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Module: Mongoid::Criteria::Queryable::Aggregable

Relationships & Source Files
Extension / Inclusion / Inheritance Descendants
Included In:
::Mongoid::Criteria, ::Mongoid::Criteria::Queryable
Super Chains via Extension / Inclusion / Inheritance
Class Chain:
self, Macroable
Defined in: lib/mongoid/criteria/queryable/aggregable.rb

Overview

Provides a DSL around crafting aggregation framework commands.

Class Method Summary

Macroable - Extended

key

Adds a method on ::Symbol for convenience in where queries for the provided operators.

Instance Attribute Summary

Instance Method Summary

Instance Attribute Details

#aggregating Flag for whether or not we are aggregating.(Flag for whether or not we are aggregating.) (rw)

[ GitHub ] 

  


# File 'lib/mongoid/criteria/queryable/aggregable.rb', line 16



attr_writer :aggregating


  








  

    #aggregating=(value)   (rw)
  

  [ GitHub ]


  

  


# File 'lib/mongoid/criteria/queryable/aggregable.rb', line 16



attr_writer :aggregating


  








  

    #aggregating?  ⇒ true | false  (rw)
  



  

    

Has the aggregable enter an aggregation state. Ie, are only aggregation operations allowed at this point on.


  





    

    
Examples:

        


Is the aggregable aggregating?



      
aggregable.aggregating?

  


Returns:


    
  
  • 
    (true | false)
—    
    

    If the aggregable is aggregating.
    

    
  
    • 





  [ GitHub ]


  

  


# File 'lib/mongoid/criteria/queryable/aggregable.rb', line 25



def aggregating?
  !!@aggregating
end


  








  

    #pipeline   (readonly)
  

  [ GitHub ]


  

  


# File 'lib/mongoid/criteria/queryable/aggregable.rb', line 13



attr_reader :pipeline


  








  

    #pipeline The aggregation pipeline.(The aggregation pipeline.)   (readonly)
  

  [ GitHub ]


  

  


# File 'lib/mongoid/criteria/queryable/aggregable.rb', line 13



attr_reader :pipeline


  







Instance Method Details



  

    #aggregation(operation)  ⇒ Aggregable  (private)
  

  

    This method is for internal use only.
  



  

    

Add the aggregation operation.


  





    

    
Examples:

        


Aggregate on the operation.



      
aggregation(operation) do |pipeline|
  pipeline.push("$project" => operation)
end

  


Parameters:


    
  
  • 
    operation
    (Hash)
—    
    

    The operation for the pipeline.
    

    
  
    • 



Returns:


    
  
  • 
    (Aggregable)
—    
    

    The cloned aggregable.
    

    
  
    • 





  [ GitHub ]


  

  


# File 'lib/mongoid/criteria/queryable/aggregable.rb', line 96



def aggregation(operation)
  return self unless operation
  clone.tap do |query|
    unless aggregating?
      query.pipeline.concat(query.selector.to_pipeline)
      query.pipeline.concat(query.options.to_pipeline)
      query.aggregating = true
    end
    yield(query.pipeline)
  end
end


  








  

    #group(operation)  ⇒ Aggregable 
  



  

    

Add a group ($group) operation to the aggregation pipeline.


  





    

    
Examples:

        


Add a group operation being verbose.



      
aggregable.group(count: { "$sum" => 1 }, max: { "$max" => "likes" })

        


Add a group operation using symbol shortcuts.



      
aggregable.group(:count.sum => 1, :max.max => "likes")

  


Parameters:


    
  
  • 
    operation
    (Hash)
—    
    

    The group operation.
    

    
  
    • 



Returns:


    
  
  • 
    (Aggregable)
—    
    

    The aggregable.
    

    
  
    • 





  [ GitHub ]


  

  


# File 'lib/mongoid/criteria/queryable/aggregable.rb', line 40



def group(operation)
  aggregation(operation) do |pipeline|
    pipeline.group(operation)
  end
end


  








  

    #project(operation = nil)  ⇒ Aggregable 
  



  

    

Add a projection ($project) to the aggregation pipeline.


  





    

    
Examples:

        


Add a projection to the pipeline.



      
aggregable.project(author: 1, name: 0)

  


Parameters:


    
  
  • 
    operation
    (Hash)
    (defaults to: nil)
—    
    

    The projection to make.
    

    
  
    • 



Returns:


    
  
  • 
    (Aggregable)
—    
    

    The aggregable.
    

    
  
    • 





  [ GitHub ]


  

  


# File 'lib/mongoid/criteria/queryable/aggregable.rb', line 62



def project(operation = nil)
  aggregation(operation) do |pipeline|
    pipeline.project(operation)
  end
end


  








  

    #unwind(field)  ⇒ Aggregable 
  



  

    

Add an unwind ($unwind) to the aggregation pipeline.


  





    

    
Examples:

        


Add an unwind to the pipeline.



      
aggregable.unwind(:field)

  


Parameters:


    
  
  • 
    field
    (String | Symbol)
—    
    

    The name of the field to unwind.
    

    
  
    • 



Returns:


    
  
  • 
    (Aggregable)
—    
    

    The aggregable.
    

    
  
    • 





  [ GitHub ]


  

  


# File 'lib/mongoid/criteria/queryable/aggregable.rb', line 76



def unwind(field)
  aggregation(field) do |pipeline|
    pipeline.unwind(field)
  end
end