Class: MetaWhere::Visitors::Visitor

Inherits:
Object
  • Object
show all
Includes:
Utility
Defined in:
lib/meta_where/visitors/visitor.rb

Direct Known Subclasses

Attribute, Predicate

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(join_dependency) ⇒ Visitor

Returns a new instance of Visitor.



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# File 'lib/meta_where/visitors/visitor.rb', line 10

def initialize(join_dependency)
  @join_dependency = join_dependency
  jb = join_dependency.join_base
  @engine = jb.arel_engine
  @default_table = Arel::Table.new(jb.table_name, :as => jb.aliased_table_name, :engine => @engine)
  @tables = Hash.new {|hash, key| hash[key] = get_table(key)}
end

Instance Attribute Details

#join_dependency ⇒ Object (readonly)

Returns the value of attribute join_dependency.



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# File 'lib/meta_where/visitors/visitor.rb', line 8

def join_dependency
  @join_dependency
end

#tables ⇒ Object (readonly)

Returns the value of attribute tables.



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# File 'lib/meta_where/visitors/visitor.rb', line 8

def tables
  @tables
end

Instance Method Details

#accept(object, parent = nil) ⇒ Object 



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# File 'lib/meta_where/visitors/visitor.rb', line 28

def accept(object, parent = nil)
  visit(object, parent)
end

#can_accept?(object) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/meta_where/visitors/visitor.rb', line 32

def can_accept?(object)
  respond_to? DISPATCH[object.class]
end

#get_table(parent_or_table_name = nil) ⇒ Object 



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# File 'lib/meta_where/visitors/visitor.rb', line 18

def get_table(parent_or_table_name = nil)
  if parent_or_table_name.is_a?(Symbol)
    Arel::Table.new(parent_or_table_name, :engine => @engine)
  elsif parent_or_table_name.respond_to?(:aliased_table_name)
    Arel::Table.new(parent_or_table_name.table_name, :as => parent_or_table_name.aliased_table_name, :engine => @engine)
  else
    @default_table
  end
end