{{ source.valueProp === undefined || source.valueProp == null || source.valueProp.length === 0 ? item : item[source.valueProp] }}
{{dir === 'rtl' ? '⇐' : '⇒'}}
⇓
{{ dest.valueProp === undefined || dest.valueProp === null || dest.valueProp.length === 0 ? item : item[dest.valueProp] }}