KING

filter

• There is a faceted Search, which is to preview the result of the query in many category.
  • like if we search for ‘apple’
    • the result may be classified into two
      • one is apple fruit
      • one is apple company
• actually, this is a filter.
  • we can classify before index, and store into index
  • and use value to filter them when query

how to build filter value

• use Document::add_value

how to use filter when query

• two ways
  • one is use Xapian::MatchDecider, this return a bool value.
    • or we can use Xapian::ValueSetMatchDecider
      • Xapian::ValueSetMatchDecider(slot, inclusive)
        • slot means which slot to filter
        • inclusive means using filter or reduce
      • use Xapian::ValueSetMatchDecider::add_value(string)
        • user can decide one or many set of value
          • when document belong to one of these value
            • make it filter or stay
  • use MatchSpy