# BentoSearch [![Build Status](https://secure.travis-ci.org/jrochkind/bento_search.png)](http://travis-ci.org/jrochkind/bento_search) (Fairly robust and stable at this point, but still pre-1.0 release, may be some breaking api changes before 1.0, but probably not too many, it's looking pretty good). bento_search provides an abstraction/normalization layer for querying and displaying results from external search engines, in Ruby on Rails. Requires Rails3 and tested only under ruby 1.9.3. ### Goals: To help you * **Get up and running as quickly as possible** with searching and displaying results from a third-party service. Solutions to idiosyncracies and undocumented workarounds are encoded in a shared codebase, which abstracts everything to a good, simple code API giving you building blocks to focus on your needs, not the search service's problems. * Let you switch out one search service for another in an already built application with as little code rewriting as possible. **Avoid vendor lock-in**. * Give you the harness to **write adapters for new search services**, without having to rewrite common general functionality, just focus on the interface with the new API you want to support. bento_search is focused on use cases for academic libraries, which is mainly evidenced by the search engine adapters currently included, and by the generalized domain models including fields that matter in our domain (issn, vol/issue/page, etc), and some targetted functionality (OpenURL generation). But it ought to be useful for more general basic use cases too (we include a google site search adapter for instance). Adapters currently included in bento_search * Google Books (requires free api key) * Scopus (requires license) * Serial Solution Summon (requires license) * Ex Libris Primo (requires license) * EBSCO Discovery Service (requires license) * EBSCOHost 'traditional' API (requires license) * WorldCat Search (requires OCLC membership to get api key) * Google Site Search (requires sign-up for more than 100 searches/day) ### Scope of functionality bento_search could be considered building blocks for a type of 'federated search' functionality, but it does not and will never support merging results from multiple engines into one result set. It is meant to support displaying the first few results from multiple engines on one page, "bento box" style (as named by Tito Sierra@NCSU), as well as more expanded single-search-on-a-page uses. * bento_search provides abstract functionality for pagination, sorting, and single-field-specified queries. Faceting, generalized limiting, and 'advanced' multi-field searches are not yet supported, but possibly will be built out in the future. Not all search engine adapters support all features. Some engines offer engine-specific features, such as limiting. Search engine adapters can declare search fields and sort options with 'semantics', so you can for instance search or sort by 'title' across search engines without regard to internal engine-specific field names. bento_search is designed to allow code to be written agnostic of the search provider, so you can switch out the search provider. See code-level api documentation for more details, especially at BentoSearch::SearchEngine. http://rubydoc.info/gems/bento_search/frames/ An example app using BentoSearch and showing it's features is available at http://github.com/jrochkind/sample_megasearch There is a short screencast showing that sample app in action here: http://screencast.com/t/JLS0lclrBZU ## Usage Examples ### Instantiate an engine, and search When you instantiate an engine, you can provide configuration keys. There are a few standard keys (see BentoSearch::SearchEngine), and others that may be engine-specific. Some engine-specific keys (such as api auth keys) may be required for certain engines. ~~~~ruby engine = BentoSearch::GoogleBooksEngine.new(:api_key => "my_gbs_api_key") results = engine.search("a query") ~~~~ `results` are a BentoSearch::Results object, which acts like an array of BentoSearch::Item objects, along with some meta-information about the search itself (pagination keys, etc). BentoSearch::Results and Item fields are standardized accross engines. BentoSearch::Items provide semantic values (title, author, etc.), as available from the particular engine. To see which engines come bundled with BentoSearch, and any special engine-specific instructions, look at BentoSearch source in `./app/search_engines` ### Register engines in global configuration It can be convenient to register an engine in global configuration, and is required for certain