Ensure we do not set data attributes to the string "undefined"

Author: corylown

app/assets/javascripts/spotlight/spotlight.esm.js

@@ -53,10 +53,10 @@ SirTrevor.Blocks.SolrDocumentsBase = (function(){
       var iiifFields = [
         '<input type="hidden" name="item[' + index + '][thumbnail_image_url]" value="' + (autocomplete_data.thumbnail_image_url || autocomplete_data.thumbnail || "") + '"/>',
         '<input type="hidden" name="item[' + index + '][full_image_url]" value="' + (autocomplete_data.full_image_url || autocomplete_data.thumbnail_image_url || autocomplete_data.thumbnail || "") + '"/>',
-        '<input type="hidden" name="item[' + index + '][iiif_tilesource]" value="' + (autocomplete_data.iiif_tilesource) + '"/>',
-        '<input type="hidden" name="item[' + index + '][iiif_manifest_url]" value="' + (autocomplete_data.iiif_manifest_url) + '"/>',
-        '<input type="hidden" name="item[' + index + '][iiif_canvas_id]" value="' + (autocomplete_data.iiif_canvas_id) + '"/>',
-        '<input type="hidden" name="item[' + index + '][iiif_image_id]" value="' + (autocomplete_data.iiif_image_id) + '"/>',
+        '<input type="hidden" name="item[' + index + '][iiif_tilesource]" value="' + (autocomplete_data.iiif_tilesource || "") + '"/>',
+        '<input type="hidden" name="item[' + index + '][iiif_manifest_url]" value="' + (autocomplete_data.iiif_manifest_url || "") + '"/>',
+        '<input type="hidden" name="item[' + index + '][iiif_canvas_id]" value="' + (autocomplete_data.iiif_canvas_id || "") + '"/>',
+        '<input type="hidden" name="item[' + index + '][iiif_image_id]" value="' + (autocomplete_data.iiif_image_id || "") + '"/>',
       ];
 
       // The region input is required for widgets that enable image cropping but not otherwise