A UI for selecting multiple records using an ajax lookup.
// todo: finish this example
name: POST unique field name.
single: text label of the items.
joiner_local_col: column name within the joiner table for referencing local table, optional default is singular of local table + '_id'.
joiner_foreign_col: column name within the joiner table for referencing foreign table, optional default is singular of foreign table + '_id'.
joiner_table: name of joiner table.
foreign_table: name of the foreign table.
foreign_label_col: label of items of the foreign table. Can be a string for a single column or an array of columns, which will be joined with a space
foreign_label_sql: if provided, then foreign_label_col is ignored, and this SQL expression will be used instead. The table is aliased to item. A common use would be CONCAT with custom joining strings.
lookup_url: method to return json list of results.
min_term_length: minimum number of characters to prevoke search on.
reorder: are the items ordered? true = manual reordering, false = alpha reordering