Class: MarkLogic::Cursor

Inherits:
Object
  • Object
show all
Includes:
Enumerable
Defined in:
lib/marklogic/cursor.rb

Constant Summary collapse

DEFAULT_PAGE_LENGTH = 
25

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(collection, options = {}) ⇒ Cursor

Returns a new instance of Cursor.



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# File 'lib/marklogic/cursor.rb', line 10

def initialize(collection, options = {})
  @options = options || {}
  @query = options.delete(:query)
  @collection = collection
  @transformer = options.delete(:transformer)
  @fields = options.delete(:fields)
  @fields = convert_fields_for_query(@fields) if @fields
  @connection = @collection.database.connection
  @limit = options.delete(:limit)
  @cache = []
  @query_run = false
  @visited = 0
end

Instance Attribute Details

#queries ⇒ Object

Returns the value of attribute queries.



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# File 'lib/marklogic/cursor.rb', line 6

def queries
  @queries
end

Instance Method Details

#convert_fields_for_query(fields) ⇒ Object 



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# File 'lib/marklogic/cursor.rb', line 70

def convert_fields_for_query(fields)
  case fields
    when String, Symbol
      [ fields ]
    when Array
      return nil if fields.length.zero?
      fields
    when Hash
      return fields.keys
  end
end

#count ⇒ Object

Raises:

  • (Exception) 


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# File 'lib/marklogic/cursor.rb', line 24

def count
  col_name = collection.nil? ? "" : %Q{"#{collection.collection}"}
  query_to_run = %Q{xdmp:estimate(cts:search(fn:collection(#{col_name}), #{query.to_xqy}, ("unfiltered")))}
  response = @connection.run_query(query_to_run, "xquery")
  raise Exception.new("Invalid response: #{response.code.to_i}: #{response.body}") if (response.code.to_i != 200)
  response.body.to_i
end

#each(&block) ⇒ Object 



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# File 'lib/marklogic/cursor.rb', line 82

def each(&block)
  while doc = self.next
    yield doc
  end
end

#next ⇒ Object Also known as: next_document 



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# File 'lib/marklogic/cursor.rb', line 37

def next
  refresh unless @query_run

  return nil if @visited == @limit

  if @cache.length == 0
    if page < total_pages
      self.page = page + 1
      refresh
    end

    if @cache.length == 0
      return nil
    end
  end

  @visited = @visited + 1
  doc = @cache.shift

  # TODO: Move this server side
  if @fields
    @fields << :_id unless @fields.include?(:_id) || @fields.include?('_id')
    doc = @fields.each_with_object(doc.class.new) { |key, result| result[key] = doc[key.to_s] if doc.has_key?(key.to_s) }
  end

  if @transformer.nil?
    doc
  else
    @transformer.call(doc) if doc
  end
end

#paged_results ⇒ Object 



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# File 'lib/marklogic/cursor.rb', line 32

def paged_results
  refresh unless @query_run
  @cache
end

#rewind! ⇒ Object 



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# File 'lib/marklogic/cursor.rb', line 92

def rewind!
  self.page = 1
  @query_run = false
  @visited = 0
end

#to_a ⇒ Object 



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# File 'lib/marklogic/cursor.rb', line 88

def to_a
  super
end