double backticks

lib/ProductOpener/KnowledgePanels.pm

@@ -273,6 +273,8 @@ sub create_knowledge_panels ($product_ref, $target_lc, $target_cc, $options_ref,
 Helper function to allow to enter multiline strings in JSON templates.
 The function converts the multiline string into a single line string.
 
+New lines are converted to \n, and quotes " and \ are escaped if not escaped already.
+
 =cut
 
 sub convert_multiline_string_to_singleline ($line) {
@@ -287,6 +289,30 @@ sub convert_multiline_string_to_singleline ($line) {
 	return '"' . $line . '"';
 }
 
+=head2 convert_multiline_string_to_singleline_without_line_breaks_and_extra_spaces($line)
+
+Helper function to allow to enter multiline strings in JSON templates.
+The function converts the multiline string into a single line string.
+
+Line breaks are converted to spaces, and multiple spaces are converted to a single space.
+
+This function is useful in templates where we use IF statements etc. to generate a single value like a title.
+
+=cut
+
+sub convert_multiline_string_to_singleline_without_line_breaks_and_extra_spaces ($line) {
+
+	# Escape " and \ unless they have been escaped already
+	# negative look behind to not convert \n to \\n or \" to \\" or \\ to \\\\
+	$line =~ s/(?<!\\)("|\\)/\\$1/g;
+
+	$line =~ s/\s+/ /g;
+	$line =~ s/^\s+//;
+	$line =~ s/\s+$//;
+
+	return '"' . $line . '"';
+}
+
 =head2 create_panel_from_json_template ( $panel_id, $panel_template, $panel_data_ref, $product_ref, $target_lc, $target_cc, $options_ref )
 
 Creates a knowledge panel from a JSON template.
@@ -301,6 +327,8 @@ Some special features that are not included in the JSON format are supported:
 - The multiline strings will be converted to a single string.
 - Quotes " are automatically escaped unless they are already escaped
 
+Using two backticks at the start and end of the string removes line breaks and extra spaces.
+
 3. Comments can be included by starting a line with //
 - Comments will be removed in the resulting JSON, they are only intended to make the source template easier to understand.
 
@@ -386,6 +414,8 @@ sub create_panel_from_json_template ($panel_id, $panel_template, $panel_data_ref
 
 		# Also escape quotes " to \"
 
+		$panel_json
+			=~ s/\`\`([^\`]*)\`\`/convert_multiline_string_to_singleline_without_line_breaks_and_extra_spaces($1)/seg;
 		$panel_json =~ s/\`([^\`]*)\`/convert_multiline_string_to_singleline($1)/seg;
 
 		# Remove trailing commas at the end of a string delimited by quotes

templates/api/knowledge-panels/health/ingredients/ingredient.tt.json

@@ -10,18 +10,28 @@
     "expanded": false,
     [% END %]
     "title_element": {
-        // Note: the app displays line feeds as line feeds...
-        "title": `        [% dash = "-" %]        [% dash.repeat(panel.level) %]        [% display_taxonomy_tag_name("ingredients", panel.ingredient_id) %]        [% IF panel.ingredient.percent.defined %]            ([% round(panel.ingredient.percent) %]%)        [% ELSIF panel.ingredient.percent_estimate.defined %]            ([% round(panel.ingredient.percent_estimate) %]% [% lang("estimate") %])        [% END %]        `,
+        // double backticks: convert to a single line without newlines and extra spaces
+        "title": ``
+        [% dash = "-" %]
+        [% dash.repeat(panel.level) %]
+
+        [% display_taxonomy_tag_name("ingredients", panel.ingredient_id) %]
+        [% IF panel.ingredient.percent.defined %]
+            ([% round(panel.ingredient.percent) %]%)
+        [% ELSIF panel.ingredient.percent_estimate.defined %]
+            ([% round(panel.ingredient.percent_estimate) %]% [% lang("estimate") %])
+        [% END %]
+        ``,
     },        
     "elements": [
-        [% IF panel.ingredient_description -%]
+        [% IF panel.ingredient_description %]
         {
             "element_type": "text",
             "text_element": {
                 "html": `[% panel.ingredient_description %]`
             }
         }
-        [% ELSIF panel.wikipedia_abstract -%]
+        [% ELSIF panel.wikipedia_abstract %]
         {
             "element_type": "text",
             "text_element": {