Module: Surrealist::StringUtils

Defined in:
lib/surrealist/string_utils.rb

Overview

A helper class for strings transformations.

Constant Summary collapse

DASH = 
'-'
UNDERSCORE = 
'_'
EMPTY_STRING = 
''
DASH_REGEXP1 = 
/([A-Z]+)([A-Z][a-z])/o.freeze
DASH_REGEXP2 = 
/([a-z\d])([A-Z])/o.freeze
UNDERSCORE_REGEXP = 
/(?:^|_)([^_\s]+)/o.freeze
NAMESPACES_SEPARATOR = 
'::'
UNDERSCORE_SUBSTITUTE = 
'\1_\2'

Class Method Summary collapse

Class Method Details

.break_namespaces(klass, camelize, nesting_level) ⇒ Hash

Extracts n amount of classes from a namespaces and returns a nested hash.

Examples:

3 levels

klass = 'Business::System::Cashier::Reports::Withdraws'
break_namespaces(klass, camelize: false, nesting_level: 3)
# => { cashier: { reports: { withdraws: {} } } }

Parameters:

  • klass (String) —

    full namespace as a string.

  • camelize (Boolean) —

    optional camelize argument.

  • nesting_level (Integer) —

    level of required nesting.

Returns:

  • (Hash) —

    a nested hash.

Raises:

  • Surrealist::InvalidNestingLevel if nesting level is specified as 0.



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# File 'lib/surrealist/string_utils.rb', line 72

def break_namespaces(klass, camelize, nesting_level)
  Surrealist::ExceptionRaiser.raise_invalid_nesting!(nesting_level) unless nesting_level.positive?

  klass.split(NAMESPACES_SEPARATOR).last(nesting_level).reverse!.inject({}) do |a, n|
    key = (camelize ? camelize(uncapitalize(n), false) : underscore(n)).to_sym

    { key => a }
  end
end

.camelize(snake_string, first_upper = true) ⇒ String

Camelizes a string.

Parameters:

  • snake_string (String) —

    a string to be camelized.

  • first_upper (Boolean) (defaults to: true) —

    should the first letter be capitalized.

Returns:

  • (String) —

    camelized string.



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# File 'lib/surrealist/string_utils.rb', line 36

def camelize(snake_string, first_upper = true)
  if first_upper
    snake_string.to_s.gsub(UNDERSCORE_REGEXP) { Regexp.last_match[1].capitalize }
  else
    parts = snake_string.split(UNDERSCORE, 2)
    parts[0].concat(camelize(parts[1])) if parts.size > 1
    parts[0] || EMPTY_STRING
  end
end

.extract_class(string) ⇒ String

Extracts bottom-level class from a namespace.

Examples:

Extract class

extract_class('Animal::Dog::Collie') # => 'Collie'

Parameters:

  • string (String) —

    full namespace

Returns:

  • (String) —

    extracted class



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# File 'lib/surrealist/string_utils.rb', line 54

def extract_class(string)
  uncapitalize(string.split(NAMESPACES_SEPARATOR).last)
end

.underscore(string) ⇒ String

Converts a string to snake_case.

Parameters:

  • string (String) —

    a string to be underscored.

Returns:

  • (String) —

    new underscored string.



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# File 'lib/surrealist/string_utils.rb', line 21

def underscore(string)
  dup = string.gsub(NAMESPACES_SEPARATOR, UNDERSCORE)
  dup.gsub!(DASH_REGEXP1, UNDERSCORE_SUBSTITUTE)
  dup.gsub!(DASH_REGEXP2, UNDERSCORE_SUBSTITUTE)
  dup.tr!(DASH, UNDERSCORE)
  dup.downcase!
  dup
end