corda / net.corda.client.fxutils / javafx.collections.ObservableList / leftOuterJoin

# leftOuterJoin

`fun <A : Any, B : Any, C, K : Any> ObservableList<A>.leftOuterJoin(rightTable: ObservableList<B>, leftToJoinKey: (A) -> K, rightToJoinKey: (B) -> K, assemble: (A, ObservableList<B>) -> C): ObservableList<C>`

data class Person(val name: String, val managerName: String) val people: ObservableList = (..) val managerEmployeeMapping: ObservableList<Pair<Person, ObservableList>> = people.leftOuterJoin(people, Person::name, Person::managerName) { manager, employees -> Pair(manager, employees) }

`fun <A : Any, B : Any, K : Any> ObservableList<A>.leftOuterJoin(rightTable: ObservableList<B>, leftToJoinKey: (A) -> K, rightToJoinKey: (B) -> K): ObservableMap<K, Pair<ObservableList<A>, ObservableList<B>>>`

data class Person(name: String, favouriteSpecies: Species) data class Animal(name: String, species: Species) val people: ObservableList = (..) val animals: ObservableList = (..) val peopleToFavouriteAnimals: ObservableMap<Species, Pair<ObservableList, ObservableList>> = people.leftOuterJoin(animals, Person::favouriteSpecies, Animal::species)

This is the most general left join, given a joining key it returns for each key a pair of relevant elements from the left and right tables. It is "left outer" in the sense that all members of the left table are guaranteed to be in the result, but this may not be the case for the right table.