=RSolr

A simple, extensible Ruby client for Apache Solr.

==Documentation
The code docs http://www.rubydoc.info/gems/rsolr

== Installation:
  gem install rsolr

== Example:
  require 'rsolr'

  # Direct connection
  solr = RSolr.connect :url => 'http://solrserver.com'

  # Connecting over a proxy server
  solr = RSolr.connect :url => 'http://solrserver.com', :proxy=>'http://user:pass@proxy.example.com:8080'

  # Using an alternate Faraday adapter
  solr = RSolr.connect :url => 'http://solrserver.com', :adapter => :em_http

  # Using a custom Faraday connection
  conn = Faraday.new do |faraday|
    faraday.response :logger                  # log requests to STDOUT
    faraday.adapter  Faraday.default_adapter  # make requests with Net::HTTP
  end
  solr = RSolr.connect conn, :url => 'http://solrserver.com'

  # send a request to /select
  response = solr.get 'select', :params => {:q => '*:*'}

  # send a request to /catalog
  response = solr.get 'catalog', :params => {:q => '*:*'}

When the Solr +:wt+ is +:ruby+, then the response will be a Hash. This Hash is the same object returned by Solr, but evaluated as Ruby. If the +:wt+ is not +:ruby+, then the response will be a String.

The response also exposes 2 attribute readers (for any +:wt+ value), +:request+ and +:response+. Both are Hash objects with symbolized keys.

The +:request+ attribute contains the original request context. You can use this for debugging or logging. Some of the keys this object contains are +:uri+, +:query+, +:method+ etc..

The +:response+ attribute contains the original response. This object contains the +:status+, +:body+ and +:headers+ keys.

== Request formats

By default, RSolr uses the Solr JSON command format for all requests.

  RSolr.connect :url => 'http://solrserver.com', update_format: :json # the default
  # or
  RSolr.connect :url => 'http://solrserver.com', update_format: :xml

== Timeouts
The read and connect timeout settings can be set when creating a new instance of RSolr, and will
be passed on to underlying Faraday instance:

  solr = RSolr.connect(:timeout => 120, :open_timeout => 120)

== Retry 503s
A 503 is usually a temporary error which RSolr may retry if requested. You may specify the number of retry attempts with the +:retry_503+ option.

Only requests which specify a Retry-After header will be retried, after waiting the indicated retry interval, otherwise RSolr will treat the request as a 500. You may specify a maximum Retry-After interval to wait with the +:retry_after_limit+ option (default: one second).
  solr = RSolr.connect(:retry_503 => 1, :retry_after_limit => 1)

For additional control, consider using a custom Faraday connection (see above) using its `retry` middleware.

== Querying
Use the #get / #post method to send search requests to the /select handler:
  response = solr.get 'select', :params => {
    :q=>'washington',
    :start=>0,
    :rows=>10
  }
  response["response"]["docs"].each{|doc| puts doc["id"] }

The +:params+ sent into the method are sent to Solr as-is, which is to say they are converted to Solr url style, but no special mapping is used.
When an array is used, multiple parameters *with the same name* are generated for the Solr query. Example:

  solr.get 'select', :params => {:q=>'roses', :fq=>['red', 'violet']}

The above statement generates this Solr query:

  select?q=roses&fq=red&fq=violet

===Pagination
To paginate through a set of Solr documents, use the paginate method:
  solr.paginate 1, 10, "select", :params => {:q => "test"}

The first argument is the current page, the second is how many documents to return for each page. In other words, "page" is the "start" Solr param and "per-page" is the "rows" Solr param.

The paginate method returns WillPaginate ready "docs" objects, so for example in a Rails application, paginating is as simple as:
  <%= will_paginate @solr_response["response"]["docs"] %>

===Method Missing
The +RSolr::Client+ class also uses +method_missing+ for setting the request handler/path:

  solr.paintings :params => {:q=>'roses', :fq=>['red', 'violet']}

This is sent to Solr as:
  paintings?q=roses&fq=red&fq=violet

This works with pagination as well:

  solr.paginate_paintings 1, 10, {:q=>'roses', :fq=>['red', 'violet']}

===Using POST for Search Queries
There may be cases where the query string is too long for a GET request. RSolr solves this issue by converting hash objects into form-encoded strings:
  response = solr.music :data => {:q => "*:*"}

The +:data+ hash is serialized as a form-encoded query string, and the correct content-type headers are sent along to Solr.

===Sending HEAD Requests
There may be cases where you'd like to send a HEAD request to Solr:
  solr.head("admin/ping").response[:status] == 200

==Sending HTTP Headers
Solr responds to the request headers listed here: http://wiki.apache.org/solr/SolrAndHTTPCaches
To send header information to Solr using RSolr, just use the +:headers+ option:
  response = solr.head "admin/ping", :headers => {"Cache-Control" => "If-None-Match"}

===Building a Request
+RSolr::Client+ provides a method for building a request context, which can be useful for debugging or logging etc.:
  request_context = solr.build_request "select", :data => {:q => "*:*"}, :method => :post, :headers => {}

To build a paginated request use build_paginated_request:
  request_context = solr.build_paginated_request 1, 10, "select", ...

