Class: Kebab::Identifier

Inherits:
Object
  • Object
show all
Defined in:
lib/kebab/identifier.rb

Overview

This class provides some string-manipulation methods specific to slugs.

Note that this class includes many “bang methods” such as #clean! and #normalize! that perform actions on the string in-place. Each of these methods has a corresponding “bangless” method (i.e., Identifier#clean! and Identifier#clean) which does not appear in the documentation because it is generated dynamically.

All of the bang methods return an instance of String, while the bangless versions return an instance of Kebab::Identifier, so that calls to methods specific to this class can be chained:

string = Identifier.new("hello world")
string.with_separators! # => "hello-world"
string.with_separators  # => <Kebab::Identifier:0x000001013e1590 @wrapped_string="hello-world">

See Also:

Constant Summary collapse

Error = 
Class.new(StandardError)
@@utf8_proxy = 
if Kebab.jruby15?
  UTF8::JavaProxy
elsif defined? Unicode::VERSION
  UTF8::UnicodeProxy
elsif defined? ActiveSupport
  UTF8::ActiveSupportProxy
else
  UTF8::DumbProxy
end

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(string) ⇒ Identifier

Returns a new instance of Identifier.

Parameters:

  • string (#to_s) —

    The string to use as the basis of the Identifier.



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# File 'lib/kebab/identifier.rb', line 66

def initialize(string)
  @wrapped_string = string.to_s
  tidy_bytes!
  normalize_utf8!
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(symbol, *args, &block) ⇒ Object 



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# File 'lib/kebab/identifier.rb', line 61

def method_missing(symbol, *args, &block)
  @wrapped_string.__send__(symbol, *args, &block)
end

Instance Attribute Details

#wrapped_string ⇒ Object (readonly) Also known as: to_s

Returns the value of attribute wrapped_string.



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# File 'lib/kebab/identifier.rb', line 36

def wrapped_string
  @wrapped_string
end

Class Method Details

.utf8_proxy ⇒ Object

Return the proxy used for UTF-8 support.

See Also:



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# File 'lib/kebab/identifier.rb', line 51

def self.utf8_proxy
  @@utf8_proxy
end

.utf8_proxy=(obj) ⇒ Object

Set a proxy object used for UTF-8 support.

See Also:



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# File 'lib/kebab/identifier.rb', line 57

def self.utf8_proxy=(obj)
  @@utf8_proxy = obj
end

Instance Method Details

#==(value) ⇒ Object 



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# File 'lib/kebab/identifier.rb', line 72

def ==(value)
  @wrapped_string.to_s == value.to_s
end

#clean! ⇒ Object

Converts dashes to spaces, removes leading and trailing spaces, and replaces multiple whitespace characters with a single space.

Returns:

  • String



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# File 'lib/kebab/identifier.rb', line 132

def clean!
  @wrapped_string = @wrapped_string.gsub("-", " ").squeeze(" ").strip
end

#default_normalize_options ⇒ Object

The default options for #normalize!. Override to set your own defaults.



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# File 'lib/kebab/identifier.rb', line 274

def default_normalize_options
  {:transliterate => true, :max_length => 255, :separator => "-"}
end

#downcase! ⇒ Object

Perform UTF-8 sensitive downcasing.

Returns:

  • String



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# File 'lib/kebab/identifier.rb', line 242

def downcase!
  @wrapped_string = @@utf8_proxy.downcase(@wrapped_string)
end

#empty? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/kebab/identifier.rb', line 80

def empty?
  # included to make this class :respond_to? :empty for compatibility with Active Support's
  # #blank?
  @wrapped_string.empty?
end

#eql?(value) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/kebab/identifier.rb', line 76

def eql?(value)
  @wrapped_string == value
end

#normalize!(options = nil) ⇒ Object

Normalize the string for use as a URL slug. Note that in this context, normalize means, strip, remove non-letters/numbers, downcasing, truncating to 255 bytes and converting whitespace to dashes.

Parameters:

  • Options

Returns:

  • String



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# File 'lib/kebab/identifier.rb', line 148

def normalize!(options = nil)
  options = default_normalize_options.merge(options || {})

  if translit_option = options[:transliterate]
    if translit_option != true
      transliterate!(*translit_option)
    else
      transliterate!(*options[:transliterations])
    end
  end
  to_ascii! if options[:to_ascii]
  clean!
  word_chars!
  clean!
  downcase!
  truncate_bytes!(options[:max_length])
  with_separators!(options[:separator])
end

#normalize_utf8! ⇒ Object

Perform Unicode composition on the wrapped string.

Returns:

  • String



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# File 'lib/kebab/identifier.rb', line 248

def normalize_utf8!
  @wrapped_string = @@utf8_proxy.normalize_utf8(@wrapped_string)
end

#tidy_bytes! ⇒ Object

Attempt to convert characters encoded using CP1252 and IS0-8859-1 to UTF-8.

Returns:

  • String



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# File 'lib/kebab/identifier.rb', line 255

def tidy_bytes!
  @wrapped_string = @@utf8_proxy.tidy_bytes(@wrapped_string)
end

#to_ascii! ⇒ Object

Delete any non-ascii characters.

