Class: Enumpath::Operator::FilterExpression

Inherits:
Base
  • Object
show all
Defined in:
lib/enumpath/operator/filter_expression.rb

Overview

Implements JSONPath filter expression operator syntax. See README for syntax and examples

Constant Summary collapse

COMPARISON_OPERATOR_REGEX = 
/(==|!=|>=|<=|<=>|>|<|=~|!~)/
LOGICAL_OPERATORS_REGEX = 
/(&&)|(\|\|)/
OPERATOR_REGEX = 
/^\?\((.*)\)$/

Instance Attribute Summary

Attributes inherited from Base

#operator

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Base

#initialize

Constructor Details

This class inherits a constructor from Enumpath::Operator::Base

Class Method Details

.detect?(operator) ⇒ true, false

Whether the operator matches OPERATOR_REGEX

Parameters:

  • operator (String) —

    the the full, normalized operator to test

Returns:

  • (true, false) —

    whether the operator param appears to represent the operator class



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# File 'lib/enumpath/operator/filter_expression.rb', line 19

def detect?(operator)
  !!(operator =~ OPERATOR_REGEX)
end

Instance Method Details

#apply(remaining_path, enum, resolved_path) {|remaining_path, enum, resolved_path| ... } ⇒ Object

Yields to the block once for each member of the enumerable that passes the filter expression

Parameters:

  • remaining_path (Array) —

    an array containing the normalized path segments yet to be resolved

  • enum (Enumerable) —

    the object to apply the operator to

  • resolved_path (Array) —

    an array containing the static path segments that have been resolved

Yields:

  • A block that will be called if the operator is applied successfully. If the operator cannot or should not be applied then the block is not yielded.

Yield Parameters:

  • remaining_path (Array) —

    remaining_path

  • enum (Enumerable) —

    the member of the enumerable that passed the filter

  • resolved_path (Array) —

    resolved_path plus the key for each member of the enumerable that passed the filter



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# File 'lib/enumpath/operator/filter_expression.rb', line 32

def apply(remaining_path, enum, resolved_path, &block)
  Enumpath.log('Evaluating filter expression') { { expression: operator, to: enum } }

  _match, unpacked_operator = OPERATOR_REGEX.match(operator).to_a
  expressions = unpacked_operator.split(LOGICAL_OPERATORS_REGEX).map(&:strip)

  keys(enum).each do |key|
    value = Enumpath::Resolver::Simple.resolve(key, enum)
    Enumpath.log('Applying filter to key') { { key: key, enum: value } }
    if pass?(expressions.dup, value)
      Enumpath.log('Applying filtered key') { { 'filtered key': key, 'filtered enum': value } }
      yield(remaining_path, value, resolved_path + [key.to_s])
    end
  end
end