmail.com>
Date: Mon, 13 May 2024 12:58:04 +0200
Subject: [PATCH] add cascade to check if macro prams and fields are valid. eg
 Caption has a value

---
 core/wiki/macros/toc.tid | 33 +++++++++++++++++++--------------
 1 file changed, 19 insertions(+), 14 deletions(-)

diff --git a/core/wiki/macros/toc.tid b/core/wiki/macros/toc.tid
index f99d9523a..ca5df085b 100644
--- a/core/wiki/macros/toc.tid
+++ b/core/wiki/macros/toc.tid
@@ -17,26 +17,31 @@ The very first toc macro is _not_ reused. So it can be used as a simple referenc
 
 \whitespace trim
 
+<!-- The field to show depends on the following cascade - default: title -->
+\procedure _hasItemTemplate() [<itemTemplate>!is[blank]then[text]]
+\procedure _hasCaptionField() [get<captionField>!is[blank]then<captionField>]
+\procedure _hasCaption() [has[caption]then[caption]]
+
+<!-- Use this item template as a default -->
 \procedure toc-defaultItemTemplate()
-<span class="tc-toc-caption tc-tiny-gap-left" title={{{ [{!!toc-tooltip}!is[blank]] :else[<currentTiddler>] }}}>
-<$let tv-wikilinks="no">
-	<$transclude $tiddler={{{ [<itemTemplate>!is[blank]then<itemTemplate>else<currentTiddler>] }}}
-		$field={{{ [<itemTemplate>!is[blank]then[text]]
-			:else[<captionField>!is[blank]then<captionField>] }}}
+<$let tv-wikilinks="no"
+	field={{{ [<currentTiddler>] :cascade[<_hasItemTemplate>append<_hasCaptionField>append<_hasCaption>append[title]] }}}
+>
+	<span class="tc-tiny-gap-left"
+		data-fieldClass=`field-$(field)$`
+		title={{{ [{!!toc-tooltip}!is[blank]] :else[<currentTiddler>] }}}
 	>
-		<$transclude $field={{{ [{!!caption}!is[blank]then[caption]else[title]] }}}>
-			<$view field="title"/>
-		</$transclude>
-	</$transclude>
-	<$log/>
+		<$transclude $field=<<field>>/>
+	</span>
 </$let>
-</span>
 \end
 
-<!-- Returns the title of a tiddler -->
-\function tf.toc-getItemTemplateTitle() [<itemTemplate>!is[blank]then<itemTemplate>] :else[<currentTiddler>get[toc-itemTemplate]]
+<!--
+Check if a user defined item template should be used.
+It can be a macro parameter: itemTemplate or a tiddler field: toc-itemTemplate. 
+-->
+\function tf.toc-getItemTemplateTitle() [<currentTiddler>get[toc-itemTemplate]] :filter[has[text]] :else[<itemTemplate>has[text]then<itemTemplate>]
 
-<!-- Use macro itemTemplate or one defined as a toc-itemTemplate field -->
 \procedure _itemTemplate()
 <$transclude $tiddler=<<tf.toc-getItemTemplateTitle>> >
 	<<toc-defaultItemTemplate>>