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This is an advanced search plugin for Blacklight ( www.projectblacklight.org ).

• The Blacklight plugin ( github.com/projectblacklight/blacklight )

  • NOTE: Blacklight 3.x is required for current version of Advanced Search plugin

  • advanced search plugin 0.12.0 will work with Blacklight 2.9/Rails2.

  • Older tagged versions of Advanced Search may work with older BL.

Add to your application’s Gemfile:

gem "blacklight_advanced_search"

then run ‘bundle install’. Then run:

rails generate blacklight_advanced_search

• The ‘generate’ command will copy some stylesheet/javascript assets to your local app (this architecture will likely change for Rails 3.1)

• It will also OPTIONALLY install a config/initializers/blacklight_advanced_search.rb . Configuration in the initializer is optional, for many setups no configuration will be neccesary. See ‘Configuration’ section below.

• And it can optionally install a localized search form with a link to advanced search. If you’ve already localized your search form you’ll want to do this manually instead.

You may want to set BlacklightAdvancedSearch.config = true to enable AND/OR/NOT parsing even in ordinary search, this is not on by default.

Clone the advanced search plugin from github into your application’s vendor/plugins directory , and switch to a version that works with BL 2.x/Rails2.

• cd into your application’s vendor/plugins directory and run the following command:

git clone http://github.com/projectblacklight/blacklight_advanced_search.git
git checkout v0.12.0

You can later use standard git commands to update the plugin to a new version.

You will now need to add a parslet gem dependency to your app, since blacklight_advanced_search is not currently a gem itself, you have to do this manually. Add “config.gem ‘parslet’” to your config/environment.rb, and then run:

sudo rake gems:install

You can also now optionally run the installer script to install some optional example configuration files. In many cases, no configuration is needed for advanced search plugin to work.

• cd back to your application’s root directory

cd ../../

• And then run the the following command:

rake rails:template LOCATION=vendor/plugins/blacklight_advanced_search/template.rb

You may want to set BlacklightAdvancedSearch.config = true to enable AND/OR/NOT parsing even in ordinary search, this is not on by default.

The advanced search form will be available in your app at /advanced

url_for(:controller => "advanced", :action => "index")

You can also send the advanced search form url parameters representing a search, to have the form add on additional ‘advanced’ criteria to the search. For example:

url_for( params.merge(:controller => "advanced", :action => "index")

If you do not have the default :controller/:action route enabled for your application, you may need to add a custom route to config/routes.rb. For example:

map.advanced 'advanced', :controller => 'advanced', :action => 'index'

By default there won’t be any links in your application to the search form. If you’ve heavily customized your app, you can put them wherever you want as above.

However, especially if your app isn’t much customized, the optional installer can write a localized Blacklight search form into your application with a ‘more options’ link to advanced. You may need to adjust your styles to make room for the new link, depending on what you’ve done with your app.

If your application uses a single Solr qt request handler for all its search fields, then this plugin may work well with no configuration. Nonetheless, configuration is available to change or improve behavior, or to use a separate Solr request handler for the advanced search plugin.

All plugin configuration mentioned below can be in any initializer in your app (any ruby file in config/initializers), although using the convention config/initializers/blacklight_advanced_search.rb may keep things clear.

The optional installer script can install a sample blacklight_advanced_search.rb for you which demonstrates various options.

If you turn on this feature with ‘BlacklightAdvancedSearch.config = true`, then the plugin will intercept queries entered in ordinary Blacklight search interface, and parse them for AND/OR/NOT (and parens), producing appropriate Solr query. This allows single-field boolean expressions to be entered in ordinary search, providing a consistent experience with advanced search.

When this feature is turned on, queries that don’t have any special operators (eg: AND, OR, NOT, parens) will still be passed to Solr much the same as they were before. But queries with special operators will have appropriate Solr queries generated for them, usually including nested “query” elements, to have the same meaning they would in advanced search.

Due to limitations of the logic, sometimes these generated Solr queries may not really be as simple as they could be, they may include a single nested query, which really doens’t need to be a nested query at all, although it will still work fine.

Your main blacklight search fields are generally defined in config/blacklight_config.rb, under “config” ( github.com/projectblacklight/blacklight/blob/master/config/initializers/blacklight_config.rb#L194 ). If there are particular search fields in your main blacklight config you want excluded from the advanced search form, you can set “:include_in_advanced_search => false”

All advanced search fields must share the same Solr request handler (“:qt”). As such, search fields that use a custom “:qt” parameter may not be re-used by the advanced search plugin. However, you may use a separate Solr request handler than the Blacklight default. If you would like the advanced search to use a different Solr request handler than your app’s default, set:

BlacklightAdvancedSearch.config[:qt]

to the name of the Solr request handler.

