Qiita::Elasticsearch

Elasticsearch client helper for Qiita.

Usage

Qiita::Elasticsearch::QueryBuilder builds Elasticsearch query from query string.

query_builder = Qiita::Elasticsearch::QueryBuilder.new

query_builder.build("a")
#=> {"match"=>{"_all"=>"a"}}

query_builder.build("a b")
#=> {"bool"=>{"should"=>[{"match"=>{"_all"=>"a"}}, {"match"=>{"_all"=>"b"}}]}}

query_builder.build("a -b")
#=> {"filtered"=> {"filter"=>{"bool"=>{"_cache"=>true, "must_not"=>[{"match"=>{"_all"=>"b"}}]}}, "query"=>{"match"=>{"_all"=>"a"}}}}

query_builder.build('"a b"')
#=> {"match_phrase"=>{"_all"=>"a b"}}

query_builder.build("a OR b")
#=> {"bool"=>{"should"=>[{"match"=>{"_all"=>"a"}}, {"match"=>{"_all"=>"b"}}]}}

default_fields

Pass :default_fields option to tell default (matchable) field names (default: _all).

query_builder = Qiita::Elasticsearch::QueryBuilder.new(default_fields: ["body", "title"])

query_builder.build("a")
#=> {"multi_match"=>{"fields"=>["body", "title"], "query"=>"a"}}

filterable_fields

Pass :filterable_fields option to enable filtered queries like tag:Ruby.

query_builder = Qiita::Elasticsearch::QueryBuilder.new(filterable_fields: ["tag", "title"])

query_builder.build("tag:a")
#=> {"filtered"=>{"filter"=>{"term"=>{"tag"=>"a"}}}}

query_builder.build("tag:a b")
#=> {"filtered"=>{"filter"=>{"term"=>{"tag"=>"a"}}, "query"=>{"match"=>{"_all"=>"b"}}}}

query_builder.build("user:a b")
#=> {"bool"=>{"should"=>[{"match"=>{"_all"=>"user:a"}}, {"match"=>{"_all"=>"b"}}]}}

hierarchal_fields

Pass :hierarchal_fields option with :filterable_fields to enable prefixed filtered queries. With this option, tag:foo will hit documents tagged with foo, or foo/....

query_builder = Qiita::Elasticsearch::QueryBuilder.new(filterable_fields: ["tag"], hierarchal_fields: ["tag"])

query_builder.build("tag:ruby")
#=> {"filtered"=>{"filter"=>{"bool"=>{"should"=>[{"prefix"=>{"tag"=>"ruby/"}}, {"term"=>{"tag"=>"ruby"}}]}}}}

int_fields

Pass :int_fields option with :filterable_fields to enable range filtered queries. With this option, stocks:>100 will hit documents stocked by greater than 100 users.

query_builder = Qiita::Elasticsearch::QueryBuilder.new(filterable_fields: ["stocks"], int_fields: ["stocks"])

query_builder.build("stocks:>100")
#=> {"filtered"=>{"filter"=>{"range"=>{"stocks"=>{"gt"=>100}}}}}

date_fields

Pass :date_fields option with :filterable_fields to enable date filtered queries. With this option, created_at:<2015-04-01 will hit documents created before 2015-04-01.

query_builder = Qiita::Elasticsearch::QueryBuilder.new(filterable_fields: ["created_at"], date_fields: ["created_at"])

query_builder.build("created_at:<2015-04-01")
#=> {"filtered"=>{"filter"=>{"range"=>{"created_at"=>{"lt"=>"2015-04-01"}}}}}

time_zone

Pass :time_zone option to tell how move range field's input to UTC time based date.

query_builder = Qiita::Elasticsearch::QueryBuilder.new(filterable_fields: ["created_at"], date_fields: ["created_at"], time_zone: "+09:00")

query_builder.build("created_at:<2015-04-16")
#=> {"filtered"=>{"filter"=>{"range"=>{"created_at"=>{"lt"=>"2015-04-16","time_zone"=>"+09:00"}}}}}

downcased_fields

Pass :downcased_fields option with :filterable_fields to downcase any terms in the fields. This option is useful when some fields are stored within downcased format on Elasticsearch.

query_builder = Qiita::Elasticsearch::QueryBuilder.new(downcased_fields: ["tag"], filterable_fields: ["tag"])

query_builder.build("tag:Ruby")
#=> {"filtered"=>{"filter"=>{"term"=>{"tag"=>"ruby"}}}}

field_mapping

Pass :field_mapping option to search with aliases of field names. Users can search with alias fields which could not exist in the mapping of Elasticsearch nodes.

query_builder = Qiita::Elasticsearch::QueryBuilder.new(field_mapping: { "headline" =>  ["title", "title.ngram"]} )

query_builder.build("headline:Ruby")
#=> {"multi_match"=>{ "fields"=>["title", "title.ngram"], "query"=>"Ruby"}