Module: ArelExtensions::Math

Included in:
Attributes
Defined in:
lib/arel_extensions/math.rb

Instance Method Summary collapse

Instance Method Details

#+(other) ⇒ Object

function + between String and others (convert in string) allows you to concatenate 2 or more strings together. Date and integer adds or subtracts a specified time interval from a date.



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# File 'lib/arel_extensions/math.rb', line 17

def +(other)
	  case self
	  when Arel::Nodes::Quoted
		return self.concat(other)  
	  when Arel::Nodes::Grouping
		if self.expr.left.is_a?(String) || self.expr.right.is_a?(String) 
return self.concat(other)
		else		
return Arel::Nodes::Grouping.new(Arel::Nodes::Addition.new self, other)
		end
	  when  ArelExtensions::Nodes::Function,ArelExtensions::Nodes::Case
return case self.return_type
when :string, :text			
			self.concat(other)
when :integer, :decimal, :float, :number, :int
			Arel::Nodes::Grouping.new(Arel::Nodes::Addition.new self, other)
when :date, :datetime
			ArelExtensions::Nodes::DateAdd.new [self, other]
else
			self.concat(other)
end 
	  when  Arel::Nodes::Function
		Arel::Nodes::Grouping.new(Arel::Nodes::Addition.new self, other)
	  else		  
begin 
			col = Arel::Table.engine.connection.schema_cache.columns_hash(self.relation.table_name)[self.name.to_s]
rescue Exception
			col = nil
end
if (!col) #if the column doesn't exist in the database
			Arel::Nodes::Grouping.new(Arel::Nodes::Addition.new(self, other))
else
			arg = col.type
			if arg == :integer || (!arg)
 other = other.to_i if other.is_a?(String)
 Arel::Nodes::Grouping.new(Arel::Nodes::Addition.new self, other)
			elsif arg == :decimal || arg == :float
 other = Arel.sql(other) if other.is_a?(String) # Arel should accept Float & BigDecimal!
 Arel::Nodes::Grouping.new(Arel::Nodes::Addition.new self, other)
			elsif arg == :datetime || arg == :date
 ArelExtensions::Nodes::DateAdd.new [self, other]
			elsif arg == :string || arg == :text
 self.concat(other)
			end  
end
	  end
end

#-(other) ⇒ Object

function returns the time between two dates function returns the substraction between two ints



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# File 'lib/arel_extensions/math.rb', line 67

def -(other)
	  case self
	  when Arel::Nodes::Grouping
		if self.expr.left.is_a?(Date) || self.expr.left.is_a?(DateTime) 
Arel::Nodes::Grouping.new(ArelExtensions::Nodes::DateSub.new [self, other])
		else		
Arel::Nodes::Grouping.new(Arel::Nodes::Subtraction.new(self, other))
		end
	  when ArelExtensions::Nodes::Function, ArelExtensions::Nodes::Case
case self.return_type
when :string, :text # ???
			Arel::Nodes::Grouping.new(Arel::Nodes::Subtraction.new(self, other)) # ??
when :integer, :decimal, :float, :number
			Arel::Nodes::Grouping.new(Arel::Nodes::Subtraction.new(self, other))
when :date, :datetime
			ArelExtensions::Nodes::DateSub.new [self, other]
else
			Arel::Nodes::Grouping.new(Arel::Nodes::Subtraction.new(self, other))
end 
	  when Arel::Nodes::Function
		Arel::Nodes::Grouping.new(Arel::Nodes::Subtraction.new(self, other))
	  else
		
		begin 
			col = Arel::Table.engine.connection.schema_cache.columns_hash(self.relation.table_name)[self.name.to_s]
		rescue Exception
			col = nil
		end
		if (!col) #if the column doesn't exist in the database
			Arel::Nodes::Grouping.new(Arel::Nodes::Subtraction.new(self, other))
		else
			arg = col.type
			if (arg == :date || arg == :datetime)
case other
when Arel::Attributes::Attribute
  begin 
    col2 = Arel::Table.engine.connection.schema_cache.columns_hash(other.relation.table_name)[other.name.to_s]
  rescue Exception
	col = nil
  end
  if (!col2) #if the column doesn't exist in the database
	ArelExtensions::Nodes::DateSub.new [self, other]
  else
	arg2 = col2.type
	if arg2 == :date || arg2 == :datetime
	  ArelExtensions::Nodes::DateDiff.new [self, other]
	else
	  ArelExtensions::Nodes::DateSub.new [self, other]
	end
  end  
when Arel::Nodes::Node, DateTime, Time, String, Date
  ArelExtensions::Nodes::DateDiff.new [self, other]
when Integer
  ArelExtensions::Nodes::DateSub.new [self, other]
end
			else
case other
when Integer, Float, BigDecimal
  Arel::Nodes::Grouping.new(Arel::Nodes::Subtraction.new(self, Arel.sql(other.to_s)))
when String
  Arel::Nodes::Grouping.new(Arel::Nodes::Subtraction.new(self, Arel.sql(other)))
else
  Arel::Nodes::Grouping.new(Arel::Nodes::Subtraction.new(self, other))
end
			end
		end
	  end
end