If you use a separate Solr request handler for advanced search, you must supply a completely separate list of search fields for the advanced search form. Each field is defined by a hash whose format is specified in Blacklight::SearchFields ( github.com/projectblacklight/blacklight/blob/master/lib/blacklight/search_fields.rb#L7 ).

BlacklightAdvancedSearch.config[:search_fields] = []
BlacklightAdvancedSearch.config[:search_fields] << {
  :key => 'title',
  :solr_local_parameters => {
    :qf => "title_t subtitle_t addl_titles_t title_unstem_search^1000" # see ( http://wiki.apache.org/solr/DisMaxQParserPlugin#qf_.28Query_Fields.29 )
    :pf => "title_t subtitle_t addl_titles_t title_unstem_search^1000" # see ( http://wiki.apache.org/solr/DisMaxQParserPlugin#pf_.28Phrase_Fields.29 )
  }
}

Additionally, to make your advanced search solr requests more concise, you are strongly encouraged to take advantage of the :local_solr_parameters option in your search field definition to use a solr parameter substitution with $variables.

BlacklightAdvancedSearch.config[:search_fields] << {
  :key => 'author'
  :solr_local_parameters => {
    :qf=>"$qf_author",
    :pf=>"$pf_author"
  }
}

Within your solrconfig.xml you may then provide the appropriate custom configuration.

<requestHandler name="advanced" class="solr.SearchHandler" >
  <lst name="defaults">
    <!-- ... -->
    <str name="qf_author">
      author_1xx_unstem_search^200
      author_7xx_unstem_search^50
      author_8xx_unstem_search^10
      author_1xx_search^20       vern_author_1xx_search^20
      author_7xx_search^5        vern_author_7xx_search^5
      author_8xx_search          vern_author_8xx_search
    </str>
    <str name="pf_author">
      author_1xx_unstem_search^5000
      author_7xx_unstem_search^3000
      author_1xx_search^500        vern_author_1xx_search^500
      author_7xx_search^300        vern_author_7xx_search^300
      author_8xx_unstem_search^250
      author_8xx_search^200        vern_author_8xx_search^200
    </str>
  </lst>
</requestHandler>

By default, the advanced search form will show as limits whatever facets are configured as default in your Solr request handler. To have the advanced search form request specific facets and/or specific facet parameters, you can set config.

BlacklightAdvancedSearch.config[:form_solr_parameters] = {
  "facet.field" => ["format", "language_facet"],
  "facet.limit" => -1, # return all facet values
  "facet.sort" => "index" # sort by byte order of values
}

config

Solr request handler to use for any search that includes advanced search criteria. Defaults to what the application has set as Blacklight.config

config

Key to use in application URLs to indicate advanced search is included in a query, defaults to “advanced”. URLs will have “&search_field=[url key]”.

config

Array of search field definitions to be used for advanced search. Each element in the array is a hash of the form required by Blacklight::SearchFields. If left blank, the plugin will use definitions from your main app Blacklight.config – only those which have no :qt set, and do not have :include_in_advanced_search => false.

config

A hash of solr parameters which will be included in Solr request sent before display of advanced search form. Can be used to set facet parameters for advanced search form display.

config

Set to ‘true’ to have AND/OR/NOT parsed even in ordinary ‘simple’ blacklight search, and converted to appropriate Solr query for that single field.

The code for mapping a user-entered query to a Solr query is called “nesting_parsing”, and maps to a ‘lucene’ query parser query, with nested ‘dismax’ query parser queries.

Some technical details can be found in the nesting_parsing README: [github.com/projectblacklight/blacklight_advanced_search/tree/master/lib/parsing_nesting]

You may also find the rspecs for parsing a user-entered query and converting it to Solr illumnating:

1. Converting user-entered query to Solr: [github.com/projectblacklight/blacklight_advanced_search/blob/master/spec/parsing_nesting/to_solr_spec.rb]

2. Parsing user-entered query to internal syntax tree: [github.com/projectblacklight/blacklight_advanced_search/blob/master/spec/parsing_nesting/build_tree_spec.rb]

Test coverage is provided with rspec, run all tests by running:

spec ./spec

• Alphabetical sorting of facet values returned by solr in count order (perhaps with limit).