Configuration

constructor

elasticlunr.Configuration()

Option name	Type	Description
config	String	user configuration
fields	Array	fields of index instance

elasticlunr.Configuration is used to analyze the user search configuration.

By elasticlunr.Configuration user could set query-time boosting, boolean model in each field.

Currently configuration supports:

query-time boosting, user could set how to boost each field.
boolean model chosing, user could choose which boolean model to use for each field.
token expandation, user could set token expand to True to improve Recall. Default is False.

Query time boosting must be configured by field category, "boolean" model could be configured
by both field category or globally as the following example. Field configuration for "boolean"
will overwrite global configuration.
Token expand could be configured both by field category or golbally. Local field configuration will
overwrite global configuration.

configuration example:
{
fields:{
title: {boost: 2},
body: {boost: 1}
},
bool: "OR"
}

"bool" field configuation overwrite global configuation example:
{
fields:{
title: {boost: 2, bool: "AND"},
body: {boost: 1}
},
bool: "OR"
}

"expand" example:
{
fields:{
title: {boost: 2, bool: "AND"},
body: {boost: 1}
},
bool: "OR",
expand: true
}

"expand" example for field category:
{
fields:{
title: {boost: 2, bool: "AND", expand: true},
body: {boost: 1}
},
bool: "OR"
}

setting the boost to 0 ignores the field (this will only search the title):
{
fields:{
title: {boost: 1},
body: {boost: 0}
}
}

then, user could search with configuration to do query-time boosting.
idx.search('oracle database', {fields: {title: {boost: 2}, body: {boost: 1}}});

elasticlunr.Configuration = function (config, fields) {
  var config = config || '';

  if (fields == undefined || fields == null) {
    throw new Error('fields should not be null');
  }

  this.config = {};

  var userConfig;
  try {
    userConfig = JSON.parse(config);
    this.buildUserConfig(userConfig, fields);
  } catch (error) {
    elasticlunr.utils.warn('user configuration parse failed, will use default configuration');
    this.buildDefaultConfig(fields);
  }
};

buildDefaultConfig

method

elasticlunr.Configuration.prototype.buildDefaultConfig()

Option name	Type	Description
fields	Array	fields of index instance

Build default search configuration.

elasticlunr.Configuration.prototype.buildDefaultConfig = function (fields) {
  this.reset();
  fields.forEach(function (field) {
    this.config[field] = {
      boost: 1,
      bool: "OR",
      expand: false
    };
  }, this);
};

buildUserConfig

method

elasticlunr.Configuration.prototype.buildUserConfig()

Option name	Type	Description
config	JSON	User JSON configuratoin
fields	Array	fields of index instance

Build user configuration.

elasticlunr.Configuration.prototype.buildUserConfig = function (config, fields) {
  var global_bool = "OR";
  var global_expand = false;

  this.reset();
  if ('bool' in config) {
    global_bool = config['bool'] || global_bool;
  }

  if ('expand' in config) {
    global_expand = config['expand'] || global_expand;
  }

  if ('fields' in config) {
    for (var field in config['fields']) {
      if (fields.indexOf(field) > -1) {
        var field_config = config['fields'][field];
        var field_expand = global_expand;
        if (field_config.expand != undefined) {
          field_expand = field_config.expand;
        }

        this.config[field] = {
          boost: (field_config.boost || field_config.boost === 0) ? field_config.boost : 1,
          bool: field_config.bool || global_bool,
          expand: field_expand
        };
      } else {
        elasticlunr.utils.warn('field name in user configuration not found in index instance fields');
      }
    }
  } else {
    this.addAllFields2UserConfig(global_bool, global_expand, fields);
  }
};

addAllFields2UserConfig

method

elasticlunr.Configuration.prototype.addAllFields2UserConfig()

Option name	Type	Description
bool	String	Boolean model
expand	String	Expand model
fields	Array	fields of index instance

Add all fields to user search configuration.

elasticlunr.Configuration.prototype.addAllFields2UserConfig = function (bool, expand, fields) {
  fields.forEach(function (field) {
    this.config[field] = {
      boost: 1,
      bool: bool,
      expand: expand
    };
  }, this);
};

get

method

elasticlunr.Configuration.prototype.get()

get current user configuration

elasticlunr.Configuration.prototype.get = function () {
  return this.config;
};

reset

method

elasticlunr.Configuration.prototype.reset()

reset user search configuration.

elasticlunr.Configuration.prototype.reset = function () {
  this.config = {};
};