Class: Dynamoid::Criteria::Chain

Inherits:
Object
  • Object
show all
Includes:
Enumerable
Defined in:
lib/dynamoid/criteria/chain.rb

Overview

The criteria chain is equivalent to an ActiveRecord relation (and realistically I should change the name from chain to relation). It is a chainable object that builds up a query and eventually executes it either on an index or by a full table scan.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(source) ⇒ Chain

Create a new criteria chain.

Parameters:

  • source (Class) —

    the class upon which the ultimate query will be performed.



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# File 'lib/dynamoid/criteria/chain.rb', line 15

def initialize(source)
  @query = {}
  @source = source
  @consistent_read = false
end

Instance Attribute Details

#consistent_read ⇒ Object

Returns the value of attribute consistent_read.



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# File 'lib/dynamoid/criteria/chain.rb', line 9

def consistent_read
  @consistent_read
end

#index=(value) ⇒ Object

Sets the attribute index

Parameters:

  • value —

    the value to set the attribute index to.



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# File 'lib/dynamoid/criteria/chain.rb', line 9

def index=(value)
  @index = value
end

#limit(limit) ⇒ Object

Returns the value of attribute limit.



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# File 'lib/dynamoid/criteria/chain.rb', line 9

def limit
  @limit
end

#query ⇒ Object

Returns the value of attribute query.



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# File 'lib/dynamoid/criteria/chain.rb', line 9

def query
  @query
end

#source ⇒ Object

Returns the value of attribute source.



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# File 'lib/dynamoid/criteria/chain.rb', line 9

def source
  @source
end

#start(start) ⇒ Object

Returns the value of attribute start.



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# File 'lib/dynamoid/criteria/chain.rb', line 9

def start
  @start
end

#values ⇒ Object

Returns the value of attribute values.



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# File 'lib/dynamoid/criteria/chain.rb', line 9

def values
  @values
end

Instance Method Details

#all ⇒ Object

Returns all the records matching the criteria.

Since:

  • 0.2.0



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# File 'lib/dynamoid/criteria/chain.rb', line 45

def all
  records
end

#consistent ⇒ Object 



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# File 'lib/dynamoid/criteria/chain.rb', line 37

def consistent
  @consistent_read = true
  self
end

#consistent_opts ⇒ Object 



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# File 'lib/dynamoid/criteria/chain.rb', line 73

def consistent_opts
  { :consistent_read => consistent_read }
end

#each(&block) ⇒ Object

Allows you to use the results of a search as an enumerable over the results found.

Since:

  • 0.2.0



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# File 'lib/dynamoid/criteria/chain.rb', line 69

def each(&block)
  records.each(&block)
end

#first ⇒ Object

Returns the first record matching the criteria.

Since:

  • 0.2.0



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# File 'lib/dynamoid/criteria/chain.rb', line 52

def first
  limit(1).first
end

#where(args) ⇒ Object

The workhorse method of the criteria chain. Each key in the passed in hash will become another criteria that the ultimate query must match. A key can either be a symbol or a string, and should be an attribute name or an attribute name with a range operator.

Examples:

A simple criteria

where(:name => 'Josh')

A more complicated criteria

where(:name => 'Josh', 'created_at.gt' => DateTime.now - 1.day)

Since:

  • 0.2.0



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# File 'lib/dynamoid/criteria/chain.rb', line 32

def where(args)
  args.each {|k, v| query[k] = v}
  self
end