Module: ActiveFedora::FinderMethods

Included in:
Relation
Defined in:
lib/active_fedora/relation/finder_methods.rb

Instance Method Summary collapse

Instance Method Details

#exists?(conditions) ⇒ Boolean

Returns true if object having the id or matching the conditions exists in the repository Returns false if param is false (or nil) @param[ActiveFedora::Base, String, Hash] object, id or hash of conditions @return

Returns:

  • (Boolean) 


85
86
87
88
89
90
91
92
93
94
95
96
97
98
 
# File 'lib/active_fedora/relation/finder_methods.rb', line 85

def exists?(conditions)
  conditions = conditions.id if Base === conditions
  return false unless conditions
  case conditions
  when Hash
    search_with_conditions(conditions, rows: 1).present?
  when String
    find(conditions).present?
  else
    raise ArgumentError, "`conditions' argument must be ActiveFedora::Base, String, or Hash: #{conditions.inspect}"
  end
rescue ActiveFedora::ObjectNotFoundError, Ldp::Gone
  false
end

#find(*args) ⇒ Object

Returns an Array of objects of the Class that find is being called on

@param args either an id or a hash of conditions

Parameters:

  • args (Hash) —

    a customizable set of options

Options Hash (*args):

  • :rows (Integer) —

    when :all is passed, the maximum number of rows to load from solr

  • :cast (Boolean) —

    when true, examine the model and cast it to the first known cModel



36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
 
# File 'lib/active_fedora/relation/finder_methods.rb', line 36

def find(*args)
  return to_a.find { |*block_args| yield(*block_args) } if block_given?
  options = args.extract_options!
  options = options.dup
  cast = if @klass == ActiveFedora::Base && !options.key?(:cast)
           true
         else
           options.delete(:cast)
         end
  if options[:sort]
    # Deprecate sort sometime?
    sort = options.delete(:sort)
    options[:order] ||= sort if sort.present?
  end

  if options.present?
    options = args.first unless args.empty?
    Deprecation.warn(ActiveFedora::Base, "Calling .find with a hash has been deprecated and will not be allowed in active-fedora 10.0. Use .where instead")
    options = { conditions: options }
    apply_finder_options(options)
  else
    raise ArgumentError, "#{self}.find() expects an id. You provided `#{args.inspect}'" unless args.is_a? Array
    find_with_ids(args, cast)
  end
end

#find_each(conditions = {}, opts = {}) ⇒ Object

Yields the found ActiveFedora::Base object to the passed block

Parameters:

  • conditions (Hash) (defaults to: {}) —

    the conditions for the solr search to match

  • opts (Hash) (defaults to: {})

Options Hash (opts):

  • :cast (Boolean) — default: true —

    when true, examine the model and cast it to the first known cModel



139
140
141
142
143
144
145
146
147
148
149
150
 
# File 'lib/active_fedora/relation/finder_methods.rb', line 139

def find_each(conditions = {}, opts = {})
  cast = opts.delete(:cast)
  search_in_batches(conditions, opts.merge(fl: ActiveFedora.id_field)) do |group|
    group.each do |hit|
      begin
        yield(load_from_fedora(hit[ActiveFedora.id_field], cast))
      rescue Ldp::Gone
        ActiveFedora::Base.logger.error "Although #{hit[ActiveFedora.id_field]} was found in Solr, it doesn't seem to exist in Fedora. The index is out of synch." if ActiveFedora::Base.logger
      end
    end
  end
end

#find_in_batches(*args) ⇒ Object

Deprecated. 


186
187
188
189
 
# File 'lib/active_fedora/relation/finder_methods.rb', line 186

def find_in_batches(*args)
  Deprecation.warn(ActiveFedora::Base, '.find_in_batches is deprecated and will be removed in active-fedora 10.0; use .search_in_batches instead')
  search_in_batches(*args)
end

#find_one(id, cast = nil) ⇒ Object

Retrieve the Fedora object with the given id, explore the returned object Raises a ObjectNotFoundError if the object is not found.

Examples:

because the object hydra:dataset1 asserts it is a Dataset (hasModel fedora.info/definitions/v4/model#Dataset), return a Dataset object (not a Book).

Book.find_one("hydra:dataset1")

Parameters:

  • id (String) —

    of the object to load

  • cast (Boolean) (defaults to: nil) —

    when true, cast the found object to the class of the first known model defined in it’s RELS-EXT



198
199
200
201
202
203
204
205
206
 
# File 'lib/active_fedora/relation/finder_methods.rb', line 198

def find_one(id, cast = nil)
  if where_values.empty?
    load_from_fedora(id, cast)
  else
    conditions = where_values + [ActiveFedora::SolrQueryBuilder.construct_query(ActiveFedora.id_field => id)]
    query = conditions.join(" AND ".freeze)
    to_enum(:find_each, query, {}).to_a.first
  end
end

#find_take ⇒ Object 



73
74
75
76
77
78
79
 
# File 'lib/active_fedora/relation/finder_methods.rb', line 73

def find_take
  if loaded?
    @records.first
  else
    @take ||= limit(1).to_a.first
  end
end

#find_with_conditions(*args) ⇒ Object

Deprecated. 


