Class: SRU::Client

Inherits:
Object
  • Object
show all
Defined in:
lib/sru/client.rb

Overview

A client for issuing requests to a particular SRU server. SRU is a RESTlike information retrieval protocol detailed at www.loc.gov/standards/sru/

require 'sru'

client = SRU::Client.new 'http://sru.example.com'

# fetch a SRU::ExplainResponse object from the server
explain = client.explain

# issue a search and get back a SRU::SearchRetrieveResponse object 
# which serves as an iterator 
records = client.search_retrieve 'rosetta stone', :maximumRecords => 5
records.each {|record| puts record}

# issue a scan request and print out each term
client.scan('king tut', :maximumTerms => 12).each {|term| puts term}

Constant Summary collapse

DEFAULT_SRU_VERSION = 
'1.2'

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(base, options = {}) ⇒ Client

creates a client object which will automatically perform an explain request to determine the version to be used in subsequent requests.



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# File 'lib/sru/client.rb', line 35

def initialize(base,options={})
  @server = URI.parse base
  @parser = options.fetch(:parser, 'rexml')
  case @parser
  when 'libxml'
    begin
      require 'rubygems'
      require 'libxml'
    rescue
      raise SRU::Exception, "unknown parser: #{@parser}", caller 
    end
  when 'rexml'
    require 'rexml/document'
    require 'rexml/xpath'
  else
    raise SRU::Exception, "unknown parser: #{@parser}", caller
  end
    
  # stash this away for future requests
  @version = self.explain.version
end

Instance Attribute Details

#version ⇒ Object

Returns the value of attribute version.



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# File 'lib/sru/client.rb', line 30

def version
  @version
end

Instance Method Details

#explain ⇒ Object

Send an explain request to the SRU server and return a SRU::ExplainResponse object.

client = SRU::Client.new ‘sru.example.com’ explain = client.explain



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# File 'lib/sru/client.rb', line 64

def explain
  doc = get_doc(:operation => 'explain')
  return ExplainResponse.new(doc, @parser)
end

#scan(clause, options = {}) ⇒ Object

Send a scan request to the SRU server and return a SRU::ScanResponse object. You must supply the first parameter which is the searchClause. Other SRU options can be sent in a hash as the seond argument.

scan_response = client.scan 'title', :maximumTerms => 5



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# File 'lib/sru/client.rb', line 94

def scan(clause, options={})
  options[:scanClause] = clause
  options[:operation] = 'scan'
  options[:maximumTerms] = 5 unless options.has_key? :maximumTerms
  doc = get_doc(options)
  return ScanResponse.new(doc, @parser)
end

#search_retrieve(query, options = {}) ⇒ Object

Send a searchRetrieve request to the SRU server and return a SRU::SearchResponse object. The first argument is the required query option. Any remaining searchRetrieve options can be passed as an optional second argument. 

client = SRU::Client.new 'http://example.com/sru'
response = client.search_retrieve 'mark twain', maximumRecords => 1



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# File 'lib/sru/client.rb', line 78

def search_retrieve(query, options={})
  options[:query] = query
  options[:operation] = 'searchRetrieve'
  options[:maximumRecords] = 10 unless options.has_key? :maximumRecords
  options[:recordSchema] = 'dc' unless options.has_key? :recordSchema
  doc = get_doc(options)
  return SearchResponse.new(doc, @parser)
end