Class: Babosa::Identifier

Inherits:
Object
  • Object
show all
Defined in:
lib/babosa/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 Babosa::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  # => <Babosa::Identifier:0x000001013e1590 @wrapped_string="hello-world">

See Also:

Constant Summary collapse

@@utf8_proxy = 
if Babosa.jruby15?
  UTF8::JavaProxy
elsif defined? Unicode
  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/babosa/identifier.rb', line 63

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/babosa/identifier.rb', line 58

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/babosa/identifier.rb', line 33

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/babosa/identifier.rb', line 48

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/babosa/identifier.rb', line 54

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

Instance Method Details

#==(value) ⇒ Object 



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# File 'lib/babosa/identifier.rb', line 69

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/babosa/identifier.rb', line 123

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/babosa/identifier.rb', line 259

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/babosa/identifier.rb', line 227

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

#empty? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/babosa/identifier.rb', line 77

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/babosa/identifier.rb', line 73

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/babosa/identifier.rb', line 139

def normalize!(options = nil)
  # Handle deprecated usage
  if options == true
    warn "#normalize! now takes a hash of options rather than a boolean"
    options = default_normalize_options.merge(:to_ascii => true)
  else
    options = default_normalize_options.merge(options || {})
  end
  if options[:transliterate]
    transliterate!(*options[:transliterations])
  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/babosa/identifier.rb', line 233

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/babosa/identifier.rb', line 240

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/babosa/identifier.rb', line 179

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/babosa/identifier.rb', line 254

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/babosa/identifier.rb', line 160

def to_ruby_method!(allow_bangs = true)
  leader, trailer = @wrapped_string.strip.scan(/\A(.+)(.)\z/).flatten
  if allow_bangs
    trailer.downcase.gsub!(/[^a-z0-9!=\\\\?]/, '')
  else
    trailer.downcase.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
  with_separators!("_")
end

#transliterate!(kind = nil) ⇒ 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, Poland"
string.transliterate                 # => "Lodz, Poland"
string = Identifier.new "日本"
string.transliterate                 # => "日本"

You can pass any key(s) from Characters.approximations as arguments. This allows for contextual approximations. Danish, German, Serbian and Spanish are currently supported.

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!"

You can modify the built-in approximations, or add your own:

# Make Spanish use "nh" rather than "nn"
Babosa::Characters.add_approximations(:spanish, "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/babosa/identifier.rb', line 115

def transliterate!(kind = nil)
  transliterator = Transliterator.get(kind || :latin).instance
  @wrapped_string = transliterator.transliterate(@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/babosa/identifier.rb', line 187

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/babosa/identifier.rb', line 198

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/babosa/identifier.rb', line 221

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/babosa/identifier.rb', line 215

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/babosa/identifier.rb', line 130

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