Class: Cuprum::Collections::Scopes::Criteria::Parser

Inherits:
Object
  • Object
show all
Defined in:
lib/cuprum/collections/scopes/criteria/parser.rb

Overview

Helper for generating criteria from hash or block inputs.

Defined Under Namespace

Classes: BlockParser

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.instance ⇒ Cuprum::Collections::Scopes::Criteria::Parser

Returns a singleton instance of the parser class.

Returns:



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# File 'lib/cuprum/collections/scopes/criteria/parser.rb', line 112

def instance
  @instance ||= new
end

.validate_hash(value) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/cuprum/collections/scopes/criteria/parser.rb', line 117

def validate_hash(value)
  return if valid_hash?(value)

  message = 'value must be a Hash with String or Symbol keys'

  raise ArgumentError, message, caller(1..-1)
end

Instance Method Details

#parse(value = nil) { ... } ⇒ Array

Converts a valid query hash and/or block to criteria.

The block must return a Hash with String keys. The hash values must either be literal values (e.g. a String, an Integer, etc) or a call to an operator function.

Parameters:

  • value (Hash, nil) (defaults to: nil) —

    the keys and values to parse.

Yields:

  • the query block.

Yield Returns:

  • (Hash) —

    a Hash with String keys.

Returns:

  • (Array) —

    the generated criteria.



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# File 'lib/cuprum/collections/scopes/criteria/parser.rb', line 150

def parse(value = UNKNOWN, &)
  if block_given? && value != UNKNOWN
    parse_hash(value) + parse_block(&)
  elsif value.is_a?(Proc)
    parse_block(&value)
  elsif value == UNKNOWN
    parse_block(&)
  else
    parse_hash(value)
  end
end

#parse_block { ... } ⇒ Array

Converts a valid query block to criteria.

The block must return a Hash with String keys. The hash values must either be literal values (e.g. a String, an Integer, etc) or a call to an operator function.

Yields:

  • the query block.

Yield Returns:

  • (Hash) —

    a Hash with String keys.

Returns:

  • (Array) —

    the generated criteria.



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# File 'lib/cuprum/collections/scopes/criteria/parser.rb', line 173

def parse_block(...) # rubocop:disable Metrics/MethodLength
  raise ArgumentError, 'no block given' unless block_given?

  value = evaluate_block(...)

  Parser.validate_hash(value)

  value.map do |attribute, filter|
    if filter.is_a?(OperatorExpression)
      [attribute.to_s, filter.operator, filter.value]
    else
      operator = Cuprum::Collections::Queries::Operators::EQUAL

      [attribute.to_s, operator, filter]
    end
  end
rescue NameError => exception
  raise Cuprum::Collections::Queries::UnknownOperatorException,
    %(unknown operator "#{exception.name}")
end

#parse_hash(value) ⇒ Array

Converts a hash of expected keys and values to criteria.

Parameters:

  • value (Hash) —

    the keys and values to parse.

Returns:

  • (Array) —

    the generated criteria.



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# File 'lib/cuprum/collections/scopes/criteria/parser.rb', line 199

def parse_hash(value)
  Parser.validate_hash(value)

  operator = Cuprum::Collections::Queries::Operators::EQUAL

  value.map do |attribute, filter|
    [attribute.to_s, operator, filter]
  end
end