129
130
131
132
 
# File 'lib/active_fedora/relation/finder_methods.rb', line 129

def find_with_conditions(*args)
  Deprecation.warn(ActiveFedora::Base, '.find_with_conditions is deprecated and will be removed in active-fedora 10.0; use .search_with_conditions instead')
  search_with_conditions(*args)
end

#first ⇒ Object

Returns the first records that was found.

Examples:

Person.where(name_t: 'Jones').first
  => #<Person @id="foo:123" @name='Jones' ... >


8
9
10
11
12
13
14
 
# File 'lib/active_fedora/relation/finder_methods.rb', line 8

def first
  if loaded?
    @records.first
  else
    @first ||= limit(1).to_a[0]
  end
end

#last ⇒ Object

Returns the last record sorted by id. ID was chosen because this mimics how ActiveRecord would achieve the same behavior.

Examples:

Person.where(name_t: 'Jones').last
  => #<Person @id="foo:123" @name='Jones' ... >


22
23
24
25
26
27
28
 
# File 'lib/active_fedora/relation/finder_methods.rb', line 22

def last
  if loaded?
    @records.last
  else
    @last ||= order('id desc').limit(1).to_a[0]
  end
end

#search_by_id(id, opts = {}) ⇒ Object

Returns a single solr hit matching the given id

Parameters:

  • id (String) —

    document id

  • opts (Hash) (defaults to: {}) 


117
118
119
120
121
122
123
124
125
126
 
# File 'lib/active_fedora/relation/finder_methods.rb', line 117

def search_by_id(id, opts = {})
  opts[:rows] = 1
  result = search_with_conditions({ id: id }, opts)

  if result.empty?
    raise ActiveFedora::ObjectNotFoundError, "Object #{id} not found in solr"
  end

  result.first
end

#search_in_batches(conditions, opts = {}) ⇒ Object

Yields each batch of solr records that was found by the find options as an array. The size of each batch is set by the :batch_size option; the default is 1000.

Returns a solr result matching the supplied conditions @param conditions solr conditions to match @param options

Examples:

Person.search_in_batches('age_t'=>'21', {:batch_size=>50}) do |group|
group.each { |person| puts person['name_t'] }
end

Parameters:

  • opts (Hash) (defaults to: {}) —

    a customizable set of options

Options Hash (opts):

  • :sort (Array) —

    a list of fields to sort by

  • :rows (Array) —

    number of rows to return



166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
 
# File 'lib/active_fedora/relation/finder_methods.rb', line 166

def search_in_batches(conditions, opts = {})
  opts[:q] = create_query(conditions)
  opts[:qt] = @klass.solr_query_handler
  # set default sort to created date ascending
  opts[:sort] = @klass.default_sort_params unless opts[:sort].present?

  batch_size = opts.delete(:batch_size) || 1000
  select_path = ActiveFedora::SolrService.select_path

  counter = 0
  loop do
    counter += 1
    response = ActiveFedora::SolrService.instance.conn.paginate counter, batch_size, select_path, params: opts
    docs = response["response"]["docs"]
    yield docs
    break unless docs.has_next?
  end
end

#search_with_conditions(conditions, opts = {}) ⇒ Object

Returns a solr result matching the supplied conditions @param conditions can either be specified as a string, or hash representing the query part of an solr statement. If a hash is provided, this method will generate conditions based simple equality combined using the boolean AND operator.

Parameters:

  • options (Hash)
  • opts (Hash) (defaults to: {}) —

    a customizable set of options

Options Hash (opts):

  • :sort (Array) —

    a list of fields to sort by

  • :rows (Array) —

    number of rows to return



108
109
110
111
112
 
# File 'lib/active_fedora/relation/finder_methods.rb', line 108

def search_with_conditions(conditions, opts = {})
  # set default sort to created date ascending
  opts[:sort] = @klass.default_sort_params unless opts.include?(:sort)
  SolrService.query(create_query(conditions), opts)
end

#take(limit = nil) ⇒ Object

Gives a record (or N records if a parameter is supplied) without any implied order. The order will depend on the database implementation. If an order is supplied it will be respected.

Person.take # returns an object fetched by SELECT * FROM people LIMIT 1
Person.take(5) # returns 5 objects fetched by SELECT * FROM people LIMIT 5
Person.where(["name LIKE '%?'", name]).take



69
70
71
 
# File 'lib/active_fedora/relation/finder_methods.rb', line 69

def take(limit = nil)
  limit ? limit(limit).to_a : find_take
end