Returns:

  • String



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# File 'lib/kebab/identifier.rb', line 194

def to_ascii!
  @wrapped_string = @wrapped_string.gsub(/[^\x00-\x7f]/u, '')
end

#to_identifier ⇒ Object Also known as: to_slug 



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# File 'lib/kebab/identifier.rb', line 269

def to_identifier
  self
end

#to_ruby_method!(allow_bangs = true) ⇒ Object

Normalize a string so that it can safely be used as a Ruby method name.



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# File 'lib/kebab/identifier.rb', line 168

def to_ruby_method!(allow_bangs = true)
  leader, trailer = @wrapped_string.strip.scan(/\A(.+)(.)\z/).flatten
  leader          = leader.to_s
  trailer         = trailer.to_s
  if allow_bangs
    trailer.downcase!
    trailer.gsub!(/[^a-z0-9!=\\?]/, '')
  else
    trailer.downcase!
    trailer.gsub!(/[^a-z0-9]/, '')
  end
  id = leader.to_identifier
  id.transliterate!
  id.to_ascii!
  id.clean!
  id.word_chars!
  id.clean!
  @wrapped_string = id.to_s + trailer
  if @wrapped_string == ""
    raise Error, "Input generates impossible Ruby method name"
  end
  with_separators!("_")
end

#transliterate!(*kinds) ⇒ Object Also known as: approximate_ascii!

Approximate an ASCII string. This works only for Western strings using characters that are Roman-alphabet characters + diacritics. Non-letter characters are left unmodified.

string = Identifier.new "Łódź
string.transliterate                 # => "Lodz, Poland"
string = Identifier.new "

You can pass any key(s) from Characters.approximations as arguments. This allows for contextual approximations. Various languages are supported, you can see which ones by looking at the source of Transliterator::Base.

string = Identifier.new "Jürgen Müller"
string.transliterate                 # => "Jurgen Muller"
string.transliterate :german         # => "Juergen Mueller"
string = Identifier.new "¡Feliz año!"
string.transliterate                 # => "¡Feliz ano!"
string.transliterate :spanish        # => "¡Feliz anio!"

The approximations are an array, which you can modify if you choose:

# Make Spanish use "nh" rather than "nn"
Kebab::Transliterator::Spanish::APPROXIMATIONS["ñ"] = "nh"

Notice that this method does not simply convert to ASCII; if you want to remove non-ASCII characters such as “¡” and “¿”, use #to_ascii!:

string.transliterate!(:spanish)       # => "¡Feliz anio!"
string.transliterate!                 # => "¡Feliz anio!"

Parameters:

  • *args (Symbol)

Returns:

  • String



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# File 'lib/kebab/identifier.rb', line 119

def transliterate!(*kinds)
  kinds.compact!
  kinds = [:latin] if kinds.empty?
  kinds.each do |kind|
    transliterator = Transliterator.get(kind).instance
    @wrapped_string = transliterator.transliterate(@wrapped_string)
  end
  @wrapped_string
end

#truncate!(max) ⇒ Object

Truncate the string to max characters.

Examples:

"üéøá".to_identifier.truncate(3) #=> "üéø"

Returns:

  • String



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# File 'lib/kebab/identifier.rb', line 202

def truncate!(max)
  @wrapped_string = unpack("U*")[0...max].pack("U*")
end

#truncate_bytes!(max) ⇒ Object

Truncate the string to max bytes. This can be useful for ensuring that a UTF-8 string will always fit into a database column with a certain max byte length. The resulting string may be less than max if the string must be truncated at a multibyte character boundary.

Examples:

"üéøá".to_identifier.truncate_bytes(3) #=> "ü"

Returns:

  • String



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# File 'lib/kebab/identifier.rb', line 213

def truncate_bytes!(max)
  return @wrapped_string if @wrapped_string.bytesize <= max
  curr = 0
  new = []
  unpack("U*").each do |char|
    break if curr > max
    char = [char].pack("U")
    curr += char.bytesize
    if curr <= max
      new << char
    end
  end
  @wrapped_string = new.join
end

#upcase! ⇒ Object

Perform UTF-8 sensitive upcasing.

Returns:

  • String



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# File 'lib/kebab/identifier.rb', line 236

def upcase!
  @wrapped_string = @@utf8_proxy.upcase(@wrapped_string)
end

#with_separators!(char = "-") ⇒ Object Also known as: with_dashes!

Replaces whitespace with dashes (“-”).

Returns:

  • String



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# File 'lib/kebab/identifier.rb', line 230

def with_separators!(char = "-")
  @wrapped_string = @wrapped_string.gsub(/\s/u, char)
end

#word_chars! ⇒ Object

Remove any non-word characters. For this library’s purposes, this means anything other than letters, numbers, spaces, newlines and linefeeds.

Returns:

  • String



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# File 'lib/kebab/identifier.rb', line 139

def word_chars!
  @wrapped_string = (unpack("U*") - Kebab::STRIPPABLE).pack("U*")
end