functionality (like out-of-the-box AJAX loading). In an initializer in your app, like say `./config/initializers/bento_search.rb`: ~~~~ruby BentoSearch.register_engine("gbs") do |conf| conf.engine = "BentoSearch::GoogleBooksEngine" conf.api_key = "my_google_api_key" # any other configuration end ~~~~ Then you can refer to it, for instance in a controller, by the id you registered: ~~~~ruby @results = BentoSearch.get_engine("gbs").search("my query") ~~~~ ### Display results You can of course write your own code to display a BentoSearch::Results object however you like. But BentoSearch comes with a helper method for displaying a list of BentoSearch::Results in a standard way, using the bento_search helper method. ~~~~ruby <%= bento_search @results %> ~~~~ See also the [Customizing Results Display wiki page](https://github.com/jrochkind/bento_search/wiki/Customizing-Results-Display). ### Fielded searching. You can search by an internal engine-specific field name: ~~~~ruby google_books_engine.search("smith", :search_field => "inauthor") ~~~~ Or, if the engine provides it, you can search by normalized semantic search field type names: ~~~~ruby google_books_engine.search("smith", :semantic_search_field => :title) ~~~~ You can find out what fields a particular engine supports. ~~~~ruby google_books_engine.search_keys # => internal keys google_books_engine.semantic_search_keys ~~~~ A helper method for generating an html select of search field options is available in `bento_field_hash_for`, check it out. You can also provide all arguments in a single hash when it's convenient to do so: ~~~~ruby google_books_engine.search(:query => "smith", :search_field => "inauthor") ~~~~ Search fields that are not recognized (semantic or internal) will normally be ignored, but set `:unrecognized_search_field => :raise` in configuration or search arg to get an ArgumentError instead. ### Sorting An engine advertises what sort types it supports: ~~~~ruby google_books_engine.sort_keys ~~~~ An array of sort identifiers, where possible chosen from a standard list of semantics. (See list in `./config/i18n/en.yml`, `bento_search.sort_keys`). ~~~~ruby google_books_engine.search("my query", :sort => "date_desc") ~~~~ For help creating your UI, you can use built-in helper method, perhaps with Rails helper options_for_select: ~~~~ruby <%= options_for_select( bento_sort_hash_for(engine), params[:sort] ) %> ~~~~ ### Pagination You can tell the search engine how many items you want per-page, and use _either_ `:start` (0-based item offset) or `:page` (1-based page offset) keys to paginate into the results. ~~~~ruby results = google_books_engine.search("my query", :per_page => 20, :start => 40) results = google_books_engine.search("my query", :per_page => 20, :page => 2) # means same as above ~~~~ An engine instance advertises it's maximum per-page values. ~~~~ruby google_books_engine.max_per_page ~~~~ bento_search fixes the default per_page at 10. For help creating your UI, you can ask a BentoSearch::Results for `results.pagination`, which returns a BentoSearch::Results::Pagination object which should be suitable for passing to [kaminari](https://github.com/amatsuda/kaminari) `paginate`, or else have convenient methods for roll your own pagination UI. Kaminari's paginate method: ~~~~ruby <%= paginate results.pagination %> ~~~~ ### Concurrent searching If you're going to search 2 or more search engines at once, you'll want to execute those searches concurrently. For instance, if GoogleBooks results take 2 second to come in, and Scopus results take 3 seconds -- you don't want to first wait the 2 second then wait the 3 seconds for a total of 5 -- you instead want to execute concurrently in seperate threads, so the total wait time is the slowest engine, not the sum of the engines. You can write your own logic using ruby threads to do this, but BentoSearch provides a multi-searching helper using [Celluloid](https://github.com/celluloid/celluloid) to help you do this easily. Say, in a controller: ~~~~ruby # constructor takes id's registered with BentoSearch.register_engine searcher = BentoSearch::MultiSearcher.new(:gbs, :scopus, :summon) # Call 'search' with any parameters you would give to an_engine.search searcher.search("my query", :semantic_search_field => :author, :sort => "title") # At this point, all searches are executing asynchronously in seperate threads. # To get the results, blocking until all complete: @results = searcher.results # @results will be a hash, keyed by registered engine id, values # are BentoSearch::Results ~~~~ Even if you are only searching one