Class: Mongoid::Contextual::None

Inherits:
Object
  • Object
show all
Includes:
Enumerable, Aggregable::None, Queryable
Defined in:
lib/mongoid/contextual/none.rb

Instance Attribute Summary collapse

Attributes included from Queryable

#collection, #collection The collection to query against., #criteria The criteria for the context., #klass The klass for the criteria.

Instance Method Summary collapse

Methods included from Queryable

#blank?

Methods included from Aggregable::None

#aggregates, #avg, #min

Constructor Details

#initialize(criteria) ⇒ None

Create the new null context.

Examples:

Create the new context.

Null.new(criteria)

Parameters:



128
129
130
 
# File 'lib/mongoid/contextual/none.rb', line 128

def initialize(criteria)
  @criteria, @klass = criteria, criteria.klass
end

Instance Attribute Details

#criteria ⇒ Object (readonly)

Returns the value of attribute criteria.



14
15
16
 
# File 'lib/mongoid/contextual/none.rb', line 14

def criteria
  @criteria
end

#klass ⇒ Object (readonly)

Returns the value of attribute klass.



14
15
16
 
# File 'lib/mongoid/contextual/none.rb', line 14

def klass
  @klass
end

Instance Method Details

#==(other) ⇒ true | false

Check if the context is equal to the other object.

Examples:

Check equality.

context == []

Parameters:

  • other (Array) —

    The other array.

Returns:

  • (true | false) —

    If the objects are equal.



44
45
46
 
# File 'lib/mongoid/contextual/none.rb', line 44

def ==(other)
  other.is_a?(None)
end

#distinct(_field) ⇒ Array

Get the distinct field values in null context.

Examples:

Get the distinct values in null context.

context.distinct(:name)

Parameters:

  • _field (String | Symbol) —

    The name of the field.

Returns:

  • (Array) —

    An empty Array.



56
57
58
 
# File 'lib/mongoid/contextual/none.rb', line 56

def distinct(_field)
  []
end

#each ⇒ Enumerator

Iterate over the null context. There are no documents to iterate over in this case.

Examples:

Iterate over the null context.

context.each do |doc|
  puts doc.name
end

Returns:

  • (Enumerator) —

    The enumerator.



69
70
71
72
73
74
75
76
 
# File 'lib/mongoid/contextual/none.rb', line 69

def each
  if block_given?
    [].each { |doc| yield(doc) }
    self
  else
    to_enum
  end
end

#exists? ⇒ false

Do any documents exist for the context.

Examples:

Do any documents exist in the null context.

context.exists?

Returns:

  • (false) —

    Always false.



84
 
# File 'lib/mongoid/contextual/none.rb', line 84

def exists?; false; end

#first(limit = nil) ⇒ nil Also known as: find_first, one

Always returns nil.

Examples:

Get the first document in null context.

context.first

Parameters:

  • limit (Integer) (defaults to: nil) —

    The number of documents to return.

Returns:

  • (nil) —

    Always nil.



140
141
142
 
# File 'lib/mongoid/contextual/none.rb', line 140

def first(limit = nil)
  [] unless limit.nil?
end

#last(limit = nil) ⇒ nil

Always returns nil.

Examples:

Get the last document in null context.

context.last

Parameters:

  • limit (Integer) (defaults to: nil) —

    The number of documents to return.

Returns:

  • (nil) —

    Always nil.



152
153
154
 
# File 'lib/mongoid/contextual/none.rb', line 152

def last(limit = nil)
  [] unless limit.nil?
end

#length ⇒ Integer Also known as: size

Always returns zero.

Examples:

Get the length of null context.

context.length

Returns:

  • (Integer) —

    Always zero.



184
185
186
 
# File 'lib/mongoid/contextual/none.rb', line 184

def length
  Mongoid.broken_aggregables ? 0 : entries.length
end

#new_sum ⇒ Object 



16
 
# File 'lib/mongoid/contextual/none.rb', line 16

alias :new_sum :sum

#old_sum ⇒ Object 



9
 
# File 'lib/mongoid/contextual/none.rb', line 9

alias :old_sum :sum

#pick(*_fields) ⇒ nil

Pick the field values in null context.

Examples:

Get the value for null context.

context.pick(:name)

Parameters:

  • *_fields (String | Symbol) —

    Field or fields to pick.

Returns:

  • (nil) —

    Always reeturn nil.



106
107
108
 
# File 'lib/mongoid/contextual/none.rb', line 106

def pick(*_fields)
  nil
end

#pluck(*_fields) ⇒ Array

Pluck the field values in null context.

Examples:

Get the values for null context.

context.pluck(:name)

Parameters:

  • *_fields (String | Symbol) —

    Field(s) to pluck.

Returns:

  • (Array) —

    An empty Array.



94
95
96
 
# File 'lib/mongoid/contextual/none.rb', line 94

def pluck(*_fields)
  []
end

#sum(_field = nil) ⇒ Integer | Symbol

Get the sum in the null context.

Examples:

Get the sum of null context.

context.sum(_field)

Parameters:

  • _field (Symbol) (defaults to: nil) —

    The field to sum.

Returns:

  • (Integer | Symbol) —

    If Mongoid.broken_aggregables is set to false, this will always be zero. Otherwise, it will return the field name as a symbol.



28
29
30
31
32
33
34
 
# File 'lib/mongoid/contextual/none.rb', line 28

def sum(_field = nil)
  if Mongoid.broken_aggregables
    old_sum(_field)
  else
    new_sum(_field)
  end
end

#take(limit = nil) ⇒ [] | nil

Returns nil or empty array.

Examples:

Take a document in null context.

context.take

Parameters:

  • limit (Integer | nil) (defaults to: nil) —

    The number of documents to take or nil.

Returns:

  • ([] | nil) —

    Empty array or nil.



164
165
166
 
# File 'lib/mongoid/contextual/none.rb', line 164

def take(limit = nil)
  limit ? [] : nil
end

#take! ⇒ Object

Always raises an error.

Examples:

Take a document in null context.

context.take!

Raises:



174
175
176
 
# File 'lib/mongoid/contextual/none.rb', line 174

def take!
  raise Errors::DocumentNotFound.new(klass, nil, nil)
end

#tally(_field) ⇒ Hash

Tally the field values in null context.

Examples:

Get the values for null context.

context.tally(:name)

Parameters:

  • _field (String | Symbol) —

    Field to tally.

Returns:

  • (Hash) —

    An empty Hash.



118
119
120
 
# File 'lib/mongoid/contextual/none.rb', line 118

def tally(_field)
  {}
end