Class: ComparisonPredicate

Inherits:
Object
  • Object
show all
Defined in:
lib/predicates/comparison_predicate.rb

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(operator, lhs, rhs, options = [], modifier = "") ⇒ ComparisonPredicate

Returns a new instance of ComparisonPredicate.



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# File 'lib/predicates/comparison_predicate.rb', line 7

def initialize(operator, lhs, rhs, options = [], modifier = "")
  @operator = operator
  @lhs = PredicateLiteral.parse(lhs)
  @rhs = PredicateLiteral.parse(rhs)
  @options = options
  @modifer = modifier
end

Class Method Details

.parse(array) ⇒ Object 



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# File 'lib/predicates/comparison_predicate.rb', line 3

def self.parse(array)
  self.new(array[1], array[2], array[3], array[4], array[5])
end

Instance Method Details

#build_arel(arel_table) ⇒ Object 



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# File 'lib/predicates/comparison_predicate.rb', line 15

def build_arel(arel_table)
  lhs = @lhs.build_arel(arel_table)
  rhs = @rhs.build_arel(arel_table)
  case @operator
    when "=="
      # The left-hand expression is equal to the right-hand expression.
      return lhs.eq(rhs)

    when ">="
      # The left-hand expression is greater than or equal to the right-hand expression.
      return lhs.gteq(rhs)

    when "<="
      # The left-hand expression is less than or equal to the right-hand expression.
      return lhs.lteq(rhs)

    when ">"
      # The left-hand expression is greater than the right-hand expression.
      return lhs.gt(rhs)

    when "<"
      # The left-hand expression is less than the right-hand expression.
      return lhs.lt(rhs)

    when "!="
      # The left-hand expression is not equal to the right-hand expression.
      return lhs.not_eq(rhs)

    when "BEGINSWITH"
      # The left-hand expression begins with the right-hand expression.
      return lhs.matches("%#{rhs}")

    when "CONTAINS"
      # The left-hand expression contains the right-hand expression.
      return lhs.matches("%#{rhs}%")

    when "ENDSWITH"
      # The left-hand expression ends with the right-hand expression.
      return lhs.matches("#{rhs}%")

    when "LIKE"
      # The left hand expression equals the right-hand expression: ? and * are allowed as wildcard characters,
      # where ? matches 1 character and * matches 0 or more characters.
      return lhs.matches(rhs.tr("*?", "%_"))

    when "MATCHES"
      # The left hand expression equals the right hand expression using a regex-style comparison according to
      # ICU v3 (for more details see the ICU User Guide for Regular Expressions).
      raise "MATCHES Operator (RegExps) not supported!"

    when "IN"
      return lhs.in(rhs)

    else
      raise "Unknown Operator #{@operator}"
  end
end