engine, this may be useful to have the search execute in a seperate thread, so you can continue doing other work in the main thread (like search a local store of some kind outside of bento_search) You will need to add the 'celluloid' gem to your app to use this feature, BentoSearch doesn't automatically include the celluloid dependency. Note that Celluloid uses multi-threading in such a way that you might need to turn Rails config.cache_classes=true even in development. For more info, see BentoSearch::MultiSearcher. ### Delayed results loading via AJAX (actually more like AJAHtml) BentoSearch provides some basic support for initially displaying a placeholder progress spinner, and having Javascript call back to get the actual results. It's not a panacea for pathologically slow search results, and can be tricky for results that need access controls. But it can be useful in some situations, both for automatic on-page-load ajax loading, and triggered ajax loading. See the [wiki page](https://github.com/jrochkind/bento_search/wiki/AJAX-results-loading) for more info. ### Item Decorators, and Links You can configure Decorators, in the form of plain old ruby modules, to be applied to BentoSearch::Items, on an engine-by-engine basis. These can modify, add, or remove Item data, as well as over-ride some presentational methods. One common use for these Decorators is changing, adding, or removing links associated with an item. For instance, to link to your local OpenURL link resolver. BentoSearch::Items can have a main link associated with them (generally hyperlinked from title), as well as a list of additional links. Most engines do not provide additional links by default, custom local Decorators would be used to add them. See wiki for more info on decorators, and BentoSearch::Link for fields. ## OpenURL and metadata Academic library uses often need openurl links from scholarly citations. One of the design goals of bento_search is to produce standardized normalized BentoSearch::ResultItem models, with sufficient semantics for translation to other formats. See ResultItem#to_openurl_kev (string URL query encoding of OpenURL), and ResultItem#to_openurl (a [ruby OpenURL gem](https://github.com/openurl/openurl) object). Quality may vary, depending on how well the particular engine adapter captures semantics, especially the format/type of results (See bento_search's internal format/type vocabulary documented at ResultItem#format). As well as how well the #to_openurl routine handles all edge cases (OpenURL can be weird). As edge cases are discovered, they can be solved. See `./app/item_decorators/bento_search/openurl_add_other_link.rb` for an example of using item decorators to add a link to your openurl resover to an item when displayed. ## Planned Features I am trying to keep BentoSearch as simple as it can be to conveniently meet actual use cases. Trying to avoid premature over-engineering, and pave the cowpaths as needed. Probably: * Support for display facets for engines that support such, as well as search with limits from controlled vocabulary (ie, selected facet, but also may be supported by some engines that do not support facetting). * Support for multi-field, multi-entry-box 'advanced search' UI's, in a normalized cross-engine way. Other needs or suggestions? ## Developing BentoSearch is fairly well covered by automated tests. We simply use Test::Unit. Run tests with `rake test`. The testing environment was generated with `rails plugin new`, and includes a dummy app used when testing at `./test/dummy`. For integration tests against live external search API's, we use the awesome [VCR](https://github.com/myronmarston/vcr) gem to cache responses. To write your own Test::Unit tests using VCR, take note of the `test_with_cassette` method provided in `./test/support/test_with_cassette.rb`. Also note use of VCR.filter_sensitive_data to make sure your API keys do not get saved in cached response in the repo, while still allowing tests to be run against cached responses even for engines that require auth. To re-generate cached responses, delete the relevant files in `./test/vcr_cassettes` and re-run tests. You may have to set an ENV variable with your own API keys to re-run tests without cached response like this. Also note `BentoSearch::MockEngine`, a simple mock/dummy SearchEngine implementation that can be used in other tests, including in client software where convenient. Pull requests welcome. Pull requests with additional search engine implementations welcome. See more info on writing a BentoSearch::SearchEngine in the inline docs in that file.