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:



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# File 'lib/mongoid/contextual/none.rb', line 104

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

Instance Attribute Details

#criteria ⇒ Object (readonly)

Returns the value of attribute criteria.



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

def criteria
  @criteria
end

#klass ⇒ Object (readonly)

Returns the value of attribute klass.



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# 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.



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# 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.



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# 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.



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# 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.



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

def exists?; false; end

#last ⇒ nil

Always returns nil.

Examples:

Get the last document in null context.

context.last

Returns:

  • (nil) —

    Always nil.



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# File 'lib/mongoid/contextual/none.rb', line 114

def last; nil; end

#length ⇒ Integer Also known as: size

Always returns zero.

Examples:

Get the length of null context.

context.length

Returns:

  • (Integer) —

    Always zero.



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# File 'lib/mongoid/contextual/none.rb', line 122

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

#new_sum ⇒ Object 



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

alias :new_sum :sum

#old_sum ⇒ Object 



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

alias :old_sum :sum

#pluck(*args) ⇒ Array

Pluck the field values in null context.

Examples:

Get the values for null context.

context.pluck(:name)

Parameters:

  • args (String, Symbol, Array) —

    Field or fields to pluck.

Returns:

  • (Array) —

    An empty Array.



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

def pluck(*args)
  []
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.



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# 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