Class: HashToConditions::ArrayHelper

Inherits:
Object
  • Object
show all
Defined in:
lib/helpers/array_helper.rb

Overview

This helper class takes a Hash key-value pair (an Array) and return the expanded form condition.

For example:

> helper = ArrayHelper.new(['age.gt', 18])
> helper.to_condition => ['age>?', 18]

Instance Method Summary collapse

Instance Method Details

#to_condition ⇒ Object

Returns an expanded form condition or a Hash if it is a nested condition.

An exception is raised when specific validation fails. Possible exception messages are:

  • ‘bad_key_value_pair’ - array must have exactly two (2) elements

  • ‘field_cannot_be_empty’ - a field name must be specified

  • ‘unknown_operator’ - operator tag is not supported



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# File 'lib/helpers/array_helper.rb', line 18

def to_condition
  raise "bad_key_value_pair" unless @array.length == 2

  parts = @array.first.to_s.split('.')
  raise "field_cannot_be_empty" if parts.empty?

  field = parts[0].strip.to_s
  operator = parts[1]
  value = @array.last

  if ['AND', 'OR'].index(field.upcase)
    # handle nested condition
    return {field.upcase => value}
  end

  unless operator
    # handle implicit .eq ({'name' => 'value'}) or .like ({'name' => 'value%'})
    operator = value.to_s.index('%') ? 'like' : 'eq'
  end
  operator = operator.to_s.downcase
  mapped = operator.to_operator
  raise "unknown_operator" unless mapped

  # handle .null or .nnull, suppress value
  return  [field + mapped] if operator.index('null')

  return [field + mapped, value] unless ['in', 'between'].index(operator)

  handle_in_between(operator, field, mapped, value)
end