== Updating Solr
Updating is done using native Ruby objects. Hashes are used for single documents and arrays are used for a collection of documents (hashes). These objects get turned into simple XML "messages". Raw XML strings can also be used.

Single document via #add
  solr.add :id=>1, :price=>1.00

Multiple documents via #add
  documents = [{:id=>1, :price=>1.00}, {:id=>2, :price=>10.50}]
  solr.add documents

The optional +:add_attributes+ hash can also be used to set Solr "add" document attributes:
  solr.add documents, :add_attributes => {:commitWithin => 10}

Raw commands via  #update
  solr.update data: '<commit/>', headers: { 'Content-Type' => 'text/xml' }
  solr.update data: { optimize: true }.to_json, headers: { 'Content-Type' => 'application/json' }

When adding, you can also supply "add" xml element attributes and/or a block for manipulating other "add" related elements (docs and fields) by calling the +xml+ method directly:

  doc = {:id=>1, :price=>1.00}
  add_attributes = {:allowDups=>false, :commitWithin=>10}
  add_xml = solr.xml.add(doc, add_attributes) do |doc|
    # boost each document
    doc.attrs[:boost] = 1.5
    # boost the price field:
    doc.field_by_name(:price).attrs[:boost] = 2.0
  end

Now the "add_xml" object can be sent to Solr like:
  solr.update :data => add_xml

===Deleting
Delete by id
  solr.delete_by_id 1
or an array of ids
  solr.delete_by_id [1, 2, 3, 4]

Delete by query:
  solr.delete_by_query 'price:1.00'
Delete by array of queries
  solr.delete_by_query ['price:1.00', 'price:10.00']

===Commit / Optimize
  solr.commit, :commit_attributes => {}
  solr.optimize, :optimize_attributes => {}

== Response Formats
The default response format is Ruby. When the +:wt+ param is set to +:ruby+, the response is eval'd resulting in a Hash. You can get a raw response by setting the +:wt+ to +"ruby"+ - notice, the string -- not a symbol. RSolr will eval the Ruby string ONLY if the :wt value is :ruby. All other response formats are available as expected, +:wt=>'xml'+ etc..

===Evaluated Ruby:
  solr.get 'select', :params => {:wt => :ruby} # notice :ruby is a Symbol
===Raw Ruby:
  solr.get 'select', :params => {:wt => 'ruby'} # notice 'ruby' is a String
===XML:
  solr.get 'select', :params => {:wt => :xml}
===JSON (default):
  solr.get 'select', :params => {:wt => :json}

==Related Resources & Projects
* {RSolr Google Group}[http://groups.google.com/group/rsolr] -- The RSolr discussion group
* {rsolr-ext}[http://github.com/mwmitchell/rsolr-ext] -- An extension kit for RSolr
* {rsolr-direct}[http://github.com/mwmitchell/rsolr-direct] -- JRuby direct connection for RSolr
* {rsolr-nokogiri}[http://github.com/mwmitchell/rsolr-nokogiri] -- Gives RSolr Nokogiri for XML generation.
* {SunSpot}[http://github.com/sunspot/sunspot] -- An awesome Solr DSL, built with RSolr
* {Blacklight}[http://blacklightopac.org] -- A "next generation" Library OPAC, built with RSolr
* {java_bin}[http://github.com/kennyj/java_bin] -- Provides javabin/binary parsing for RSolr
* {Solr}[http://lucene.apache.org/solr/] -- The Apache Solr project
* {solr-ruby}[http://wiki.apache.org/solr/solr-ruby] -- The original Solr Ruby Gem!

== Note on Patches/Pull Requests
* Fork the project.
* Make your feature addition or bug fix.
* Add tests for it. This is important so I don't break it in a future version unintentionally.
* Commit, do not mess with rakefile, version, or history
  (if you want to have your own version, that is fine but bump version in a commit by itself I can ignore when I pull)
* Send me a pull request. Bonus points for topic branches.

==Contributors
* Nathan Witmer
* Magnus Bergmark
* shima
* Randy Souza
* Mat Brown
* Jeremy Hinegardner
* Denis Goeury
* shairon toledo
* Rob Di Marco
* Peter Kieltyka
* Mike Perham
* Lucas Souza
* Dmitry Lihachev
* Antoine Latter
* Naomi Dushay

==Author

Matt Mitchell <mailto:goodieboy@gmail.com>

==Copyright

Copyright (c) 2008-2010 Matt Mitchell. See LICENSE for details.