Class: MassiveRecord::ORM::Finders::Scope

Inherits:
Object
  • Object
show all
Defined in:
lib/massive_record/orm/finders/scope.rb

Overview

A finder scope’s jobs is to contain and build up limitations and meta data of a DB query about to being executed, allowing us to call for instance

User.select(:info).limit(5) or User.select(:info).find(a_user_id)

Each call adds restrictions or info about the query about to be executed, and the proxy will act as an Enumerable object when asking for multiple values

Constant Summary collapse

MULTI_VALUE_METHODS = 
%w(select)
SINGLE_VALUE_METHODS = 
%w(limit starts_with offset)

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(klass) ⇒ Scope

Returns a new instance of Scope.



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# File 'lib/massive_record/orm/finders/scope.rb', line 30

def initialize(klass)
  @klass = klass
  @extra_finder_options = {}

  reset
  reset_single_values_options
  reset_multi_values_options
end

Instance Attribute Details

#extra_finder_options ⇒ Object

Returns the value of attribute extra_finder_options.



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# File 'lib/massive_record/orm/finders/scope.rb', line 23

def extra_finder_options
  @extra_finder_options
end

#klass ⇒ Object

Returns the value of attribute klass.



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# File 'lib/massive_record/orm/finders/scope.rb', line 23

def klass
  @klass
end

#loaded ⇒ Object Also known as: loaded?

Returns the value of attribute loaded.



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# File 'lib/massive_record/orm/finders/scope.rb', line 23

def loaded
  @loaded
end

Instance Method Details

#==(other) ⇒ Object 



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# File 'lib/massive_record/orm/finders/scope.rb', line 80

def ==(other)
  case other
  when Scope
    object_id == other.object_id
  when Array
    to_a == other
  else
    raise "Don't know how to compare #{self.class} with #{other.class}"
  end
end

#all(options = {}) ⇒ Object 



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# File 'lib/massive_record/orm/finders/scope.rb', line 103

def all(options = {})
  if options.empty?
    to_a
  else
    apply_finder_options(options).to_a
  end
end

#apply_finder_options(options) ⇒ Object

Takes a hash of finder options, applies them to a new scope and returns a that scope.



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# File 'lib/massive_record/orm/finders/scope.rb', line 137

def apply_finder_options(options)
  scope = clone
  return scope if options.empty?

  options.each do |scope_method, arguments|
    if respond_to? scope_method
      scope = scope.send(scope_method, arguments)
    else
      scope.extra_finder_options[scope_method] = arguments              
    end
  end

  scope
end

#find(*args) ⇒ Object 



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# File 'lib/massive_record/orm/finders/scope.rb', line 93

def find(*args)
  options = args.extract_options!.to_options
  
  if options.any?
    apply_finder_options(options).find(*args)
  else
    klass.do_find(*args << find_options)
  end
end

#first(options = {}) ⇒ Object 



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# File 'lib/massive_record/orm/finders/scope.rb', line 111

def first(options = {})
  if loaded? && options.empty?
    @records.first
  else
    apply_finder_options(options).limit(1).to_a.first
  end
end

#initialize_copy(old) ⇒ Object 



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# File 'lib/massive_record/orm/finders/scope.rb', line 39

def initialize_copy(old)
  reset
end

#last(*args) ⇒ Object 



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# File 'lib/massive_record/orm/finders/scope.rb', line 119

def last(*args)
  raise "Sorry, but query last requires all records to be fetched. If you really want to do this, do an scope.all.last instead."
end

#limit(limit) ⇒ Object

Single value options



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# File 'lib/massive_record/orm/finders/scope.rb', line 64

def limit(limit)
  cloned_version_with { self.limit_value = limit }
end

#offset(offset) ⇒ Object 



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# File 'lib/massive_record/orm/finders/scope.rb', line 72

def offset(offset)
  cloned_version_with { self.offset_value = offset }
end

#reset ⇒ Object 



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# File 'lib/massive_record/orm/finders/scope.rb', line 44

def reset
  @loaded = false
  @records = []
end

#select(*select) ⇒ Object

Multi value options



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# File 'lib/massive_record/orm/finders/scope.rb', line 55

def select(*select)
  cloned_version_with { self.select_values |= select.flatten.compact.collect(&:to_s) }
end

#starts_with(starts_with) ⇒ Object 



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# File 'lib/massive_record/orm/finders/scope.rb', line 68

def starts_with(starts_with)
  cloned_version_with { self.starts_with_value = starts_with }
end

#to_a ⇒ Object 



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# File 'lib/massive_record/orm/finders/scope.rb', line 125

def to_a
  return @records if loaded?
  @records = load_records
  @records = [@records] unless @records.is_a? Array
  @records
end