Class: Facetious::Facet

Inherits:
Struct
  • Object
show all
Defined in:
lib/facetious.rb

Constant Summary collapse

ValueConverter = 
{
  string:
    proc {|value| "'" + value.gsub(/'/, "''") + "'" },
  integer:
    proc {|value| Integer(value).to_s },
  date:
    proc {|value|
      raise "REVISIT: Don't use DATE VALUE before implementing it"
      value
    },
  integers:
    proc {|value|
      '(' + (value-['']).map{|i| Integer(i).to_s}.join(',') + ')'
    },
  strings:
    proc {|value|
      '(' + (value-['']).map{|str| sql_value(:string, str)}.join(',') + ')'
    }
}

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#data_type ⇒ Object

Returns the value of attribute data_type

Returns:

  • (Object) —

    the current value of data_type



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# File 'lib/facetious.rb', line 5

def data_type
  @data_type
end

#field_name ⇒ Object

Returns the value of attribute field_name

Returns:

  • (Object) —

    the current value of field_name



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# File 'lib/facetious.rb', line 5

def field_name
  @field_name
end

#name ⇒ Object

Returns the value of attribute name

Returns:

  • (Object) —

    the current value of name



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# File 'lib/facetious.rb', line 5

def name
  @name
end

#title ⇒ Object

Returns the value of attribute title

Returns:

  • (Object) —

    the current value of title



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# File 'lib/facetious.rb', line 5

def title
  @title
end

#where ⇒ Object

Returns the value of attribute where

Returns:

  • (Object) —

    the current value of where



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# File 'lib/facetious.rb', line 5

def where
  @where
end

Instance Method Details

#condition_for(value) ⇒ Object 



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# File 'lib/facetious.rb', line 32

def condition_for value
  name = field_name.to_s
  # puts "condition_for facet #{name}, value #{value.inspect}"
  conditions =
	case value
	when /\A\s*-\s*\Z/
	  if where =~ /\s*\(?\s*EXISTS\b/i
 nil # No condition will be used, rather the EXISTS will be negated.
	  else
 '('+name+' IS NULL OR '+name+" = '')"
	  end
	when /\A\s*\*\s*\Z/
	  "#{name} != ''"   # Which also means IS NOT NULL, incidentally
	when /,/
	  '('+
	  value.split(/,/).map(&:strip).map do |alternate|
 condition_for alternate
	  end.join(' OR ') +
	  ')'
	when /\A(>=?)(.*)/  # Greater than
	  name + " #{$1} " + sql_value(data_type, $2)
	when /\A(<=?)(.*)/  # Less than
	  name + " #{$1} " + sql_value(data_type, $2)
	when /\A~(.*)/    # Near this value
	  # name + ...
	when /\A(.*)\.\.(.*)\z/ # Between
	  name + " >= " + sql_value(data_type, $1) + " AND " +
	  name + " <= " + sql_value(data_type, $2)
	when /%/
	  name + " LIKE " + sql_value(data_type, value)
	when Array
	  '(' + value.map{|v| condition_for v }*' OR ' + ')'
	when Range
	  name + " >= " + sql_value(data_type, value.begin.to_s) + " AND " +
	  name + " <= " + sql_value(data_type, value.end.to_s)
	else      # Equals
	  if [:integers, :strings].include?(data_type)
 name + " IN " + sql_value(data_type, value.to_s)
	  else
 name + " = " + sql_value(data_type, value.to_s)
	  end
	end

  if sql = where
	if sql.include?('?')
	  if conditions
 sql.gsub(/\?/, "  AND "+conditions)
	  else  # Make an EXISTS clause into NOT EXISTS (see above)
 'NOT '+sql.gsub(/\?/, '')
	  end
	else
	  if sql.match /{{.*}}/
 name + sql.gsub(/{{.*}}/, sql_value(data_type, value))
	  else
 sql + "WHERE\t"+conditions
	  end
	end
  else
	conditions
  end
end

#sql_value(data_type, value) ⇒ Object 



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# File 'lib/facetious.rb', line 26

def sql_value data_type, value
  conversion_proc = ValueConverter[data_type]
  raise "facet data type #{data_type} is not recognised" unless conversion_proc
  conversion_proc.call(value)
end