Expression Language Tricks

1. Concatenation: Looking up a composite key in a dictionary

#{messages[‘org.sample.’concat(userHome.type)]}

2. Conditional composite String output

#{condition?’ok': messages[‘ex.pression1′].concat(‘  ‘).concat(messages[‘ex.pression2′])}

3. Projections: Looping over a collection and printing one field

#{book.address}

#{book.address.{a|a.name}}

Source: Seam Documentation