/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.solr.search;
import org.apache.solr.common.params.SolrParams;
import org.apache.solr.request.SolrQueryRequest;
/**
* Create a dismax query from the input value.
* <br>localParams are checked before global request params.
* <br>Example: <code>{!dismax qf='myfield mytitle^2'}foo</code> creates a dismax query across
* across myfield and mytitle, with a higher weight on mytitle.
*
* <p>
* A Generic query plugin designed to be given a simple query expression
* from a user, which it will then query against a variety of
* pre-configured fields, in a variety of ways, using BooleanQueries,
* DisjunctionMaxQueries, and PhraseQueries.
* </p>
*
* <p>
* All of the following options may be configured for this plugin
* in the solrconfig as defaults, and may be overriden as request parameters
* </p>
*
* <ul>
* <li>q.alt - An alternate query to be used in cases where the main
* query (q) is not specified (or blank). This query should
* be expressed in the Standard SolrQueryParser syntax (you
* can use <code>q.alt=*:*</code> to denote that all documents
* should be returned when no query is specified)
* </li>
* <li>tie - (Tie breaker) float value to use as tiebreaker in
* DisjunctionMaxQueries (should be something much less than 1)
* </li>
* <li> qf - (Query Fields) fields and boosts to use when building
* DisjunctionMaxQueries from the users query. Format is:
* "<code>fieldA^1.0 fieldB^2.2</code>".
* This param can be specified multiple times, and the fields
* are additive.
* </li>
* <li> mm - (Minimum Match) this supports a wide variety of
* complex expressions.
* read {@link org.apache.solr.util.SolrPluginUtils#setMinShouldMatch SolrPluginUtils.setMinShouldMatch} and <a href="{@docRoot}/org/apache/solr/util/doc-files/min-should-match.html">mm expression format</a> for details.
* </li>
* <li> pf - (Phrase Fields) fields/boosts to make phrase queries out
* of, to boost the users query for exact matches on the specified fields.
* Format is: "<code>fieldA^1.0 fieldB^2.2</code>".
* This param can be specified multiple times, and the fields
* are additive.
* </li>
* <li> ps - (Phrase Slop) amount of slop on phrase queries built for pf
* fields.
* </li>
* <li> qs - (Query Slop) amount of slop on phrase queries explicitly
* specified in the "q" for qf fields.
* </li>
* <li> bq - (Boost Query) a raw lucene query that will be included in the
* users query to influence the score. If this is a BooleanQuery
* with a default boost (1.0f), then the individual clauses will be
* added directly to the main query. Otherwise, the query will be
* included as is.
* This param can be specified multiple times, and the boosts are
* are additive. NOTE: the behaviour listed above is only in effect
* if a single <code>bq</code> paramter is specified. Hence you can
* disable it by specifying an additional, blank, <code>bq</code>
* parameter.
* </li>
* <li> bf - (Boost Functions) functions (with optional boosts) that will be
* included in the users query to influence the score.
* Format is: "<code>funcA(arg1,arg2)^1.2
* funcB(arg3,arg4)^2.2</code>". NOTE: Whitespace is not allowed
* in the function arguments.
* This param can be specified multiple times, and the functions
* are additive.
* </li>
* <li> fq - (Filter Query) a raw lucene query that can be used
* to restrict the super set of products we are interested in - more
* efficient then using bq, but doesn't influence score.
* This param can be specified multiple times, and the filters
* are additive.
* </li>
* </ul>
*
* <p>
* The following options are only available as request params...
* </p>
*
* <ul>
* <li> q - (Query) the raw unparsed, unescaped, query from the user.
* </li>
* <li>sort - (Order By) list of fields and direction to sort on.
* </li>
* </ul>
*
*/
public class DisMaxQParserPlugin extends QParserPlugin {
public static final String NAME = "dismax";
@Override
public QParser createParser(String qstr, SolrParams localParams, SolrParams params, SolrQueryRequest req) {
return new DisMaxQParser(qstr, localParams, params, req);
}
}